Ece 9 Project Document Ation (final)

I.

Title of the Project

DIGITAL COUNTDOWN TIMER II. Rationale The digital countdown timer device somehow queues with the global competitiveness in the field of high technology. The primary reason of its existence is for convenience of people to life. Basically, it is not designed and created to encourage

people

to

become

lazy,

but

to

help

them

do

multitasking and lessen efforts in dealing things especially today where there is an increasing demand of human attention towards

many

varied

things

caused

by

the

improving

technological trends. A busy person tends to forget the other things he is doing, thus, this project is also designed to address to this particular tasks

problem

because

of

of

any

being

person:

very

busy.

forgetting With

the

about aid

other

of

the

countdown timer device, one just easily sets up an appliance to turn on or off, as desired, in a chosen span of time, therefore, minimizing his efforts in manually turning on or off the appliance.

III. Introduction Description of the Project With the advent of technology, people nowadays think of making their lives convenient.

Everyone wants to make his

life more comfortable by just having everything to be easily accessed.

Answering

to

such

want

of

the

people,

remote-

control has been invented for easy access on appliances or certain electronic and electrical devices. However,

although,

people

have

already

been

provided

with this tool to somehow reduce their efforts in operating appliances,

still,

people

want

more

and

ask

for

more

convenience. The most common problem is that busy people tend to forget

on

turning

off

their

appliances

because

of

the

other tasks they are doing. Hence, this project is designed to respond to the need of a person for a certain device to perform automatic power on or off of some appliances to avoid leaving them operating and consuming electrical power, thus, wasting energy and money too. The invented device, Count Down Timer, is not limited to automatic turning off of appliances but also its reverse. Its application for instance is when a person would want to have an

appliance

operating

after

a

certain

span

of

time.

A

specific example would be when one would want his television to turn on after five minutes expecting his favorite game show will already air.

Review of Related Literature The following review of a related literature is taken from www.quasarelectronics.com. The project is specifically a simple photographic timer. The simple photographic timer is the first of a series of timer kits based on the 3148 hardware platform. This is a simple down timer with selectable preset times. At the end of the selected time period the output goes ‘low’ for 2 seconds.

There are six (6) preset times: 60, 90 120, 300, 600 and 900 seconds (1, 1.5, 2, 5, 10 and 15 minutes). Refer to the “3148 4-DIGIT TIMING MODULE” documentation for

details

of

hardware

features,

circuit

description

assembly instructions.

TIMER SPECIFICATIONS

Timing ranges

60, 90, 120, 300, 600, 900

Timing resolution Inputs

secs 1/10 second Start, Stop and Reset 2 second active low Open

Output

collector NPN transistor,

Display Supply voltage Supply current Physical size Connection

OPERATING INSTRUCTIONS

100mA @ 30V 4-digit 7-segment with decimal point, 14mm RED LED 9 to 12V DC 30 to 50mA, depending on the number displayed. 51mm x 66mm (2.0” x 2.6”) 10-way right-angle SIL header pins, 0.1” spacing

and

The ‘power up’ default time is 60 seconds (the display shows

60.0).

Pressing

the

STOP

button

cycles

through

the

other preset time delays. Pressing the START button starts the timer. The display starts running down towards zero in tenths of a second. When it reaches zero (0.0) the open collector output pulses low for

2

seconds

and

the

timer

then

resets

itself

to

the

selected time delay.

During the count down time, pressing the START button again has no effect. Pressing and holding the STOP button ‘freezes’ the timer at its current value. Releasing the STOP button then resets the timer to the previously selected time delay, ready to start again. At any time the timer can be reset via its RESET input. The timer will reset to the previously selected time, ready to start again.

Applications This

timer

was

developed

after

an

inquiry

from

a

hobbyist who wanted a simple 60 second timer when printing photographs. At the end of 60 seconds a beeper or buzzer would sound to indicate ‘times up’. After some discussion about other photographic uses it was decided to add some extra ranges as well. We also decided on an open collector style output rather than an on-board buzzer. This enabled the kit to drive other devices such as relays, making it more useful in other applications.

Open Collector Output. For more information about what an open

collector

output

is

read

the

FAQ

sheet

at

www.quasarelectronics.com/ds.htm#3148.

Connecting to the Timer A 10-way header strip provides external connection to the timer, including power. All the inputs and the output are organized

as

having

corresponding

a

‘pairs’

of

pins,

with

each

ground

pin,

as

input

per

or

the

output

following

diagram. The ‘+’ sign indicates the actual input or output pin and the ‘-’ sign indicates its associated ground pin.

Note: When using the output to switch a load (relay, buzzer, etc) connect the load between the output pin and a positive DC voltage. For example, if switching a 12V relay connect the relay between the output pin and +12V.

Other Timing Modules There are other firmware IC’s available for 3148: 1. 3148T2. Stopwatch with Pause function 2. 3148T3. 40KHz Auto Ranging Frequency Meter 3.

3148T0. Programmable Down Timer counting down in seconds from a maximum of 10,000 sec

4.

3148T4 Programmable Down Timer counting down in minutes from a max of 10,000 minutes

5.

3148T5 Programmable Down Timer counting down in hours from a maximum of 10,000 hours

IV. Technical Aspect

A.

Detailed

Explanation

of

How

the

Project

Works

/

Operates Digital countdown timer is based on a micro controller, thus securing reliability and excellent operation under any circumstances. It can be programmed to countdown up to 999 minutes and 59 seconds. When the timer starts counting, a relay is activated. When this time reaches zero, the relay is disabled.

This

can

be

used

for

automation

and

wherever

a

reliable timer is needed. The heart of the circuit is a micro controller

from

the

8050

family

manufactured

by

Winbond

Microchip, the W78E51B. The time is displayed by 3 sevensegment displays and it can take any value from 0 to 999 minutes and 59 seconds. Crystal

Y1

along

with

capacitors

C1

and

C2

form

the

circuit that produces the 12 MHz reference signal. As you can easily calculate, the 12 MHz frequency leads to a duty cycle of 1μsec. This means that every command is executed in only 1μsec. The LM7805CV voltage regulator, the D1,D2,D3 and D4 diode and the C1, are supplying the necessary +5 Volts to the micro controller, independent of the input voltage that can vary

from

9

to

15

Volts

DC.

The

capacitor

C2

makes

the

regulator capable of responding to fast changes of the load current, making sure that the circuit will be fed with the proper voltage at any time. Transistor Q1, resistor R1 and diode D5 drive the relay. Transistor Q1 acts like a switch. Diode D5 protects the transistor from the inductive voltage that occurs at the relay terminals every time it’s activated. Resistor R1 limits the base current and is responsible for the switching operation of the transistor. Visualization

of

the

microcontroller’s

output

is

done

through three 7-segments displays. Transistors Q3, Q4, Q5, and resistors R6 to R13 form the network that is driving the displays. These three transistors act as switches driven by the voltage (0 or 5V) that appears at the microcontroller’s pins 1 to 8 that are programmed to operate as outputs. Every time that a transistor is “on” the relevant display is active

and displays the contents of its seven segments (A, B, C, D, E, and F and decimal point). The displays get the data from the IC and display it in decimal mode e.g. numbers from 0 to 9. In order to reduce the communication lines from the IC to the displays from 32 to 12, we have to make sure that when a display is active, the rest two must be set off. This timesharing is an easy job for a device like the W78E5iB. One should expect the brightness of the LEDs to be low using this method of operation, but using the Q3 to Q5 transistors and calculating the value of the R6 to R13 resistors carefully, we achieve the highest brightness possible.

Electrical Specification Supply Voltage: Surge Protection:

220 Volts AC +/- 10%, 60 Hertz, single phase MOV 220V Standard appliances up to 15 Amps

Compatible Load Types:

and incandescent lights up to 800 watts

Power Plug:

2-pin

Controlled Outlet:

2-pin

Minimum Load:

No minimum load required 15 Amps (for resistive loads);

Maximum Load:

800

Watts

(for

incandescent

loads) Device power requirement: PUSHBUTTON OPERATION

9-VDC to 15-VDC

500mA

Programming controls: 2 pushbuttons: Start/Select, Reset S2 Reset •

Reset to zero

•

Start programming

S1 Select/Start (control) •

Set minutes and seconds

•

Set seconds and tenths up to 999 minute.

B.

Parts List

PARTS / COMPONENT

DESCRIPTION W78E51B is an 8- bit microcontroller which can

IC = W78E51B

accommodate

a

wider

frequency

range

with low power consumption. It contains 4k bytes flash EPROM, 128 bytes RAM, & TWO 16-bit timer/counter.

IC = NEC 2561

High Density Mounting Type Photocoupler Transistors

are

tiny

electrical

devices

that they can amplify an electrical signal Q1, Q2 = C1815

and they can switch on and off, letting current

through

or

blocking

it

as

necessary. NPN 0.4 W 60V 0.15A (TO-92) ECB Q3, Q4, Q5 = A1015 Q6 =

LM7805CT

PNP 400mW 50V 150mA 80MHZ (TO-92) ECB Positive Voltage Regulator 1.5A, 5V (TO220)

R1=22k, R2=2.2k, R3 to R5 =1.5k, R6 to R13=130 ohm, R14 to R23=2.2k,

An electronic device use for resisting an

R24 to R25=2.2k,

energy or electron flow

R26=470ohm, R27=10k, R28=4.7k, R29=680ohm 1A 50V (DO-41 plastic) Diode Rectifier. An electronic device with D1, D2, D3, D4, D5

two wires or terminals. A rectifier allows

1N4001

electrical current to flow through in only one direction and is used for converting alternating current into direct current. Electrolytic capacitor is a device that

C1 to C2 =

stores

electrical

1000uF/16V,

positively

C3 = 4.7uF/50V

negatively

charged charged

between them.

charge,

using

a

and

a

a

gap

surface surface

with

Ceramic capacitor is a filter capacitor or

C4 to C5 = 30

condenser,

pF,

the

function

is

to

filter

or

smooth the rectified DC voltage produced by

C6 = 104pF

the rectifier. The crystal is usually quartz, also has a resonant frequency of its own, but optimum

XTAL = 12 MHZ

performance is obtained when it is coupled with an external capacitance.

YT5631BS seven segment

0.8-inch Triple Digit, Seven Segment Display

LED display LED = Red,

Light Emitting Diode (Hi-Bright Diffused 5mm

Green

20mA) Is an electromagnetic relay that is basically

K1 (SPST Reed

electrically-control switch, it consists of a

Relay 12 Volt DC Coil

coil

5A

that

permeable

Mini PCB type)

is

energized

to

magnetize

a

iron

circuit

and

actuate

an

armature.

Miscellaneous / Other Parts: •

Buzzer 12v

•

Push Button Switch

•

Toggle Switch

•

Illuminated Power Rocker Switch / Light

•

Plastic Case

•

Transformer

–

Input

220

volt

/

Output

(Step-down Transformer) •

AC Socket

•

AC Cord with Plug

•

HC872 Plastic Case

•

PCB / Bolts

•

Fuse / Holder (quick active glass tube fuse)

Chassis-mounted

12volt

500mA

C.

Block Diagram

3 SEVEN-SEGMENT LED DISPLAY

PORT LATCH & SEVEN-SEGMENT DRIVERS

OSCILLATOR

8-BIT MICROCONTROLLER SYSTEM

CONTROL & INSTRUCTION REGISTER

D. Schematic Diagram

Detailed Schematic Diagram

E.

PCB Layout

F.

Applicability of the Project

This

project

practicality

can

since

be

this

regarded device

as

is

having

very

a

useful

definite to

the

lifestyle of people nowadays. As to humanity, this project is even considered feasible since we are presently living in a world of comfort through different electronic and computer gadgets, thus, keeping us inattentive to other chores. Since this device is digital in nature, it is also expected that the

timing

is

timer.

Hence,

living

we

nowadays.

accurate this

have

now

compared

project and

is

the

to

a

mechanically-driven

applicable kind

of

to

the

technology

kind we

of

have

V.

Conclusion / Recommendation Given

trials

during

the its

project

above,

construction,

we

encountering have

all

finally

the

concluded

that: 1.

a timer is generally different from a stopwatch because the later counts upward from zero for measuring elapsed time while the former counts down from a specified time interval,

2.

a

digital

timer

mechanical

is

timer

more

since

advantageous digital

than

timers

a

can

achieve higher precision because they are quartz clocks with special electronics, 3.

integrated circuits have made digital logic so inexpensive that an electronic digital timer is now

less

expensive

than

many

mechanical

and

electromechanical timers; individual timers are implemented

as

a

simple

single-chip

computer

system, similar to a watch; watch technology is used in these devices, and 4.

this project really helps busy people to (a) integrate automation in his lifestyle so as to decrease stress in exerting more efforts, (b) do multitasking to save and maximize time, and (c) conduct accurate timings in switching on or off or

in

the

operation

of

certain

electrical

devices.

With

the

above-stated

conclusions,

we,

therefore,

recommend that: 1. this project should be advertised to public for the aim of attracting electronic devices manufacturers to venture on producing the product, and

2. this device should be improved to ensure safety and maximum

use

and

benefit

of

the

product

to

consumers or buyers. VI.

Appendices

A. Data Sheets / Pin Configuration

7 – SEGMENT PIN CONFIGURATION COMMON ANODE CA1

CA2 CA3 A F

B

NC E D CG DP

(Also See Attached for other Pin Configurations)

the

B. Picture of the Project

C. Curriculum Vitae

C

U

R

R

I

C

U

L

U

M

V

I

T

A

JERRY JALA LEPORNIO Age Address Contact Number Citizenship Religious Aff. Birth Date Birth Place Father Mother

: : : : : : : : :

25 P-5 Bilay, Butuan City 09197924325 Filipino Roman Catholic December 31, 1982 Bilay, Butuan City Teodulo Lepornio Arcadia Cabrera Jala

EDUCATION College Degree

: Saint Joseph Institute of Technology Butuan City : BS in Electronics Engineering (BSECE) 4th Year

Secondary

: Bilay National High School Bilay, Butuan City 1998-99

Elementary

: Bilay Elementary School Bilay, Butuan City 1994-95

E

C

U

R

R

I

C

U

L

U

M

V

I

T

A

JOE RANDY BALANSAG TABUNGAO Age Address Contact Number Citizenship Religious Aff. Birth Date Birth Place Father Mother

: : : : : : : : :

20 Alubihid, Buenavista Agusan del Norte 09096656622 Filipino Philippine Catholic (PECC) September 13, 1988 Buenavista Agusan del Norte Jose Jagna Tabungao Judith Hidalgo Balansag

EDUCATION College Degree

: Saint Joseph Institute of Technology Butuan City : BS in Electronics Engineering (BSECE) 4th Year

Secondary

: Buenavista National High School Matabao, Buenavista Agusan del Norte SY 2004-05, 1st Honorable Mention

Elementary

: Saint Joseph Institute of Technology Butuan City SY 2000-01, 3rd Honors

E

C

U

R

R

I

C

U

L

U

M

V

I

T

A

KEITH MARVIN ATEGA DELGADO Age Address Contact Number Citizenship Religious Aff. Birth Date Birth Place Father Mother

: : : : : : : : :

20 Cabadbaran City 09109251746 Filipino UCCP May 19, 1988 Oroquita City Wills Pagasian Delgado Prosperity Mae Badajos Atega

EDUCATION College Degree

: Saint Joseph Institute of Technology Butuan City : BS in Electronics Engineering (BSECE) 4th Year

Secondary

: Mindanao Institute Cabadbaran City SY 2004-05

Elementary

: Sapang Dalaga Elementary School Sapang Dalaga, Misamis Occidental SY 2000-01

E

C

U

R

R

I

C

U

L

U

M

V

I

T

A

VICTOR LABADOR GENZON Age Address Contact Number Citizenship Religious Aff. Birth Date Birth Place Father Mother

: : : : : : : : :

21 Guinabsan, Buenavista Agusan del Norte Filipino Roman Catholic Godofredo Genzon Guinabsan, Buenavista Agusan del Norte Godofredo Genzon Concordia Labador

EDUCATION College Degree

: Saint Joseph Institute of Technology Butuan City : BS in Computer Engineering (BSCpE) 4th Year

Secondary

: Guinabsan National High School Guinabsan, Buenavista Agusan del Norte SY 2004-05

Elementary

: Lumboyan Elementary School Guinabsan, Buenavista Agusan del Norte SY 2000-01

E

C

U

R

R

I

C

U

L

U

M

V

I

T

A

CYRUS YAO CABALLES Age Address Contact Number Citizenship Religious Aff. Birth Date Birth Place Father Mother

: : : : : : : : :

19 P-2, B-3 San Francisco Agusan del Sur 09104980638 Filipino Roman Catholic January 8, 1989 San Francisco Agusan del Sur Cesar Concerman Caballes Sr. Virgilia Mabulay Yao

EDUCATION College Degree

: Saint Joseph Institute of Technology Butuan City : BS in Computer Engineering (BSCpE) 4th Year

Secondary

: San Francisco West Central Elem. School San Francisco Agusan del Sur SY 2004-05

Elementary

: Agusan Sur National High School San Francisco Agusan del Sur SY 2000-01

E

C

U

R

R

I

C

U

L

U

M

V

I

T

A

ALVIN REY BOYLES ALEMANIA Age Address Contact Number Citizenship Religious Aff. Birth Date Birth Place Father Mother

: : : : : : : : :

19 Km. 2 Baan Highway, Butuan City Filipino Roman Catholic December 29, 1988 Baan Highway, Butuan City Sofronio Morales Alemania Ma. Felema Luison Boyles

EDUCATION College Degree

: Saint Joseph Institute of Technology Butuan City : BS in Electronics Engineering (BSECE) 4th Year

Secondary

: Agusan National High School Butuan City SY 2004-05

Elementary

: Riverside Central Elementary School Baan, Butuan City SY 2000-01

E

VII. Bibliography

•

www.keil.com/dd/dcs/datashts/nuvoton/w783057c.pdf

•

www.kitsrus.com/pdf/k148t4.pdf

•

www.cannonsports.com/Images_Internet/Internet_pdfs/TIMER S_VOL22_LOW.pdf

•

www.hobbyprojects.com/c/counters_and_timer_circuits.html

•

www.educypedia.be/electronics./circuitsbysubject.htm

•

www.electronickits.com/kit/comple/timers/canuk247.htm

•

www.circuit-innovations.co.uk/timer.html

Saint Joseph Institute of Technology Butuan City

DOCUMENTATION OF DIGITAL COUNTDOWN TIMER PROJECT IN ECE 9 Submitted to: ENGR. CATHERINE M. VERALLO Instructor

Submitted by: LEPORNIO, JERRY J. TABUNGAO, JOE RANDY B. DELGADO, KEITH MARVIN A. GENZON, VICTOR L. CABALLES, CYRUS Y. ALEMANIA, ALVIN REY B.

OCTOBER 2008