Product Report

PRIMETECH PROJECT DESIGN: ELECTRONIC DOG COLLAR TEAM MEMBERS: Director: AYLMER ALFREDO AMBU Documentation Manager: ISNARAISSAH MUNIRAH MAJILIS Technical Manager: THIAN NYUK HOW Website Manager: LIM KOK LEONG Presentation Manager: MOHD AZLAN BIN MALLA

DATE OF SUBBMISSION: 15 APRIL 2009

Executive Summary Team Primetech Electronics, throughout this course, have been assigned to build an electronic dog collar for the purpose of dogs breeding. As for an introduction, an electronic dog collar or widely known as the collar trainer, remote trainer or e-trainer, is an electric current generated collar that can be activated by a handheld device. The electric current is meant to interrupt behavior when the dog is exhibiting unwanted behavior or any other means of control. Different types of collar exists in the market today and often a better quality collar trainers have a large variety of levels, which can give varying duration of electric current, and with a beep or vibration option useful for getting the dog’s attention. Different types of collar leads to different types of application method, thus creating different needs and expectation from the users. Understanding these needs and expectation is compulsory for the project. As for the team, Primetech Electronic was able to build an electronic dog collar model that utilizes basic technology and that is low in cost, yet, functions as satisfactory as a typical one. The final result is a prototype that models a remote trainer as it will be controlled by a wireless controller and that no wire/cable will be used as a medium of communication between the two devices. Technically speaking, the remote trainer will generate high voltage-low current (approximately 1000 Volt) from a very low DC source when initiated on a wireless controller unit. Under this operation mode, it must be stated that the application to a dog is completely safe according to the analysis carried out. To sum up, the design is fully functional but somehow restricted in terms of complexity and financial cost to comply with our eight weeks time limit and RM250 university subsidy.

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Acknowledgement We would like to express my gratitude and many thanks to the University for providing this project design class and the project subsidy. It really helped us in understanding the true meaning of working as a team and dealing with a problem when given a very restricted circumstances. We would also like to thank Mr. Liau Chung Fan for being such a dedicated and helpful lecturer for the course. Your idea and aspiration is throughout the course really inspires us and motivate our team to keep pushing hard at any moment. Next, I would like to thank to our dog enthusiasts, Mr. Denzil and Dr. Siva. Your passion in dog training had really thought us the beauty of dog training and inspires us to achieve our goal even more. We would also thank to the sources that we have used in order to progress in our project and provide this report. Last but not least, we would like to thank to anyone that is not listed and had been sharing our ups and downs. Your support is gladly appreciated.

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Table of contents Executive Summary Acknowledgement Table of contents Chapter 1: Introduction and Background

1

Chapter 2: Exploring the solution space and selecting a specific approach

7

Chapter 3: Technical Details

12

3.1 3.2 3.3 3.4 3.5 3.6

Tasser/Dazer Circuit Concept Feedback tasser circuit Printed circuit board (PCB) Relay Wireless Communication Circuit Casing

Chapter 4: Test data with proof of functional design

12 18 23 24 28 49 63

4.1 Concept of Electronic Dog Collar

63

4.2 Operation of Electronic Dog Collar

73

4.3 Testing on WirelessCommunication

85

Chapter 5: Final cost, schedule, summary and conclusions

90

Appendix 1

96

Appendix 2

106

Appendix 3

107

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Chapter 1 Introduction and Background

When it comes to dog training, immediate correction has proven to be the most essential method in achieving its goal. The term immediate correction here visualizes; the moment the dog exhibit misbehavior that is the time we should be telling it not to behave such a way. Since dogs cannot comprehend human language, one of the most effective ways to discipline them is by inducing a tolerable pain. (Dogs attitude is mostly influenced by fear and pain.) Several training aids can be seen on the market today as an extra tool to help a trainer/breeder to train their dog to be behave better. Among them is the electronic dog collar, better known as the training collar. A training collar is a unique and invaluable tool that will help breeder to correct the dog the instant it misbehaves. Dog training collars gives the main importance in dog training which is all about communicating with the dog and it is not intended as a form of punishment. Basically it limits a dog’s behavior to a certain extend which in the whole process of dog training will let the dog understand that there are certain boundaries it cannot exceed.

Since a training collar allows a breeder to communicate with the dog

immediately after a certain behavior has taken place, the dog will quickly understand that there is a connection between the behavior and the electric stimulation. This will teach the dog that it is in control and that by refraining from the negative behavior he eliminates the collar stimulation. Early shock collars was initially created with the purpose of redirecting hunting dogs who were diverted from their determined job by distractions such as prey animals that were not being hunted by the handler but being chased by the hunting dog. These collars were bulky and unsophisticated in terms of stimulation. 1

The early models had significant limitations where the punishment given to the dogs were inhumane. Collar designers soon realized that there were many applications for a collar that could help them redirect the dog when it is far away or distracted. The popularity of these devices expanded from sport dog owners to companion dog owners and service dog trainers. Nowadays, modern developments have seen significant improvement in reliability and sensitivity. Most current devices deliver a controlled electric current, ranging from low levels of stimulation that is usually creating a tickling or tingling effect to medium levels to high levels that is capable of causing significant discomfort. Modern electronic dog collars are also designed so that it is highly unlikely for another electronic signal to set them off, which is another consideration to be weighed in using one.

In terms of public acceptance, electronics dog collar is a popular device to control your dog’s behaviour nowadays. Behaviour dog training is very important in today's society because many people take their dogs everywhere they go. This electronics product is worn on a dog’s neck. There are a few established international companies which already produced various types of dog collar such as PAC dog trainer, Pet street mall, Seefido and others with main goaldog training. As an addition to the application of the collar, breeder/trainer may also combine it with the application of the traditional leash just to make sure the level of control is within satisfaction. Besides it is always good to have on should the dog reacts extremely wild and able to overcome the level of charge execution of the collar.

The reasons in the practice of this device vary accordingly with the different needs by the end user. As for dog training this device helps to prevent unwanted dogs behaviour including digging, trash raiding, chasing and jumping. This is also applied to unnecessary dogs barking.

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Figure 1.0 (a, b, c, d): Application of the electronic dog collar

We must accept that not all dogs respond to standard "compulsive" or "reward" training methods, and, until you encounter a difficult dog, it is hard to imagine the need for a collar trainer. The use of such a tool, as a last resort, can be extremely effective in curing a comprehensive range of problems as quickly and usually pain-free.

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Correct use of the device will inevitably promote the trainer to surrogate 'pack-leader' or 'top dog' and will allow him to be far less physical with his dog. If verbal commanding isn't stopping your dog from barking, an electronic dog collar may be necessary. The usage device will let dog breeder to immediately correct your dog whenever it is out of well-behaviour by sending light electrical shock for a short moment. The utilisation of the device in dog training has been recognized and has proven to be very effective. Aside from its quality as a training aid, it is also safe and reliable as well.

On figure 1.1 and figure 1.2 are two examples of electronic dog collars that are available in the current market. They are available in different weights, styles, operation intensities, and functionalities to suit every need and breed. Depending on the specification set by the collar trainer company, the lower spec/basic unit comes in just a basic switch on-switch off function while some other higher spec units allow you to set variable intensities, and nearly all collars warn the dog before the correction by sounding an alarm. Generally dog training collars can be seen grouped into two different types which are the basic dog training collar and advance dog training collar. The different really lies on the criteria described earlier. An advance type basically have more advantage to the basic type as there are more fancy option such as the LCD display and etc. Some collars also feature a vibrating alarm, which warns your dog but doesn't shock him. Large or stubborn dogs may require a stronger model of shock collar, or one that emits a longer shock than most.

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Figure 1.1: Basic dog training collar

Figure 1.2: Advance dog training collar 5

As for the project, team Primetech Electronic is assigned to design and build an electronic dog collar model that utilizes basic technology and that is low in cost, yet, functions as satisfactory as a typical one. The primary idea is to let the end user to control their dog’s behavior from a distance through a wireless control unit. This wireless control unit is the one that will be controlling the circuit activity on the dog collar. Our main objective throughout the entire project is to come up with a working electronic dog collar that is technically similar and satisfying as the other existing product in the market.

However, the main cause that may

hinder our achievements is the lack of machinery equipment that could help us in producing a market-ready product. Adding to the pain, the very limited project budget had also limited the creativity and the productiveness of the team. Despite the entire unfavorable scenario, we are satisfied to be able to finally produce a working electronic dog collar.

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Chapter 2 Exploring the solution space and selecting a specific approach Although electronic dog collar is widely sells in the internet especially in the United States and Canada region, it is not available in local market. It was quite hard to gather and collect information about this tool initially. To determine the customer requirements, Primetech Electronics have met with our client who is a dog breeder. Initially, the dog breeder requires our team to produce a waterproof and shockproof electronic dog collar.

Problems

1.battery -

The first problem which occurred in the circuit was the power supply. The power supplied last only for 1 day maximum according to the user usage. This will cause inconvenience to the customer. Somehow, it is found that the electronics dog collar power supply is very fast to be fully-used. According to the dog breeder, the electronic dog collar which he once bought in the US was slightly the same. The power supply will be fully-used within 2-3 hours only, and he had to change battery often. Until this point, Primetech Electronics does not have any solution for this since this is a common problem.

2. Casing - Casing plays the important part in producing a good electronic dog collar. Casing is one of the safety tools which will protect not only the circuit inside it but as well as the dog. It is a very important to produce a durable and waterproof casing. The size does matter as well. The size that needed to produce must be as small as possible. 7

This is so much needed since the electronic dog collar will be place at the dog neck. It is very crucial to think about the dog’s reaction and convenience and whether the electronic dog collar can fit a moderate dog size.

3. Waterproof - Most dogs produce lots saliva especially when they are hungry or tired. The client required a waterproof electronic dog collar to Initial Gannt chart:

Figure 2.1 Initial Gannt-Chart

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Initial Budget Initial estimate of course Item

Unit Price

Quantity

Total

Ac-Dc Power Supply

RM18.00

1

Rm18.00

PIC16F877A

RM30.00

2

RM60.00

RF Transmitter

RM35.00

1

RM25.00

RF Receiver 433Mhz

RM25.00

1

RM35.00

Capacitor 0.03uF

RM3.00

1

RM3.00

Capacitor 0.03uF 800V

RM2.70

1

RM2.70

Transformer

RM5.00

1

RM5.00

Transistor 3904

RM0.50

5

RM2.50

Transistor cs8050

RM0.50

1

RM0.50

Potential Meter 1M

RM3.00

1

RM3.00

Zener Diode 10V

RM0.70

2

RM1.40

Zener Diode 20V

RM0.70

2

RM1.40

Diode ln4007

RM0.30

2

RM0.60

433Mhz

1000V

ohm

9

Zener Diode 12V

RM0.70

2

RM1.40

Resistor 10k ohm

RM0.20

3

RM0.60

Resistor 10M ohm

RM0.30

2

RM0.60

Resistor 470 ohm

RM0.20

1

RM0.20

Resistor 820 ohm

RM0.20

1

Rm0.20

Toggle Switch

RM1.50

2

RM3.00

Push Button

RM4.00

10

RM4.00

Crystal 20Mhz

RM2.50

2

RM5.00

Capacitor 100uF 25V

RM0.40

4

RM1.60

5V Voltage Regulator

RM1.50

3

4.50

RM0.20

10

RM2.00

RM0.20

10

RM2.00

Relay 5v

RM1.50

1

RM1.50

LED

RM0.20

10

RM2.00

TOTAL

RM186.70

7805 Resistor 330 ohm 0.25w Resistor 4.7k ohm 0.25w

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PCB development, laser printing, soldering lit,

RM21.00

PCB photo resist board Report and other tasks printing

RM45.00

Power supply (batteries)

RM 11.00

Casing development

RM20.00

TOTAL

RM97.00

ALL TOTAL

RM283.70

Fast Diagram:

How?

Why?

Calculate ranges of suitable resistors that can produce desired output voltage value

Produce different ranges of voltages

Using Feedback circuit

Test output voltage

Failed

Feedback is not suitable to used in this circuit

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Chapter 3 Technical Details The production of the actual working electronic dog collar involves several procedures. Following these procedures, the device will finally take shape and that we may organize its from-birth-record and use it for any related analysis and most importantly for troubleshooting if any problem arises. As explained before, the project consists of the development of two primary devices which are the electronic dog collar itself and the wireless controller unit. Each of these devices has their own unique approach to be built and is not restricted to a single follow-thebook method. The design does not end there as there are other vital issues including the casing development of each circuit. Therefore, to provide a comprehensive detail about each design that had took place, we have divided them into several sub-topics and explained them separately. 3.1 Tasser/Dazer Circuit Concept In the primary idea out of numerous brainstorming sessions, we have opted to use the tasser circuit approach in the formation of the project. A tasser circuit which is known for its capability of producing a very high voltage output with low current output out of a relatively small power supply makes it the best option to be implemented in the design of our electronic dog collar. The tasser circuit may then be combined with other technique (explained later in this chapter) to form the final product. As an introduction, a tasser is basically an electronic device which comprises few electrical and/or electronic components that are connected delicately with the intention of generating a high voltage output. This output is generated with a relatively low power supply. The characteristic of this output would be a high voltage but with low current.

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This is to ensure safety for the user as although with high voltage exposure, but with low current the device could hardly harm or kill the end user. It is just a matter of controlled amount of jolt (charge) released by the capacitor at a fraction of time at the output terminal. Depending on the voltage source, transformer and voltage multiplier configuration, the output can be varied from the lower (under 1kV) to the extreme atmosphere voltage breakdown point (over 33kV!). The basic construction of a tasser circuit involved but not limited to using of transformer as a basic voltage step-up and to the voltage multiplier which utilize capacitor as the container for the charging and discharging of potential. The transformer: 

An approximate 1:55 turns ration transformer was adapted from a mosquito bat (You may find a similar one from other electrical device. Example: Disposable camera).



The specific transformer that we had in mind to be used was not readily available in the local market and therefore we had to adapt it from another electrical device.



3V input supply was applied to obtain a generated 500V on the secondary side of the transformer. It is important to note that when voltages are stepped up, current is decreased; when voltages are stepped down, current is increased.



Another key feature of the transformer is that it is able to oscillate the input to produce an oscillating output at the secondary side.



This oscillation behavior is obtained as the internal inductor/winding of the transformer tends to oscillate it (The transformer actually needs oscillating voltage to be in the ON mode).



The output at the secondary terminal of the transformer can be up rated further by the implementation of the technique called voltage multiplier.



The application of the transformer is illustrated in the tasser circuit diagram attached. 13

The Voltage multiplier/doublers You may already know how a transformer functions to increase or decrease voltages. You may also have learned that a transformer secondary may provide one or several ac voltage outputs which may be greater or less than the input voltage. When voltages are stepped up, current is decreased; when voltages are stepped down, current is increased. Another method for increasing voltages is known as voltage multiplication. Voltage multipliers are used primarily to develop high voltages where low current is required. The dc output of the voltage multiplier ranges from 1 kV to 30 kV. As we know transformers, you may have learned that when voltage is stepped up, the output current decreases. This is also true of voltage multipliers. Although the measured output voltage of a voltage multiplier may be several times greater than the input voltage, once a load is connected the value of the output voltage decreases. Also any small fluctuation of load impedance causes a large fluctuation in the output voltage of the multiplier. For this reason, voltage multipliers are used only in special applications where the load is constant and has high impedance or where input voltage stability is not critical. Voltage multiplier/doublers circuit architecture:

If we rearrange the diode and capacitor in the negative half of the voltage double circuit above, we get the circuit shown below. This time, one end of the secondary winding is grounded, so that is our reference point. The ungrounded end will be driven alternately negative and positive with respect to ground. This circuit operates in a manner that is not quite as straight-forward as the original voltage doublers we examined.

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To understand the operation of this circuit clearly, we need to take a detailed look at it during successive half-cycles of the ac input from the transformer. We will initially assume ideal components and that C1 = C2

Figure 3.1: Half-wave voltage doublers circuit 

During the first negative half-cycle, D1 will be forward biased and will hold the right end of C1 at ground. Therefore C1 will charge to a voltage equal to the peak voltage (vp) of the transformer winding, with its left end being negative with respect to ground.



During the following positive half cycle, D1 will be reverse biased and therefore will not conduct current. The voltage on C1 will add to the transformer output voltage, so a voltage of 2vp will appear at the left end of D2. Since C2 is not yet charged at all, this will forward bias D2 and allow the voltage at the right end of C1 to be applied to the top of C2. C2 will charge as C1 discharges, until the two capacitors can no longer forwardbias D2. For the first positive half-cycle, the voltage on C2 will be equal to vp, and C1 will be completely discharged, so that all the voltage at the left end of D2 comes from the transformer winding. 15



On the next negative half-cycle, C1 charges again to vp, through D1. If there is no load to discharge C2, its output will remain at +vp.



On the second positive half-cycle, C2 is still charged to +vp, while the voltage at the left end of D2 is again +2vp. Again, C1 transfers part of its charge to C2, but this time they stop when C2 is charged to a voltage of +1.5vp.



This action continues, cycle by cycle, with C1 being fully recharged to vp on each negative half cycle, and then charging C2 to a voltage halfway between its starting voltage and +2vp. C2 will never quite charge to +2vp, but it will come very close.



With real-world components, of course, there is a small voltage drop across each diode when it is forward biased. Also, any load on this circuit will draw current from C2 at all times, thus discharging this capacitor to some extent. However, on each positive halfcycle, C1 will recharge C2 from the voltage it had at the start of the half-cycle halfway up to +2vp.



Note that the output current capacity of this circuit is still only half the current capacity of a normal rectifier circuit. Any attempt to draw additional current from the voltage doublers will simply cause C2 to discharge faster, thus reducing the output voltage. It is never possible to get more power out of the voltage doublers than goes into it.



We can speed up the charging and recharging of C2 if we make C1 larger than C2. For example, if C1 = 100µf and C2 = 10µf, C1 can transfer much more charge to C2 on each positive half-cycle, and the voltage on C2 will increase much faster than the voltage on C1 will decrease. Of course, this also means that the output current capacity is even more limited, since C2 will discharge rapidly as well as charging rapidly.

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Figure 3.2: Half-wave voltage doublers circuit and waveform

The final tasser circuit: As we technically discussed about the half-wave voltage doubler above, it is possible to combine it with the 1:55 transformer that we have in order to create a 1kV tasser circuit. The complete architecture of the tasser circuit is describe as follows: 

As the 3V supply is connected, the circuit is activated.



A current will flow across the resistor R1 and activating the L.E.D to indicate that the circuit is switched ON.



Another corresponding current will flow across winding L2. Current will not flow across winding L1 since that the transistor T1 is now in OFF state. The current that is flowing through winding L2 will then flow to the transistor T1 and thus activating transistor T1 to ON state.



Upon activation of transistor T1, a current can now flow through the winding L1 of the transformer and begin stepping up the voltage to supply it to the secondary side L3.

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

From L3, an approximate 500V had been stepped up with a lower current rating. Using the theory of the voltage double for a halv-wave voltage multiplier, a voltage can be multiplied double.



A 10M-Ohms resistor is connected parallel with the capacitor C2 to discharge the potential to the subject. At this point, the voltage is approximately 1kV and the current rating had been lowered further.

Figure 3.3: Tasser circuit diagram

3.2 Feedback tasser circuit In this project, to prevent the output voltage over the desire voltage level (purpose is to generate different output voltage) so a feedback control system is needed to feed unwanted output voltage to input (BJT)

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Figure 3.4: Feedback concept Feedback describes the situation when output from (or information about the result of) an event or phenomenon in the past will influence the same event/phenomenon in the present or future. When an event is part of a chain of cause-and-effect that forms a circuit or loop, then the event is said to "feed back" into itself. Figure 3.5 below show about type of feedback.

Figure 3.5: The implementation of the feedback circuit

From the circuit, we know feedback is to produce or different voltage to control output voltage. So, we use the feedback to proposed ranges voltage to 500V, 800V, and 1kV.

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Figure 3.6

PROBLEM (WHY IT FAILS) Why we have to calculate the value of R2?

To make sure that the voltage flow across zener diode is 20V. The voltage must less than 20V to turn ON the zener diode.

Through voltage divider calculation, if we want to produce 1000V, the voltage at R2 is equal to the value of zener diode thet is 20V. So, voltage at R1 equal to 980V.

Apply calculation, (Figure 3.6)

Desire output voltage = 1000V

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Figure 3.7

But, as we apply R2 = 204kΩ, the output voltage is only 900V instead of 1000V

Desire output voltage = 800V

Let’s calculate for output voltage equal to 800V. As previous, voltage at R2 is equal to 20V same as the value of zener diode. So, that’s make voltage at R1 is equal to 780V. Apply voltage divider rule,

Apply calculation, (Figure 3.7)

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Figure 3.8 Desire output voltage = 500 V

There goes the same to output voltage equals to 500V. Through voltage divider rules calculation is equal to 20V through we apply R2 equals 416kΩ, but still we get output voltage equal to 900V not desire output voltage 500 V.

From the experiment above, using feedback system to get several output voltage is fail this is because when feedback system is trigger it will off the operation of circuit (restart and redo) so that is only one output voltage value, 900V

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3.3 Printed circuit board (PCB)

PCBs are boards where upon electronic circuits have been etched. PCBs are rugged, inexpensive, and can be highly reliable. They require much more layout effort and higher initial cost than either wire-wrapped or point-to-point constructed circuits, but are much cheaper and faster for high-volume production. Much of the electronics industry's PCB design, assembly, and quality control needs are set by standards that are published by the proteus software. Firstly, do the circuit or schematic diagram. Then, circuit is converted to the PCB layout. To produce a PCB layout software that can be used are the proteus software and ipc software. Before do the PCB layout, we must measure the length and the width of the components so that the component can be placed accurately on the PCB board. After measure all the component and can do the PCB. Some PCBs have trace layers inside the PCB and are called multi-layer PCBs. After that, before print the PCB layout must convert to adobe reader so that easy to print. Besides that, printing must be in transparent paper. Next, do the ultraviolet the PCB for scan the layers inside the PCB. Then, go to chemical part where the layer will appear on the PCB. This is because for easy to do the etching. After that, etching will do to erase the copper not use in the PCB. Etching part will take 15 minutes. After that, the PCB must develop for decrease the acid. Besides that, we also do the drilling on PCB. The holes through a PCB are typically drilled with tiny drill bits made of solid tungsten carbide. Next step is soldering the component. Areas that should not be soldered to may be covered with a polymer solder resist (solder mask) coating. The solder resist prevents solder from bridging between conductors and thereby creating short circuits.

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Solder resist also provides some protection from the environment. Finally, test the circuit function or not. If not, troubleshoot the circuit to find the problem the circuit.

3.4

Relay

A relay is an electrical operated switch that opens and closes under the control of another electrical circuit. In the original form, the switch is operated by an electromagnet to open or close one or many sets of contacts. It was invented by Joseph Henry in 1835. Because a relay is able to control an output circuit of higher power than the input circuit, it can be considered to be, in a broad sense, a form of an electrical amplifier.

Basic Design

Figure 3.9: Simple electromechanical relay

Figure 3.10: Small relay as used in electronics 24

These two pictures above are example of a relay. It consists of a coil of wire surrounding a soft iron core, an iron yoke, which provides a low reluctance path for magnetic flux, a moveable iron armature and a set, or sets, of contacts; two in the relay pictured. The armature is hinged to the yoke and mechanically linked to a moving contact or contacts. It is held in place by a spring so that when the relay is de-energised there is an air gap in the magnetic circuit.

In this condition, one of the two sets of contacts in the relay pictured is closed, and the other set is open. Other relays may have more or fewer sets of contacts depending on their function. The relay in the picture also has a wire connecting the armature to the yoke.

This ensures continuity of the circuit between the moving contacts on the armature, and the circuit track on the Printed Circuit Board (PCB) via the yoke, which is soldered to the PCB.

How Does A Relay Operate? When an electric current is passed through the coil, the resulting magnetic field attracts the armature and the consequent movement of the movable contact or contacts either makes or breaks a connection with a fixed contact. If the set of contacts was closed when the relay was de-energised, then the movement opens the contacts and breaks the connection, and the other way round if the contacts were open. When the current to the coil is switched off, the armature is returned by a force, approximately half as strong as the magnetic force, to its relaxed position. Usually this force is provided by a spring, but gravity is also used commonly in industrial motor starters. Most relays are manufactured to operate quickly. In a low voltage application, this is to reduce noise. In a high voltage or high current application, this is to reduce arcing.

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Types of relay

1. Latching relay

- has two relaxed states (bistable)

- Also known as ‘keep’ or ‘stay’ relays

- When the current is switched off, the relay remains in its last state

- This type of relay has the advantage that it consumes power only for an instant, while it is being switched, and it retains its last setting across a power outage

2. Reed relay

- has a set of contacts inside a vacuum or inert gas filled glass tube which protects the contacts against atmospheric corrosion.

- Reed relays are capable of faster switching speeds than larger types of relays, but have low switch current and voltage ratings

3. Mercury-wetted relay

- is a form of reed relay in which the contacts are wetted with mercury.

- used to switch low-voltage signals (1volt or less) because of their low contact resistance or for high-speed counting and timing applications where the mercury eliminates contact bounce

- since of the toxicity and expense of liquid mercury, these relays are rarely specified for new equipment 26

4. Machine Tool Relay

- is a type standardized for industrial control of machine tools, transfer machines, and other sequential control

- They are characterized by a large number of contacts (sometimes extendable in the field) which are easily converted from normally-open to normally-closed status, easily replaceable coils, and a form factor that allows compactly installing many relays in a control panel.

5. Contactor Relay

- is a very heavy-duty relay used for switching electric motor and lighting loads.

- High-current contacts are made with alloys containing silver. The unavoidable arcing causes the contacts to oxidize and silver oxide is still a good conductor. Such devices are often used for motor starters.

- A motor starter is a contactor with overload protection devices attached. The overload sensing devices are a form of heat operated relay where a coil heats a bi-metal strip, or where a solder pot melts, releasing a spring to operate auxiliary contacts.

- These auxiliary contacts are in series with the coil. If the overload senses excess current in the load, the coil is de-energized.

- Contactor relays can be extremely loud to operate, making them unfit for use where noise is a chief concern.

6. Solid State Contactor Relay

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- is a very heavy-duty solid state relay, including the necessary heat sink, used for switching electric heaters, small electric motors and lighting loads; where frequent on/off cycles are required.

- There are no moving parts to wear out and there is no contact bounce due to vibration.

- They are activated by AC control signals or DC control signals from Programmable logic controller (PLCs), PCs, Transistor-transistor logic (TTL) sources, or other microprocessor controls.

3.5

Wireless communication

3.5.1 Hardware: 3.5.1.1 RF-Module (433MHz) i)

RF Transmitter Module

Figure 3.11: RF Transmitter Module (433MHz)

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Table 3.1 Specification of RF- Transmitter Module Specifications

RF Transmitter Module

Operating Voltage

3V to 12 V

Operating Current

Max: 400mA for 12 V supply Min: 9mA for 3V supply

Frequency

433MHz

Transfer Rate

10Kbps

Antenna Length

18cm

There are 3 pins to connect in the RF Transmitter module. The DATA pin is connected to the TX pin of the Microcontroller. VCC pin connect to the supply voltage and GND connect to ground. The antenna can extend with any wire but for better result, a 50 Ohm coaxial cable is used. The length of the wire as antenna is about 18cm long.

ii) RF-Receiver Module

Figure 3.12: RF Receiver Module (433MHz)

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Table 3.2 Specification of RF-Receiver Module Specifications

RF Receiver Module

Operating Voltage

5.0V ± 0.5V

Operating Current

≤5.5mA for 5.0V supply

Frequency

433MHz

Transfer Rate

10Kbps

Antenna Length

18cm

There are 5 pin to connect for the RF receiver module. The DATA pin of the RF Receiver Module is connecting to the RX pin of microcontroller. The VCC pin connects to the 5v supply and the GND pin to ground. The ANT is the antenna of the receiver and can be extend with any wire. The length of the wire is 18cm for better result.

3.5.2 Microcontroller i)

PIC16F877A

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PIC16F877A is an 8-bit microcontroller. It has 5 I/O port where each I/O port have 8 I/O pins. There is 8 A/D input and 15 interrupt. There also implemented with parallel Slave port in this microcontroller. Table below shows the specification PIC16F877A.

ii) PIC16F628A

PIC 16F628A is an 8-bit microcontroller. It has 2 I/O port where each I/O port have 8 I/O pins. There is no A/D input and 10 interrupt. Table below shows the specification of PIC16F628A.

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Table 3.3: The specification of PIC16F877A and 16F628A Model

Operating

Flash

Frequency

Interrupt

Capture/

Serial

I/O

10-bit

Memory

Compare/PWM

Communications

Port

Analog-to-

(world)

modules

Digital Module

16F877A

DC-20MHz

8K

15

2

USART

5

8 Input channel

16F628A

DC-20MHz

2K

10

1

USART

2

none

3.5.3 Circuit Diagram i)

Transmitter (remote control circuit)

Figure 3.13: Circuit diagram of remote control. PIC16F628A operate in 5v. Hence, 7805 which is a 5 volt voltage regulator is use to regulate the input voltage which is 9 volt to a stable dc 5 volt. 32

Two capacitors are connected to the voltage regulator as shown in the circuit above as a coupling capacitor to reduce the noise in the regulator and allow the regulator to produce a stable dc 5 volt to be supply to the microcontroller. A 20MHz crystal is connected to pin 15 and pin 16 of the PIC as an oscillator. The capacitor connected to the crystal is to reduce noise. The oscillator determined the process speed of the microcontroller. RF transmitter module also needs a 5 volt supply voltage. The Vcc of the pin is connected to the pin 2 of the microcontroller. This is done so that the transmitter input voltage is supply by the microcontroller and the transmitter is always turning off whenever there is no transmitting process going on. From the table 3.1, the transmitter needs at least 9mA to operate and PIC16F628A is able to supply 5 volt with the current of 25mA which is sufficient to operate the transmitter. The data pin of the transmitter is connected to the TX pin of the microcontroller which is pin 8 for PIC16F628A. TX pin is for the use of serial communication interface which will transfer 8 bit data to the transmitter to be transmit. A push button is connected to pin 10 of PIC16F628A to give signal to the microcontroller to start transmit each time the button is press. A low signal (0 volt) is given to the microcontroller to start transmit. To enable the push button give a low signal (0 volt) to the microcontroller, a pull up resistor of 4.7k is connected parallel with the push button. When the switch is open, a high signal (5 volt) signal will be given to the microcontroller. When the switch is close, the current will flow through the resistor to the push button to ground and this will give a low signal to the microcontroller. The 4.7K resistor also prevents the source to be short circuit when the switch is closed.

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LED is connected to the pin 13 as an indicator of the program is running whenever the push button is being press. The 330 ohm resistor is connected in series with the LED in order to protect the LED damage by the current. The LED used operate at a current of 15mA and after adding the 330 ohm resistor series with the LED, the output current of the microcontroller is being reduce to 12mA which is safe for LED. ii) Receiver Circuit

Figure 3.14: Circuit of the receiver and the tasser circuit For PIC16F877A, it is also operating in 5 volt and hence the same regulator as the one used in the circuit of the transmitter shown in Figure 3.12 which is 7805 is used. The coupling capacitor is connected to the regulator in order to reduce noise. A 20MHz crystal is use and is connected to pin 13 and 14 of PIC16F877A. 34

A 5 volt activation relay is used to create an open circuit at the out output of the tasser circuit. The relay operated at 5 volt. When the relay switches to the ‘normally open’ pin, the current will flow from the object at the output to the relay. When the relay switches to the ‘normally closed’ pin, the circuit will remain as open circuit. To be able create an open circuit is very important in so that the capacitor at the multiplier able to charge after discharge. To control the switching of the relay by the microcontroller, a PNP transistor, S8550 is connected as shown in Figure 3.13. The transistor act as a switch and when the microcontroller gives a low signal (0 volt) it will conduct the current to the relay. The relay will switch from the ‘normally closed’ pin to the ‘normally open’ pin. The transistor is an active low switch. The RF receiver is operating at 5 volt. The Vcc pin of the RF receiver is connected to the 5 volt supply from the voltage regulator. The data pin of the receiver is connected to the RX pin which is pin 26 for PIC16F877A. RX pin is for the use of serial communication interface which will receive the 8 bit data from the transmitter for further process. In this circuit, when the receiver receive correct data transmitted from the transmitter, the microcontroller will turn on the relay in order to produce an electric shock on the object at the output. 3.5.4 Battery Indicator Seem the electronic dog collar is a high voltage device which step up a small voltage to high voltage, the duration of the battery is a issue to be discuss. In this project, a pair of AA battery with total 3 volt is used as the input of the dog collar. In order to let the user to know and to check the condition of the battery, a battery indicator system is added to the system. This battery indicator uses an analog to digital convertor (ADC) where convert the analog signal

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from the 3 volt battery to be process. When the battery is around 2.6 volt or lower, it is consider as battery week and the indicator will turn on. By referring to the circuit diagram in Figure 3.13, the positive of the 3 volt battery is connected to the analog to digital pin of the microcontroller which is pin 2. The reference voltage used is 5 volt and hence the calculation for the ADC is shown below: Let x=current voltage of battery in digital form The battery is week at 2.6 volt. The value of x=

The value of 133 is a reference of the condition of the battery. If the reading of the battery is lower than 133 then it is consider as week while if the batter is higher than 133 it is still in good condition. This battery indicator system is not an automatic system which means that it will only check the condition of the battery when the user presses the check button. 3.5.5 Software 3.5.5.1 Interface RF-Module with Microcontroller MPLAB is used as the programming software and assembly language is used as the programming language. To interface RF module with microcontroller, Universal Synchronous and Asynchronous Receiver and Transmitter (USART) or also known as Serial Communications Interface is used. USART is used for transmit and receive serial data. The operation of USART can be divided into two types which is synchronous and asynchronous. Synchronous mode uses a clock and data line. Asynchronous mode does not use clock accompanying the data. Asynchronous mode will be use in interfacing the RF module with the microcontroller. Table below show the register and flag bit that will be used together with its description. 36

Table 3.5 Register and Description which will be used Register Name

Description

TXSTA

Transmit Status and Control

RCSTA

Receive Status and Control

TXREG

Write Transmit Data Register

RCREG

Write Receive Data Register

SPBRG

Setting Baud Rate

PIR1

Peripheral Interrupt Flag Register

PIE1

Peripheral Interrupt Enable Registers

Table 3.6: Description of flag bit that will be used Flag Bit Name

Description

TXIF

Located in PIR1 (bit 4) which is use to check whether TXREG is Full or Empty

RCIF

Located in PIR1 (bit 5) which is use to check whether RCREG is Full or Empty

OERR

To test over run error for the RCREG Register

TXEN

Transmit Enable of Disable bit

3.5.5.2 Theory and Setting Asynchronous Mode of USART for Transmitter In section 5.2, it is shown that the data pin of the transmitter module is connected to the TX pin of the microcontroller. Seem TX pin normally used as a digital I/O port, to enable the TX port as a serial port, SPEN which is bit 7 in RCSTA have to be set. Bit two in TRISB of PIC16F628A have two be clear in order to make the TX pin as an output pin. TXSTA is the transmit control register for the microcontroller. This register has to be initializing correctly in order to make the transmission work. By referring to the data sheet, the TXSTA is initialized as B'00100000' which mean that it transmit 8bit data in asynchronous low speed mode.

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Figure 3.13 shows the representation of each bit of the TXSTA register and Figure 3.15 show the setting of the register in the program.

Figure 3.15: Representation of Each Bit in TXSTA Register

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Figure 3.16: Setting of the Register for USART Next is to set the baud rate of the transmitter. Baud rate refers to the speed at which the serial data is transferred, in bits per second. In Asynchronous mode, the baud rate generator sets the baud rate using the value in the SPBRG register. The BRGH bit in TXSTA selects between high and low speed options for greater flexibility in setting the baud rate. From the initialization of TXSTA shown above, the BRGH is clear which mean that the baud rate is in low speed and the SPBRG register is set to 129 where the rate is 2.4K bit per second. The Baud rate for both transmitter and receiver must be the same in order for the data transmitted to receive in the receiver. The baud rate can be calculated with the formula shown below.

Where, Fosc = frequency of crystal used X= value that will be set in the SPBRG register Example: Taking the desired baud rate = 2.4K

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When a 1 byte digital data is being transmitted, it is transmit from the less significant bit to the most significant bit. This means that the transmitter transmits digital data bit by bit to the receiver. Figure 3.16 shows how the signal is transfer in asynchronous mode.

Figure 3.17: Signal Transfer in Asynchronous mode From Figure 3.16 the signal is high when no transmission (or reception) is in progress and goes low when the transmission starts. The receiving device uses this low-going transition to determine the timing for the bits that follow. The signal stays low for the duration of the START bit, and is followed by the data bits, Least Significant bit first. The USART can transmit and receive either eight or nine data bits. The STOP bit follows the last data bit and is always high. The transmission therefore ends with the pin high. After the STOP bit has completed, the START bit of the next transmission can occur as shown by the dotted lines. During transmitting data, the heart of the transmitter is the Transmit Shift Register (TSR). This register obtain the data from the transmit buffer, TXREG. Hence, to transmit a data to the receiver, first is to move the desire transmit data to the TXREG then it will load to TSR to be transmitted. To check whether the data in TXREG had been move to TSR, the flag bit TXIF which located in the PIR1 is checked. If TXREG is empty (means the data already load to TSR) the flag bit TXIF will be set. Hence new data can be load to TXREG to be transmitted next. The Bit TXEN in TXSTA show in Figure 3.14 is always set so that all the data in TSR will be transmit.

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Check TXIF

False

True

Move data to TXREG to be transmitted

Figure 3.18 Block Diagram Showing the transmitter’s program runs

3.5.5.3 Theory and Setting of Asynchronous Mode of USART for Receiver RCSTA is the receive control register for the microcontroller. This register has to be initializing correctly in order to make the receiver work. By referring to the data sheet, the RCSTA is initialized as B'10010000' which mean that it continuously receive 8 bit data, asynchronous mode. The SPEN Flag bit in RCSTA have to be set to enable the serial port. The baud rate for the receiver has to be the same with the transmitter. Figure 3.18 shows the representation of each bit of the RCSTA register and Figure 3.15 shows the setting of the register in the program.

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Figure 3.19: Representation of Each Bit in RCSTA Register When receiving data from the transmitter, the data is first stall in Receive Shift Register (RSR). After that the received data is transferred to the RCREG register when it is empty. Once the transferring process from the RSR to RCREG is complete, the flag bit RCIF will be set. The RCREG is a double-buffered register which mean that it can store two byte of data. When the 2nd data come in but the 1st data have not been read yet, the data will store in the second slot of the RCREG.

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When the 1st data is read, the 2nd data will move to the 1st slot and new data can be move into RCREG. However, when the RCREG is full and the 3rd data is store in the RSR, the flag bit OERR will be set and the data in RSR will lost. In addition, all the receive process will be stop. Hence it is a must to clear the flag bit OERR in order to retrieve the receiving process. Flag bit OERR can be clear by first clear the CREN and then set it again. Figure 3.19 shows how the overrun error being detected and how it is solve.

Figure 3.20: Sample code detecting and solving overrun error The FERR which stand for framing error bit is used to check framing error. By referring to Figure 3.16, it is clear that the transmitter will transmit a 0 bit as a start bit before it transfer data and a 1 as a stop bit after all the 8 bit data have been transfer. The FERR bit is use to check whether the start bit receive is 0. 43

If the start bit received is 0, it mean no framing error and FERR will be clear. If the start bit receive is 1, it means that the receive 8 bit data contains error and FERR will be set. Hence, by checking the FERR bit, incorrect data receive will be detected without going through further process. Figure 3.20 shows the source codes for detecting error start bit and discard the error data in RCREG register.

Figure 3.21 Sample code for detecting error start bit and discard error data 3.5.6 Transmit and Receive Method There are three type of transmit and receive method that have done and experiment to test the performance of the method. These methods are transmit and receive 1 byte data, transmit and receive with 9th bit as Parity bit, transmit and receive 2 byte data. 3.5.6.1 Transmit and Receive 1 byte data Transmit and receive 1 byte data is the most common and simple wireless communication that can be use. For 8-bit transmission, the 1 byte data is from 1 to 255. To use this type of transmission, first select a number from 1 to 255 to be transmitted to the receiver. The number choose have to be preset in the receiver set in order to let the receiver to compare the data receive is the desired data. For example if a number ‘3’ is choose as a transmit data. At the receiver part the number ‘3’ have to be stored in a file to be use to compare to the incoming data. If the incoming data is ‘3’ then it is true and the program will execute for further action. If the data 44

receive is compare with the pre store ‘3’ and found that it is not the same, and then the program will continue looping to receive data. Figure in Appendix 3 show the source code for transmit and receive 1 byte of data. However, this method is not a good method to be used for wireless communication. This is because the receiver module used will not recognize which transmitter is transmitting data and it will receive all the data to compare within the same frequency. Hence if there is another transmitter with a same frequency transmitting a data ‘3’, the receiver will also take it as true data. Besides, noise at the receiver will also cause this error to happen. For 8-bit transmission, 255 is maximum value. Probability for getting same set of signal from other transmitter: For transfer 1 byte data: The probability is high if the transmission baud rate is taking into account which is in Kilo bit per second. 3.5.6.2 Transmit and Receive with 9th bit as Parity bit. Seem by transmit and receive 1 byte of data is not secured. 9-bit transmission is used. The 9th bit is used as a parity bit to let the receiver confirms that the data receive is correct. A parity bit is used to provide error checking for a single bit error. Figure 3.21 shows that how the data is transfer with a parity bit. From the figure, it is clear that the parity bit will be send before the stop bit is send.

Figure 3.22 Parity bit is send before stop bit 45

In order to used a 9-bit transmission. The 9 bit enable bit in TXSTA and RCSTA have to be enable. When transmit a 9 bit data, the 9th bit data is store in TX9D (refer to figure 1.3) and for receiving 9 bit data, the 9th bit is store in RX9D (refer to figure 1.7). To read a 9 bit data receive, first must read the 9th bit 1st or else the data in RX9D will be lost. The parity bit can be calculated as shown in the figure 3.22 and 3.24 The formula for calculating parity bit has to be program in both the transmitter and receiver side. Before a data is send, the data is first calculate for the parity bit then the parity bit is send through TX9D while the data send through TXREG. When a 9 bit data is receives, the parity bit in RX9D will be store in a file first. Then the data in RCREG will calculated with the same formula as in the transmitter. The last bit of the result after calculations is compared with the parity bit receive. If there are the same then it is true.

Figure 3.23: Illustration Calculating Parity Bit

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Figure 3.24: Sample code for calculating parity bit The advantage of using parity bits is that random number can be transmited without the need to preset at the receiver side. The only thing that need to do with receiver sit is that the formula for calculating parity bit need to be set in the receiving site to let it able to calculate the data receive and compare with the parity bit. An 8 bit data shown above will go through the formula and less significant bit will be the parity bit and send to the receiver through 9XD. However, instability is found in using only 1 parity bit. Many numbers from 0-255 will have the same parity bit after calculate with the formula shown in figure 3.22. When the receiver is off, the transmitter still receives many noise data which will also give a correct parity bit. Hence many errors occur using this method of transmission. Figure in appendix 3 show the source code using parity bit.

3.5.6.3 Transmit and Receive 2 byte data Seem that transmit and receive 1 byte of data is not secure enough. Sending two byte of data is being used. The data being choose to send is first pre set and store in the receiver part. Then in the transmission part, the transmitter will first transmit 1st byte of data then follow a second byte of data. Only if the data being received at the receiver is the same sequence as the pre set data then it is consider as a correct data receive. For example transmit two bytes of data which are 9 and 2. First the transmitter will transfer 9 and then follow by the number two.

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In the receiver part, the receiver will first check is it the first number receive is 9 and if it is correct then it will proceed to check is it the next number receive is number 2. This is something like creating a protocol in the wireless communication. Only if the first step is correct then it will proceed to the next identification step and execute the program if the next identification step is being fulfilled. Figure in appendix 3 (Source code for transmit and receive 2 byte data) shows the source code transmitting and receiving two byte of data. For 8-bit transmission, 255 is maximum value. Probability for getting same set of signal from other transmitter: For transfer 2 byte data: The probability shows that this method is more reliable. After testing with this method, it also found that the stability is much higher than the other two methods. In this project, the wireless communication is sending and receives 2 byte of data.

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3.6

Circuit Casing

Preface: The development of the casing can never be referred as the “easy” part of the design. Having the restriction of not having high-tech machinery equipment had left us with only one option: handmade. This proves to a major handicap for the team as we are dealing with one of the most complex customer demand which is the reliability of the device in terms of shock and water resistance. A casing is used for both the electronic dog collar and the wireless controller unit circuit. In this area, we will describe the design architecture for both casings separately. 3.6.1 Electronic Dog Collar Casing In order to accommodate two independent circuit that is joined together to complete the electronic dog collar circuit, a casing with at least (taking the limitation of being handmade) 13 cm in length x 9 cm in width x 4 cm in thickness is needed. Aside from the circuits, the casing must also have the enough room to place two AA batteries and one 9V battery in it. After looking for the best way to get this casing done, we have chosen to look for a casing with the nearest dimension to our target and modify it to suit our purpose. The casing that we have obtained is a general mini toolbox with partition with the dimension of 13 cm in length x 8.5 cm in width x 3.5 cm in thickness. The material type is a general plastic found in most low cost appliances. It is definitely a water proof material and it is very suitable for our application. The actual casing is then modified by removing the existing partition in it. Then, the casing is cleaned and made sure that the inner side of it is ready for the circuit to be installed. A partition is made to divide the area for the battery and for the circuit. The purpose of this method is so that the end user will never feel any unpleasant feeling (so much of a hassle and untidy looking) when conducting with the device.

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Figure 3.25: The first look of the modified casing

Figure 3.26: The blueprint of the initial proposed casing 50

When the finite dimension is known, the design of the circuit placing is made. This requires delicate attention to make sure that there is enough clearance for the circuit to fit in and also no short circuit will occur. It is important to note that in doing this area of work, a lot of guesstimates work was involved because it is very difficult to place the circuit within milimeters error margin. Many of the measurements taken are directly using ‘observe and measure method’ because using the precise calculation method will eventually lead to different case during actual installation. Therefore the installation was done with the intention just so that the circuit is placed inside safe fully, no short circuit occurs, and that it is refrained from shock and water exposure. The design is then documented in professional drawing software such as the autoCAD.

Figure 3.27: The blueprint of the final component placing

51

As for the installation part, we have chosen to use a 1mm screws to tighten the circuit to the casing body and the EPOXY glue to seal the edge of the casing. The usage of EPOXY glue is that because it is very suitable to ensure the structural strength of the casing as well as maintaining a water resistance casing. Holes were drilled to give a clearance for the L.E.D, the output terminals, and the antenna. These holes were also covered with EPOXY glue to maintain a water resistance casing. Next, the components inside the casing are removed to paint the casing in a finishing black. Finally, all the components are reinstalled properly into the painted casing.

Figure 3.28: EPOXY glue used to maintain water resistance (left), Applying the EDC circuit into the casing (right).

Figure 3.29: Finalized electronic dog collar casing 52

Wireless controller unit casing Insulating Material: Insulation is considered to be anything that will retard the flow of heat. There are a large number of substances that have been used for insulation in refrigerators. Another insulation material is expanded polystyrene. Expanded polystyrene is produced from a mixture of about 90-95% polystyrene and 5-10% gaseous blowing agent, most commonly pentane or carbon dioxide. It is light in weight, easily worked, and is manufactured in various form and shapes. Therefore, it makes a useful insulating material for use in thin-walled refrigerators (Langley, 1990). Expanded polystyrene is selected as the insulation material for the base of circuit. Insulating part is a very important part in this project. Thus, we are very concern about the insulating part. Insulating part helps to block the base of the circuit from the temperature (outside the box). To achieve this objective, we decided to use polystyrene as our insulating material. We used polystyrene to grip the circuit moving from the position. This is because the polystyrene able to control the transmitter circuit from shake and hold it still on its position. The thermal conductivity of polystyrene is as low as 0.035 W/mK. This low value means that polystyrene can works as a very good insulating material. Comparing to other insulating materials such as fiberglass (0.03 W/mK), foam (0.04 W/mK), wood (0.04 W/mK), wool (0.045 W/mK, polystyrene is better choosing. After that, plastics (0.23 W/mK) is better choosing for do the box casing. After considering the budget and limited time of the project, the plastic is the best choose as it is cheap and easily found. The used of plastic and the polystyrene helps to keep the temperature inside the transmitter circuit to cool or hot, shake and hold it still on its position. 53

Besides that, polystyrene also is very low reactive to chemical reaction. The polystyrene is hardly reacts to chemical and temperature changes. The polystyrene actually is a hard, highly transparent polymer built by styrene which empirical formula is CH2=CH–C6H5. The polystyrene is readily formed into beads. These foams and beads are excellent thermal insulators and are used to produce home insulation and containers for hot foods. Styrofoam is a trade name for foamed polystyrene. When rubber is dissolved in styrene before it is polymerized, the polystyrene produced is much more impact resistant. This type of polystyrene is used extensively in home appliances, such as the interior of refrigerators and air conditioner housing. Thus, it is safe to store products such as food or medicines inside the chamber. However, Plastics are typically polymers of high molecular weight, and may contain other substances to improve performance and reduce costs. The first plastic based on a synthetic polymer was made from phenol and formaldehyde. The plastic is insulating shellac to coat wires in electric motors and generators. He found that mixtures of phenol (C6H5OH) and formaldehyde (HCOH) formed a sticky mass when mixed together and heated, and the mass became extremely hard if allowed to cool. Thus it is investigations and found that the material could be mixed with wood flour, asbestos, or slate dust to create "composite" materials with different properties. Most of these compositions were strong and fire resistant. The only problem was that the material tended to foam during synthesis, and the resulting product was of unacceptable quality. Polystyrene is used to build the base and upper the transmitter circuit chamber by the dimension of 6cm x 2cm x 7cm to store our circuit. Thus, plastic is used to build the box or casing by the dimension 6cm x 2cm x 10cm. The small size of plastic (casing) and polystyrene chamber is being designed to fulfill the costumers’ request. Moreover, the small size of casing is easy to travel with and suitable to place at anywhere. Thus, it achieves the objective to make it portable and easy to shock the dog. 54

We have used plastic as a casing by dimension 6cm x 2cm x 10cm of to store our products or circuit. The Figure below shows the dimension and the different parts of the box.

5cm LED

0.7cm

2cm

0.7cm

3cm 10cm

Push Button

2cm

6cm Box specification

Push Button switch

Aerial

Figure 3.30: 3 Dimensional view of the controller unit circuit

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Circuit (inside box)

Battery compartment

Figure shows that the box contains 2 parts, one is the battery hole and the other one is circuit of transmitter. The battery hole is used to store the power supply. Meanwhile the circuit part is stored electronics components such as transformers, circuit board, and controller. There are 3 LEDs at the front side of this product shows the circuit is function or not. The red color is for power supply, green color for low voltage, and orange color for high voltage. Why do we need to produce a casing for Electronic Dog Collar (EDC) remote control. 

Easy to transmit signal



Circuit protection



Easy to touch or use

How do the produce remote control casing.  Analyze the circuit, length and width, and weight.  Search for suitable material that feeds the casing

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Requirement: -

Waterproof

-

Cheap material

-

Durable means since are dealing with dog. So, it is necessary to find and use a durable material which can protect the circuit inside it.



Buy material to make casing



Decide and arrange where to place the circuit and power supply.



Drill tiny holes to accommodate switch and LED on the casing surface.



Put circuit into the casing to test whether the switches and LED fit the holes.



Decide and drill holes or aerial.



Spray casing to black color.



Place the aerial straw on the drilled hole.



Put the company sticker on top of the remote control circuit.

This project use the Solid Work 2008 software for show how the prototype of product of Primetech Electronics.

The prototype is intended for use to shown Primetech Electronics product prototype to client. Figure below show about the all dimensions of the prototype. All dimension in the prototype images are in millimeter (mm).

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The different view of this product:

Front View

Figure 3.31: Front view

Top View

Figure 3.32: Top view

Right View 58

Figure 3.33: Right view

3 Dimensional Views

Figure 3.34: 3 Dimensional views

Remote control of the prototype

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Front View

Figure 3.35: Front view

Top View

Figure 3.36: Top view

Right View 60

Figure 3.37: Right view 3 Dimension View

Figure 3.38: 3 Dimension view

Back view 61

Figure 3.39: Back view

Figure 3.40: Finalized controller unit casing

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Chapter 4 Test data with proof of functional design In this chapter, we include the in-depth analysis of the working electronic dog collar and the wireless controller unit. 4.1 Concept of Electronic dog collar The concept of an electronic dog color is using low dc voltage (3Vdc) to generate a high controllable dc voltage (1000dc). There are many ways to do it. Solution 1 3Vdc > Inverter > Multiplier > 1000Vdc Solution 2 3Vdc > Inverter (using microcontroller) > Transformer > Multiplier > 1000Vdc Solution 3 3Vdc > Inverter > Transformer > converter > 1000Vdc Solution 4 3Vdc > Inverter >Transformer > Multiplier > 1000Vdc (Preferred)

In this project, transformer and multiplier (solution 4) are going to use. Before talking the idea of electronic dog color, that is one important thing that have to mention which is the form of voltage (ac or dc), it will decide the sequence of component which going to use

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4.1.1 Inverter An inverter is an electrical or electro-mechanical device that converts direct current (DC) to alternating current (AC); the resulting AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control circuits. Static inverters have no moving parts and are used in a wide range of applications, from small switching power supplies in computers, to large electric utility high-voltage direct current applications that transport bulk power. Inverters are commonly used to supply AC power from DC sources such as solar panels or batteries. The electrical inverter is a high-power electronic oscillator. It is so named because early mechanical AC to DC converters was made to work in reverse, and thus was "inverted", to convert DC to AC. The inverter performs the opposite function of a rectifier. Inverter is important component in this project; this is because any step-up or step-down voltage component the input must in ac form, in example transformer and multiplier. There are many type of inverter, in example like current-source inverters, variable dc-link inverter, boost inverter and buck-boost inverter. In this project, transistor (BJT) is chosen as inverter (oscillator) so that can activate transformer for step-up voltage purpose.

Figure 4.1: H-bridge inverter circuit with transistor switches and anti-parallel diodes

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4.1.2 Transformer A transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors — the transformer's coils or "windings". Except for air-core transformers, the conductors are commonly wound around a single iron-rich core, or around separate but magnetically-coupled cores. A varying current in the first or "primary" winding creates a varying magnetic field in the core (or cores) of the transformer. This varying magnetic field induces a varying electromotive force (EMF) or "voltage" in the "secondary" winding. This effect is called mutual induction. If a load is connected to the secondary, an electric current will flow in the secondary winding and electrical energy will flow from the primary circuit through the transformer to the load. In an ideal transformer, the induced voltage in the secondary winding (VS) is in proportion to the primary voltage (VP), and is given by the ratio of the number of turns in the secondary to the number of turns in the primary as follows:

By appropriate selection of the ratio of turns, a transformer thus allows an alternating current (AC) voltage to be "stepped up" by making NS greater than NP, or "stepped down" by making NS less than NP. Transformers come in a range of sizes from a thumbnail-sized coupling transformer hidden inside a stage microphone to huge units weighing hundreds of tons used to interconnect portions of national power grids. All operate with the same basic principles, although the range of designs is wide. While new technologies have eliminated the need for transformers in some electronic circuits, transformers are still found in nearly all electronic devices designed for household ("mains") voltage. Transformers are essential for high voltage power transmission, which makes long distance transmission economically practical.

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The transformer is based on two principles: firstly, that an electric current can produce a magnetic field (electromagnetism) and secondly that a changing magnetic field within a coil of wire induces a voltage across the ends of the coil (electromagnetic induction). Changing the current in the primary coil changes the magnitude of the applied magnetic field. The changing magnetic flux extends to the secondary coil where a voltage is induced across its ends.

Figure 4.2: An ideal step-down transformer showing magnetic flux in the core.

A simplified transformer design is shown above. A current passing through the primary coil creates a magnetic field. The primary and secondary coils are wrapped around a core of very high magnetic permeability, such as iron; this ensures that most of the magnetic field lines produced by the primary current are within the iron and pass through the secondary coil as well as the primary coil.

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4.1.3 Induction law

The voltage induced across the secondary coil may be calculated from Faraday's law of induction, which states that:

Where VS is the instantaneous voltage, NS is the number of turns in the secondary coil and Φ equals the magnetic flux through one turn of the coil. If the turns of the coil are oriented perpendicular to the magnetic field lines, the flux is the product of the magnetic field strength B and the area A through which it cuts. The area is constant, being equal to the cross-sectional area of the transformer core, whereas the magnetic field varies with time according to the excitation of the primary. Since the same magnetic flux passes through both the primary and secondary coils in an ideal transformer, the instantaneous voltage across the primary winding equals

Taking the ratio of the two equations for VS and VP gives the basic equation for stepping up or stepping down the voltage

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4.1.4 Ideal power equation

Figure 4.3: The ideal transformer as a circuit element

If the secondary coil is attached to a load that allows current to flow, electrical power is transmitted from the primary circuit to the secondary circuit. Ideally, the transformer is perfectly efficient; all the incoming energy is transformed from the primary circuit to the magnetic field and into the secondary circuit. If this condition is met, the incoming electric power must equal the outgoing power.

Pincoming = IPVP = Poutgoing = ISVS

Giving the ideal transformer equation

If the voltage is increased (stepped up) (VS > VP), then the current is decreased (stepped down) (IS < IP) by the same factor. Transformers are efficient so this formula is a reasonable approximation.

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The impedance in one circuit is transformed by the square of the turns ratio. For example, if an impedance ZS is attached across the terminals of the secondary coil, it appears to the primary

circuit to have an impedance of

. This relationship is reciprocal, so that the

impedance ZP of the primary circuit appears to the secondary to be

.

4.1.5 Weakness of transformer in this project

Even though transformer can step-up voltage but the output are depend to the turn ratio, which is fix by manufacture. This weakness cause the output dc voltage cannot be controllable to reach desire voltage level. To overcome this problem voltage multiplier is selected.

From frequency view point, transformer cannot work in low frequency range this is because, if the rate of cutting magnetic flux too slows (low frequency) transformer cannot be drive. (Voltage is direct proportional to frequency)

4.1.6 Voltage multiplier

A voltage multiplier is an electrical circuit that converts AC electrical power from a lower voltage to a higher DC voltage by means of capacitors and diodes combined into a network. Voltage multipliers can be used to generate bias voltages of a few volts or tens of volts or millions of volts for purposes such as high-energy physics experiments and lightning safety testing. The most common type of voltage multiplier is the half-wave series multiplier, also called the Villard cascade (but actually invented by Heinrich Greinacher).

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Figure 4.4: Villard cascade voltage multiplier.

Voltage multiplier can multiply the input ac voltage to output dc voltage by any integer number like 1, 2, 3, 4…..by changing the arrangement of diode-capacitor pair (Shown in Figure 1 to 4 below)

Figure 4.5: Output dc voltage is 1 time Vin (input ac voltage)

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Figure 4.6: Output dc voltage is 2 times Vin (input ac voltage)

Figure 4.7: Output dc voltage is 3 times Vin (input ac voltage)

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Figure 4.8: Output dc voltage is 4 times Vin (input ac voltage)

By changing the diode-capacitor pair, the level of output dc voltage can be step-up.

4.1.7 Weakness of voltage multiplier

Voltage multiplier only step-up voltage to any higher level voltage (controllable), but still cannot get desire output dc voltage level unless using voltage divider method. From frequency view point, voltage multiplier cannot work in high frequency range this is because charging time of capacitor cannot too short (high frequency).

4.1.8 Overview of project (electronic dog collar)

Inverter = dc to ac

Transformer =ac to ac

Multiplier = ac to dc

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Figure 4.9: Overview of Electronic dog collar

4.2 Operation of electronic dog collar To make transformer function, first the input voltage must be in ac form. So to make dc voltage to ac voltage an inverter is require. In this design project, transistor (BJT) is use as inverter (oscillator). Figure below shown that simple concept how BJT been use as oscillator.

Figure 4.10: Primary side of the tasser circuit 73

Imagine L1 is primary coil in transformer. When Vdc is apply current from battery is going though L2 not L1 due to saturation mode (off) of BJT, Q1. When Voltage L2 reach to certain level BJT will become cutoff mode (on) then the current will flow from battery to L1 coil. Reminder, when L2 is conducting, L1 is going to discharge. Figure below shown that the voltage waveform at L1 coil.

Figure 4.11: Waveform output 1 f = 5000Hz when Battery voltage = 2.7V Table below shown that the result of Primary voltage,Vp (voltage at L1 coil). Table 4.1 Primary voltage Battery Voltage, V

Primary rms voltage, V

3.0

5.50

2.7

5.21

2.6

5.21

(Vp dc = 0V) f = 5000Hz when Battery voltage = 2.7V

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In this design project, the BJT only can function in two mode only which is saturation and cutoff mode this is because base-collector junction and base-emitter junction is always in same bias (forward-forward, backward-backward). Changing the value of resistor does not change the BJT to active mode; the only changing is BJT on-off switching time (frequency of transformer). When the inverter (oscillator) part is solved then transformer can apply to step-up voltage. In this design project a 50 turn ratio of transformer is used Figure below shows the circuit diagram consisting BJT and transformer.

Figure 4.12: Circuit consisting BJT and transformer The secondary voltage waveform is same as primary voltage waveform the only different is the magnitude of the waveform. Figure below shown that the secondary voltage waveform:

Figure 4.13: Secondary voltage output waveform 75

f = 5000Hz when Battery voltage = 2.7V Table below shown that the result of Secondary Voltage,Vs Table 4.2: Secondary voltage Battery Voltage,V

Primary rms Voltage,V

Secondary rms Voltage, V

3.0

5.50

270.81

2.7

5.21

239.48

2.6

5.17

230.41

(Vs dc = 0) f = 5000Hz when Battery voltage is 2.7V From the table, since the secondary voltage is not high enough and also in ac form so a 2 time multiplier is going to use. Figure below shown that the final circuit diagram

Figure 4.14: Tasser circuit

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Figure below shown that the waveform of output voltage,Vo

Figure 4.15: Output waveform of the tasser circuit f = 5000Hz when Battery voltage = 2.7V Table below shown that the output voltage at different battery voltage level Table 4.3: Output voltage at different battery voltage level Battery voltage, V

Vo rms, V

Vo dc,V

3.0

23.19

995

2.7

15.12

660

2.6

14.29

610

From the result above the maximum voltage is 1018.19V (23.19+995).

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4.2.1 Why Vo rms is so low compare to Vo dc? Multiplier is one type of rectifier so that all ac voltage converts to dc voltage. Theoretically Vo rms is zero (ignore) due to capacitor because capacitor filter the ac voltage. 4.2.2 How to measure output voltage Seem the output voltage is so high that is no way direct measure from the output using multimeter so voltage divided method is chosen. Two type of resistor are chosen which is 1.5M ohm, 10% and 51K ohm, 10%. Two pair load are make which is 1.5M ohm- 1.5M ohm pair and 1.5M ohm-51K ohm pair. Using Multimeter, set Vdc to measure the output voltage. Result shown in table below (battery voltage = 3V) Table 4.4: Output voltage measurements result Load 1.5M

R1,ohm ohm- 1.5M

R2,ohm

V(R2),V

Vo,V

1.5M

495.0

Vo=2V(R2)

1.5M ohm 1.5M ohm-

=990 1.5M

51K ohm

51K

34.0

Vo=29.41 V(R2) =1000

Mean of Vo= 995V The result above also testing by oscilloscope and the Vo is approximate 990V. About the Vo rms is calculate from the oscilloscope.

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4.2.2.1 Ideal operation In ideal operation, Vp= battery voltage = 3V Vs= 50 Vp = 150V Vo=2Vs = 300V Percentage of error = [(995 – 300)/ 300] X 100% = 231.67% The percentage of error is too big due to: 1) In ideal operation the initial value of coil is assume zero 2) The error come from instrument 3) The tolerant value of resister 4) In ideal operation, a lot of assumption is make In this project, the electronic dog collar can generate two different voltage there is three way to do it , method 1) Control input voltage using resistor, Rin (prefer) 2) Add or deduce diode-capacitor pair in multiplier 3) Control output voltage using voltage divided method 4) Using feed back system to control Rin Each method has advantage and disadvantage, method 1) Can get any different of output voltage (<1000V) but it will change the frequency of BJT and transformer. 2) Is easy way but just can control certain level of output voltage 79

3) Can get any different of output (< 1000V) but also make a lot of power loss 4) Can get any different of output (<1000V) but have to choose proper respond time

Figure below shows the circuit diagram with Rin

Figure 4.16: Rin application

Table below shown that the result of output voltage with different value of Rin

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Table 4.5: Output voltage with different Rin value

The Rin value just stop at 8.2 ohm because when Rin value up to 16 ohm the output voltage almost become zero and that is no point for generate low voltage. From the table above, the conclusion is Rin increase Vo decrease

4.2.2.2 Current drawn from battery when open circuit and short circuit

Battery life time is depend to the how circuit consume current at load side(output). The table below shown that the current drawn from battery with different Rin value

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Table 4.6: Current drawn from battery with different Rin value

Io= open circuit current, Is= short circuit current

From the table above, the conclusion is

1) battery voltage high the more current draw from battery 2) Rin low the more current draw from battery

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4.2.2.3 Relation between R (Rin + R1) and frequency

Figure 4.17: R (Rin + R1) and frequency relation

Observe from oscilloscope, value R increase frequency also increase. Mention before when frequency too low transformer cannot be drive because voltage is direct proportional to frequency. When frequency is too high there is no enough time for charging in multiplier, it will affect the output voltage. The project is function when R (Rin + R1) is in 470 to 478.2 ohm (observed from oscilloscope).

Why R affect frequency

To make it easy, assume voltage at L2 coil reach certain value the BJT switch will trigger.

L di/dt = V, therefore di/dt = constant

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When di become small due to R (Rin + R1), dt also become small (dt = f). So when R increase frequency also increase.

Modifying electronic dog collar

Modifying is needed so that to improve the circuit becomes more safety and more users friendly. The figure below shown that some modifying in this project

Figure 4.18: Modified electronic dog collar circuit

From the figure above a LED is added shown in ‘A’, the purpose for adding LED is let user know that the electronic dog collar is in ready-mode, ready for training. Another modifying is add one resistor at the output side shown in ‘B’, the purpose for adding resistor is to discharge the charge store inside the capacitor, this is important and also for safety purpose because when dog trainer take out dog collar from dog and user miss-press the remote control button it will not generate voltage for next short circuit.

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4.3 Testing on wireless communication 4.3.1 Testing RF-Module A testing RF- Receiver circuit is build to test the receive signal. The schematic of the testing circuit is shown in figure 4.19 below.

Figure 4.19: Schematic of testing circuit for receiver.

There are 8 LED as indicator of the receive data is connected in port B of PIC16f877A. Once data is receive by the receiver, the receive data will move to show in port B. There are 8 LED because the data receive is in 8 bit and each LED represent each bit of the data. Hence the Data receive is in binary form can be convert manually to base 10 number.

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4.3.2 Determine how the receiver is interfere by other transmitter with same frequency. Due to the receiver circuit shown in figure 3.11 will be interfere whenever there is other transmitter with same frequency transmitting data, the testing circuit shown in figure 4.19 is used to determine the how the other transmitter will interfere the receiver when two transmitter is transmitting. The experiment is conduct as explain below: Procedure: 1. One of the transmitters is programmed to send a digit 80, which is 01010000 in binary continuously. 2. The other transmitter is programmed to send digit 55, which is 00110111 in binary continuously. 3. The data receive by the testing receiver circuit is being recorded. 4. Table below shows the result obtain from the receiver. Table 4.7: results for testing inference Data receive by the receiver in binary form

Data receive convert to base 10

10001001

137

11100101

229

01010011

83

10010011

147

00010101

21

00100101

37

11100100

228

00101001

41

00101011

43

Analysis From the result obtain above, it can be prove that the interference does not stop the receiver to receive data. However, it hardly receive a correct data transmit form either of the transmitter which is either 80 or 55.

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Discussion The transmitter transmits data bit by bit from the less significant bit to most significant bit. Same thing goes to the receiver where the first bit it receives is the less significant bit and the last bit receives is the most significant bit. Figure 4.20 show the data was transmitted and received bit by bit. From Transmitter

To Receiver Figure 4.20 Data is Transmit and Receive Bit by Bit Hence, the 1 byte data receive by the receiver is not exactly the 1 byte data from a single transmitter if there is more than one transmitter transmitting data. The 8 bit data receive is come separately from the different transmitter which causes the failure for the receiver to receive data. Figure 4.21 illustrate the error occur when there is interference.

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Figure 4.21: illustrate the error occur when there is interference However, this type of error cannot solve by either software or hardware. As long as the frequencies of the transmitters are the same, it will interfere with the receiving process. If two transmitters are used, when the transmitter is not transmitting data, the supply source to the transmitter has to be cut off to prevent this type of interference. The method use to cut off the source is discussed in section. Conclusion: Although the interference discussed in this section cannot by avoid by either software or hardware but the error data will not execute the program. Which mean that even though there is interference, with the 2 byte sending method, the electronic dog collar will not shock the dog when error data was received. 4.3.3 Determine The Range of The Wireless Remote Control Another experiment is conducted to test the range of the RF remote control range. This experiment is conducted in SKTM block C, Makmal Electronic Asas. Three condition is being tested. These conditions are:

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1) Transmitter and receiver without antenna, 2) Transmitter and receiver with antenna but the receiver is left in the room while the transmitter is outside the room. 3) Transmitter and receiver with antenna. Both the transmitter and receiver are tested in an open surrounding. Test Result Table 4.7: Experimental result of the range of the RF remote control in different condition Condition

Outcome

1

Receive Range less than 5 meters

2

Receive range about 25 meters

3

Receive range about 35 meters

Conclusion: Seem the dog training is run in an open air surrounding, the range of 35 meters is more than enough for using this electronic dog collar for training purpose.

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Chapter 5

Final cost, schedule, summary and conclusions Final expenses - List of initial Components had been bought Item

Unit Price

Quantity

Total

Ac-Dc Power Supply

RM18.00

1

Rm18.00

PIC16F877A

RM30.00

2

RM60.00

RF Transmitter

RM35.00

1

RM25.00

RF Receiver 433Mhz

RM25.00

1

RM35.00

Capacitor 0.03uF

RM3.00

1

RM3.00

Capacitor 0.03uF 800V

RM2.70

1

RM2.70

Transformer

RM5.00

1

RM5.00

Transistor 3904

RM0.50

5

RM2.50

Transistor cs8050

RM0.50

1

RM0.50

Potential Meter 1M

RM3.00

1

RM3.00

Zener Diode 10V

RM0.70

2

RM1.40

Zener Diode 20V

RM0.70

2

RM1.40

433Mhz

1000V

ohm

90

Diode ln4007

RM0.30

2

RM0.60

Zener Diode 12V

RM0.70

2

RM1.40

Resistor 10k ohm

RM0.20

3

RM0.60

Resistor 10M ohm

RM0.30

2

RM0.60

Resistor 470 ohm

RM0.20

1

RM0.20

Resistor 820 ohm

RM0.20

1

Rm0.20

Toggle Switch

RM1.50

2

RM3.00

Push Button

RM4.00

10

RM4.00

Crystal 20Mhz

RM2.50

2

RM5.00

Capacitor 100uF 25V

RM0.40

4

RM1.60

5V Voltage Regulator

RM1.50

3

4.50

RM0.20

10

RM2.00

RM0.20

10

RM2.00

Relay 5v

RM1.50

1

RM1.50

LED

RM0.20

10

RM2.00

7805 Resistor 330 ohm 0.25w Resistor 4.7k ohm 0.25w

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TOTAL

RM186.70

Additional components bought Toggle switch

RM1.30

1

RM1.30

Push On Switch

RM0.70

3

RM2.10

Transformer

RM10.00

4

RM40.00

Transistor

RM0.50

3

RM1.50

TOTAL

RM44.90

PCB development - pcb printing

RM4.00

- pcb board X 2

RM34.00

- soldering lit

RM2.00

Report and other tasks printing

RM45.00

Power supply (batteries) 9V X 2

RM 11.00

Casing development -casing container

RM9.60

-cotton buds

RM0.90

-Toa spray stand 400ml

RM6.50

-abrasive paper cw500

RM1.20

TOTAL

RM114.20

ALL TOTAL

RM345.80 92

Final Gantt chart Several differences can be seen in the final Gantt chart. The most significant is the last five plans which had been postponed until the last week of April. This is caused by the PCB development which has been postponed. Two other parts which were obvious was the building and testing on circuit designs on bread board research and determining wireless circuit for remote control. Building and testing circuit design on bread board took a long time to be settled since the team were facing some problems to produce certain desired values of output voltage.

Figure 5.1: Final Gannt-Chart

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Summary Electronic dog collar can be really sells in the market. In Malaysia, there is still no dog training collar as such. Electronic dog collar can be very useful to the dog breeders especially in training their dogs. The electronic dog collar circuit had been built successfully. Although after transferring it to the photo resist board, it did not function well, but it was functioned successfully on the bread board when tested in the beginning. There were several failures which we did not achieve. First, is the three values of output voltages which indicate the pain felt by the dog. Initially Primetech Electronics proposed to produce three ranges of output voltages. This is designed to fit the dog’s needs and ability to stand the pain. Small output voltage is designed for puppies and the largest output voltage value is designed for big dogs and which are quite wild and fierce. Feedback circuit is applied as a solution for this problem, before it was found that feedback is not suitable to be applied in the circuit although it is theoretically is to solve this problem. Another failure was to produce as small electronic dog collar as possible could not be done. Comparing the size of electronic dog collar which is available in the internet market, our product is quite big. For some reason, our product might be fit for moderate to larger dog size. This is due to the circuit size and the material which was used to produce the casing. The third failure was to produce a jack to recharge the batteries. It is known from earlier that electronic dog collar utilised the power supplied very fast. Initially Primetech Electronics intended to produce an electronic dog collar which can recharge the rechargeable batteries without removing the batteries but failed.

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This is due to very limited time duration given to do this project. Some suggestions were made for people who are interested to do this project in the future. First, do lots of research about the circuit, how to produce, how the circuit function and so on. Meeting and ask for dog breeder’s opinion is very crucial. There is a lot of information that can be taken from it. A dog breeder knows best dog behaviour, what does it afraid of, how it will react and others. This discussion can lead to a successful product-making. Then, a team should been doing the PCB earlier so trouble shooting can be done several times to inspect which part that went wrong. The length of PCB should be maintained (2.5-3.2 inches) but the width should be decrease. This is to make the electronic dog collar suit to any dog size. Conclusion The initial idea that was to build an electronic dog collar circuit based on a tasser circuit was finally achieved. Team Primetech Electronics was also able to integrate the electronic collar with a wireless function and thus making it more interesting. The time limit and budget was followed properly and the device is working within the expectation of the team. With the current result, we at team Primetech Electronics conclude that our project has prevailed despite having uncountable difficulties throughout the entire project.

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Appendix 1 Technical involvement essay Prepared by: Aylmer Alfredo Ambu (Team Director), HK2006-5180 As for starters, I have done some research in finding the basic principal of how to get a working tasser circuit done. This initial work had led my team in finding the best way of building a tasser circuit. Then we as a team have been working to build the sample circuit and tested its effectiveness. I was involved in the testing and am very pleased with the result.

Me doing some testing on the effectiveness of the tasser circuit As the project progress, I have assigned the responsibility of the circuit development of both electronic dog collar and wireless controller unit circuit to my remaining team mates as I felt that there are other necessities in the project that must be look upon. These other necessities include the idea of integrating a rechargeable battery concept to the circuit, casing development and etc. The management of the team was considered to be promising as we have now distributed the work properly among members and set a specific due date for each assignment. At this point, I was concentrating a lot on the casing development and was looking for ideas to make it operational, unique and believable. 96

Next, coming to the circuit build up, I have been working a lot on the development of the casing for the electronic dog collar. Several casing/container types have been explored and finally one was chosen. The selection of material type as well as its size is the main criteria that were look for when choosing. On the design aspect, the positioning of the buttons and switches, output terminals, and the L.E.D was solely done under my supervision alone. This process includes measuring and selecting precise distance of these buttons/switches, output terminals, and the L.E.D so that there will be no problem occurs during installation of the circuit content and the casing. Furthermore, the installation of the completed circuit to the casing body was done by me. This is to ensure that there is no miscommunication between team mates and that the installation proceeds with no issue. Aside from casing, I have also contributed with other duty including the PCB drilling and cutting.

Me doing PCB drilling (left) and casing cutting (right) On the paperwork technical, I have documented the casing design in details in the drawing software autoCAD. To summarize my involvement of the project, I can say that technically, I was dealing more on the casing development compare with other department.

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Prepared by: Isnaraisah Munirah (Team Documentation Manager), HK2006-6598 My technical part in this circuit is the PCB developing as well as the transmitter casing developing. Printed Circuit Board Developing Printed Circuit Board (PCB) is a board where components can be designed according to one’s desires. Different from bread board and the strip board, it is crucial to use a photo resist PCB board to design the electronic dog collar as small as possible. We chose the photo resist PCB board because it is easier compare to the ordinary board which need ‘lattering’ to produce the circuit route and holes. The circuit was first illustrated by using ‘Proteus version 7.4’, software which can simulink circuit and draw PCB. Schematic diagram needed to be drawn from the circuit on the bread board before draw the circuit in ARES ‘Proteus’. One should consider every aspect before draw the PCB. The most important are the component size and the component distance to another component. Several components which needed to be pay attention are the transmitter, receiver, relay and the transformer. After finalized the circuit, the PCB layout should be printed using a laser printer. Then the PCB real development begins. The first step was to paste the PCB layout which has been printed on the tracing paper. It is then put in a special ultra-machine to produce the layout on the photo resist board fro about six minutes. Later, the PCB board is etch in a container which contains liquid acid which will peel the photo resist layer for the first process for 15minutes. Then the second peeling was to peel the cooper from the board for 15 minutes as well. Once the PCB is done, then the board will be drilled first to make holes before soldering. My task was to solder the Receiver circuit.

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Casing Developing

To develop the casing for transmitter, what was needed is to find a suitable box to place the transmitter circuit. The aspect which was needed to be considered are how will the user change the batteries easily and where shall to put the buttons.

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Prepared by: Mohd.Azlan bin Malla (Team Presentation Manager), HK2006-6482

PCB: PCBs are boards where upon electronic circuits have been etched. PCBs are rugged, inexpensive, and can be highly reliable. They require much more layout effort and higher initial cost than either wire-wrapped or point-to-point constructed circuits, but are much cheaper and faster for high-volume production. Much of the electronics industry's PCB design, assembly, and quality control needs are set by standards that are published by the proteus software. Firstly, do the circuit or schematic diagram. Then, circuit is converted to the PCB layout. To produce a PCB layout softwares that can be used are the proteus software and ipc software. Before do the PCB layout, we must measure the length and the width of the components so that the component can be placed accurately on the PCB board. After measure all the component and can do the PCB. Some PCBs have trace layers inside the PCB and are called multi-layer PCBs. After that, before print the PCB layout must convert to adobe reader so that easy to print. Besides that, printing must be in transparent paper. Next, do the ultraviolet the PCB for scan the layers inside the PCB. Then, go to chemical part where the layer will appear on the PCB. This is because for easy to do the etching. After that, etching will do to erase the copper not use in the PCB.

Etching part will take 15 minutes.

After that, the PCB must develop for

decrease the acid. Besides that, we also do the drilling on PCB. The holes through a PCB are typically drilled with tiny drill bits made of solid tungsten carbide. Next step is soldering the component. Areas that should not be soldered to may be covered with a polymer solder resist (solder mask) coating. The solder resist prevents solder from bridging between conductors and thereby creating short circuits. Solder resist also provides some protection from the environment. Finally, test the circuit function or not. If not, troubleshoot the circuit to find the problem the circuit. 100

CASING: -

Besides that, I also do the casing in this project.

1) Draft the casing

2) Casing with color 3) Back view the casing

101

Circuit (inside box)

Battery holder 4) Final casing

Soldering:

-

I also do the soldering.

1) Soldering the component to the PCB

-

After soldering, I transfer the circuit to inside the box 102

Prepared by: Thian Nyuk How (Team Technical Manager), HK2006-3092 Date: 15 April 2009 In this project, I’m in charge in doing the wireless communication which is the wireless remote control and a wireless receiver in the dog collar circuit. In doing this wireless remote control and the wireless receiver in the dog collar circuit, a pair of RF-module which is in 433 MHz is used as the main device of the wireless communication. The software used to interface the RF-module with the microcontroller 16F877A and 16F628A is Universal Synchronous - Asynchronous Receiver Transmitter (USART) which is used as a serial communication for microcontroller. Asynchronous mode is used in this serial communication. Seem in asynchronous mode it does not have a separate clock accompany the data, baud rate generator is used to generate the same baud rate at both side of the transmitter and receiver as started in chapter 3.

Me doing P.I.C programming In order to optimize the performance of the wireless remote control, 3 method of data sending have been try as started in chapter 3 which are transmit and receive 1 byte data, transmit and receive with a 9th bit as parity bit, transmit and receive 2 byte of data. Transmit and receive 1 byte data shows a week security in this wireless remote control system.

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As for the transmission with 9th bit as parity bit, the security is increase with the ability to send random number which means that each time the value used as a data signal is different. However this method is too sensitive to the noise hence it is not suitable to use. However, the uses of two parity bits might be able to increase the performance of the use of 9 bit transmission. Among those 3 methods, the best method is transmitting and receives 2 byte data. Besides doing the wireless communication, I’m also using the analog to digital convertor to do the battery indicator. From the testing result, the battery is week when the voltage of the battery is 2.6volt. At this level of voltage, the LED indicator will on to indicate the battery is week. This battery indicator system is not automatic system. It is a manually operate system where user need to press the test button in order to know the condition of the battery. Two of these task is completed successfully although there’s lot of obstacle faced before reach this stage.

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Prepared by: Lim Kok Leong , HK2006-3141 Testing and collect data from electronic dog collar circuit. In this project I try getting any data which available from circuit. When starting collect data I got problem how to collect ac voltage and dc voltage reading because no familiar using oscilloscope and analog multimeter. When know how to use those measurement tools I try manipulate resister value to see is it resister value will affect the primary voltage, secondary voltage and output voltage and how much it changing. Form data getting I also try to explain relationship between each other (parameters) to improve or come out an alternative solution. In this project I known how to convert ac to dc or dc to ac, I know how frequency affect this circuit. I hope the knowledge what I get from this project can apply to my future. Last, I still got some disappointed about this circuit because I do not know how to expand then frequency bandwidth of this circuit (this circuit have a small frequency bandwidth)

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Appendix 2 http://en.wikipedia.org/wiki/Inverter_(electrical) http://en.wikipedia.org/wiki/Transformer Flanagan, William M. (1993-01-01). Handbook of Transformer Design and Applications. McGraw-Hill Professional. Chap. 1, p. 1–2. Winders. Power Transformer Principles and Applications. pp. 20–21. http://en.wikipedia.org/wiki/Voltage_multiplier Sandra and Smith. Microelectronics. http://www.puppy-training-solutions.com/electronic-dog-collar.html

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Appendix 3 Source code for transmit and receive 1 byte data

Transmitter

Receiver 107

Source code for transmit and receive 9th bit as parity bit

Transmitter

Receiver

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Source code for transmit and receive 2byte data

Figure 2 source code for 2 byte transmission

Transmitter

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Receiver

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