Chapter 2 Camilo

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Chapter 2 CONCEPTUAL FRAMEWORK

This chapter presents the review of related literature and studies, conceptual model and the operational definition of the terms used in the study.

Related Literature The World Book Encyclopedia (1990) pointed out that electric generator is a machine that produces electricity. Generators produce almost all of the electricity used by people. They furnish electric power that runs machine in the factories, provides lighting, and operate home appliances, generators maybe small enough to hold in one hand, the midget generators used in some scientific instruments provides a dial, or a generator maybe bigger than a house. It can supply electric power for as many as one million homes. Harkavy (1994) pointed out that electric circuit is path followed by an electric current. It consists of three basic parts. An energy source (e.g., battery or generator) that converts non- electrical energy into electrical energy, an output device (e.g., motor or lamp) that uses electrical energy to do work, and a connection (e.g., wire or cable) that allows electric currents to flow between the source and output device. Circuits can be switch on and off. An open circuit has

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gaps, preventing the current from completing its path, while a close circuit has no gap. Electronics Enthusiasts (1995) Aircon Energy Saver describes how important energy saving and power control. By means of power consumption there are several things that are saved to energy and safe to use. It also describes the protection against under voltage and over voltage. Electronics Enthusiasts (1997) Selecting a Linear Voltage Regulator describes the types of linear regulator, its characteristics and is intended for specific application. Selecting the best type for circuits require trade-offs in performances, availability and cost. www.rise.org.nu/info/Applic/array (2007) describes that inverters are necessary if main voltage appliances are to be used. In assessing the cost of the total system, it maybe more economical to purchase an inverter and mass produced consumer appliances than to use low voltage DC appliances which can be more expensive than normal appliances. www.unlimited-power.co.uk/DC_to_AC_Inverters (2002) stated that there are typical applications for inverters include: micro wave ovens, television, video recorders, computers, power tools and monitoring/ communication equipment. It also includes two main types of inverters, Modified Sine Wave and True sine Wave.

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www.uoguelph.ca/~antoon/circ/555dcacinverter.html (2001) shows a schematic diagram of DC to AC inverter that produces an AC output using 555 timers that is configured as a low frequency oscillator, tunable range of 50 to 60 Hertz.

Related Studies Alcasid’s (2003) study entitled “Energy Saver: A technical Feasibility Study”, sought to design, construct, test and try-out and revise energy saver which was constructed using locally available materials. The researchers concluded that it is capable of reducing power consumption of electric motor-driven equipments and it can also be used as power-on delay and low voltage protector for compressor type appliances. It was found out that its mechanism is so simple that electronics hobbyist and individuals interested in saving electricity can construct a similar one with the guidance of an electronic expert. Evangelista’s (1994) in his seminar paper entitled “Regulated Power Supply Trainer: A technical Feasibility Study”, sought to design, Construct, test and try-out and revise a regulated power supply trainer using locally available materials. The finding of the study is that it is feasible to design not only a power supply trainer but also other kinds of trainer that can be helpful in teaching Electronics Technology.

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Prathab’s (1993) in Implementation of SMPS (Switch Mode Power Supply) stated that DC/AC inverters (50 Hz) are used in many cases as back up supplies. In most cases DC supply is a 12 DC volts battery. And for stepping up the inverted voltage 12/ 230 transformer is used which is very bulky since operating frequency is very low (50 Hz). There are small portable inverters that have been manufactured using other methods to step up 12 DCV to higher level. There are many different techniques. One method is to use dc/dc boost converter in first stage voltage to 230 AC. Reña’s (2003) study entitled “Basic Electronics Experimental Board: A Technical Feasibility Study, sought to design, construct, test and try-out and revise Basic Electronics Experimental Board which was constructed using locally available materials. It was found out that it was much cheaper than its commercial counterpart. The researchers concluded that the device can be utilized by shop instructors and administration to provide more meaningful learning on the concept and principle of electronics technology. Zuron’s (1999) study on the Advantages of the Sine Wave Voltages that it is has soft temporal rise of voltage and the absence of harmonic oscillations, which cause unwanted counter forces on engines, interferences on radio equipment and surge currents on condensers. On the other hand, square wave voltages can be generated very simply by switches, e.g. electronic valves like MOSFET transistor.

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Conceptual Model Conceptual model that guided the study is shown in Figure 1.

INPUT

THROUGHPUT

OUTPUT A

1. Ideas theories from related studies and literatures.

1. Design

2. Supplies and materials.

2. Constructing (Prototype)

3. Tools and equipments.

3. Testing

COMPLETED

4. Revising

AND READY TO USE MULTIPOWERED

4. Labor

WORKING

5. Cost.

TABLE

Figure 1 Conceptual Model of the Study

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Definition of Terms The key terms and the operational definitions are: AC. Also known as alternating current, an electric current that reverses at regularly recurring intervals the frequency being determined by the frequency of the alternator supplying the current and the successive half waves were being. Battery. Two or more cells electrically connected for producing energy. Circuit. This refers to the source followed by an electric current passing from its source through a succession of conductors and back again to the starting point.. Converter. A device used to convert energy to another energy Current. Responsible to the opposition of resistance. DC. Also known as direct current, an electric current flowing in one direction and substantially constant in value. Dual-powered. Composed of two power source the AC and DC. Inverter. A machine, device or system that changes direct current to alternating current by mechanical or electronic means. Power. The capacity to do work, any supply having voltage and current that can run up a system or device. Power Supply. A device for converting available electric service energy into direct current energy at a voltage suitable for electronic components. .

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Supply. To make additions to by way of supplement, to provide satisfaction or compensation for make good by providing a substitute. Variable Regulated Power Supply. A power supply that vary its voltage either lower or higher amount. Voltage. Also known as the EMF (electromotive force) that drives up current to a certain conductor. Watt. Unit of power consumption, amount or capacity of electricity used..