DEVELOPMENT OF A COIN SLOT PREPAYMENT SYSTEM FOR

HOUSEHOLD ELECTRICITY

A Technical Research

Presented to

The Faculty of Computer Engineering Department

University of Mindanao

In Partial Fulfillment

ofthe Requirement for the Degree

Bachelor of Science in Computer Engineering

Joebert S. Arquiola

Ismael M. Dampac

Dijie S. Osnan

August, 2012

APPROVAL SHEET

This technical research entitled “DEVELOPMENT OF A COIN

SLOT PREPAYMENT SYSTEM FOR HOUSEHOLD

ELECTRICITY”prepared and submitted by JoebertArquiola, Ismael

Dampac, and DijieOsnanhas been examined, accepted and is hereby

endorsed.

Engr. Rolieven P. Cañizares,MEP

Thesis Adviser

PANEL OF EXAMINERS

Approved by the committee on oral examination.

Engr. Randy T. Angelia, CpE Chairperson

Engr. Esther Consuelo Tan, MEPEngr. Lynneth C. Sorronda,PECE

Member Member

Accepted in partial fulfillment of the requirements for the Degree of

Bachelor of Science in Computer Engineering.

Engr. Charlito L. Cañesares Dean, College of Engineering

University of Mindanao

Abstract

The purpose of the study was to develop prepayment system electricity

by coin slot machine and notifies the daily usage of electricity. In addition, this

study provides paperless so the end users may pay as much as they want as

long as they have a positive balance and also this prepayment system will be

particularly implemented in a boarding house.

I. Introduction

Electricity is most needed and become more important because

everything in our world today depends on having the power to keep them

running and electricity services are essential for meeting all the basic human

needs. This study provides the customer with convenient method of paying for

the electricity, particularly for those on low incomes or who find it difficult to

pay the electric bill as a whole. The study would provide the customer

convenient method to pay their electricity bill, especially those on low incomes

or to those who find it difficult to pay the electric bill as a whole.Nowadays, a

number of apartments werestill implementing a mastered-metered form of

billing in which allocation of the payment is divided number of apartment

units. With this kind of setup, all consumers pay an exactly the same amount

regardless of the consumer’s income, capability to pay and level of

consumption, With then coin slot payment system, there will be no arrears to

collect and the tenant can control their budget for they can manage the use of

electricity according to their needs.

According to Robins (2010), more than half of all low-income families

with a mortgage have struggled to pay their electricity. Between 9 per cent and

11 per cent of households in the middle-income groups were similarly

struggling to pay their electricity bills. It was also found that low-income

households were more likely to seek help from their power supplier, as were

households with three or more occupants, since they used more electricity and

thus faced higher bills, or were renting or faced larger proportionate mortgage

repayments. The tribunal’s chief executive, Jim Cox, said it was clear low-

income households with financial commitments such as a mortgage were

finding it hard to keep up.

House Deputy Speaker Lorenzo Tañada said that the Philippines now

holds the unenviable record of having the highest cost of electricity in Asia,

beating Japan, Singapore and its more developed neighbors. In addition, at

P8.14 per kilowatt-hour, the price of electricity in the country is now the

highest in Asia that is why millions of Filipinos have been suffering from

spiralling costs of electricity and 14 million Filipino families have no

electricity in their homes (Diaz, 2011).

According to Davao Light and Power Company (2011), the new

distribution rates were being approved by the Energy Regulatory Commission

and covering the period July 1, 2011 to June 30, 2012. For residential

customers the average increase is P0.1942 per kWhr. The impact to a

residential customer whose monthly usage is 175 kWhr is an increase in its

total distribution charges of P33.99/month. Including the effect of VAT and

franchise tax, the increase will be P0.2192 per kWhr or P38.37/month.

The proponents proposed to provide a convenient method of paying

electricity bill with budgeted amount of money. By the coin slot machine, the

tenant will not be more attentive in collecting monthly bills.

II. Objectives of the Study

This research study aimed to design and develop a coin slot prepayment

system for household electricity.

Specifically, the study was addressed:

1. To perform a function test

2. To present the cost of developing the system

III. Significance of the Study

Paying electricity bills every month can produce a problem especially to

those who have low income. In addition, some other community especially in

the squatters’ areas, most of the people who rented and lived there were just

using neighbourhoods’ mainline because they cannot afford to have their own

mainline. The development of a coin slot prepayment system for household

electricity was intended only to those who cannot afford the monthly electricity

bills as well as to those who used electricity when they need.

IV. Target Beneficiaries / Clients

This study benefited mostly the following:

End User.The output of this study helped them to avail electricity with

respect to their needs.

Tenant. The coin slot prepayment system in household electricity could

collect anytime the owner wants.

V. Review of Related Literature

This section presents different studies related to this applied research.

Circuit Breaker

Circuit breakers are a vital part of home safety. A basic understanding of

how a circuit breaker works will help you troubleshoot any electric problems

and help you determine when it’s time to call an expert (Pickett, 2012).

According to Harris (2011), the circuit breaker is an absolutely essential

device in the modern world, and one of the most important safety mechanisms

in your home. Whenever electrical wiring in a building has too much current

flowing through it, these simple machines cut the power until somebody can fix

the problem. Without circuit breaker (or alternative, fuses), household

electricity would be impractical because of the potential for fires and this

would be result from simple wiring problems and equipment failures.

Electricity

Electricity is a general term encompassing a variety of phenomena

resulting from the presence and flow of electric charge. These include many

easily recognizable phenomena, such as lightning, static electricity, and the

flow of electrical current in an electrical wire. In addition, electricity

compasses less familiar concepts such as the electromagnetic field and

electromagnetic induction (Bird, 2007).

Henderson (2012) said that a commercial power company charges

households for the energy supplied on a monthly basis. The bill for the services

typically states the amount of energy consumed during the month in units

of kWhr. This unit is a power unit multiplied by a time unit is a unit of energy.

A household typically pays the bill on the basis of the number of kWhr of

electrical energy consumed during the month. Thus, the task of determining the

cost of using a specific appliance for a specified period of time is quite

straightforward. The power must first be determined and converted to kW. This

power must then be multiplied by the usage time in hours to obtain the energy

consumed in units of kWhr. Finally, this energy amount must be multiplied by

the cost of electricity on a currency/kWhr basis in order to determine the cost in

a particular currency.

Infrared Sensor Circuit

According to Infrared (IR) Sensor (2012), this circuit is one of the most

basic and popular sensor modules. In electronics, this sensor is analogous to

human’s visionary senses which can be used to detect an obstacle which is one

of its common applications. In robotics, a group of such modules are used so

that a robot can follow a line pattern.

IR sensor circuitis a circuit that includes use of electronic devices that

emit or receive through the detection of radiation to experience some aspects of

the environment. Infrared (IR) sensor device normally used to detect the

temperature or the heat of an object and also the movement. When the sensor is

only intended to measure the level of infrared radiation only, not the other way,

then it is usually called a Passive Infrared (PIR) sensor.

Basically, that every object has or emits some form of thermal radiation.

Radiation is invisible to our eyes, but usually this is in the infrared spectrum.

For this reason,IR sensor circuitis required, which can receive and interpret

radiation can be detected in the spectrum (The Basic of IR Sensor Circuit,

2012).

Peripheral Interface Controller

According to Vysakh (2011), Peripheral Interface Controllers (PIC) is

one of the advanced microcontrollers developed by microchip technologies.

These microcontrollers are widely used in modern electronics applications. A

PIC controller integrates all type of advanced interfacing ports and memory

modules. These controllers are more advanced than normal microcontroller like

INTEL 8051. The first PIC chip was announced in 1975 (PIC1650). As like

normal microcontroller, the PIC chip also combines a microprocessor unit

called CPU and is integrated with various types of memory modules (RAM,

ROM, EEPROM, etc.), I/O ports, timers/counters, communication ports, etc.

PIC is the IC which was developed to control peripherals devices,

alleviating the load from the main CPU. Compared to a human being, the brain

is the main CPU and the PIC is equivalent to the nervous system (What is

PIC?, 2012).

Prepaid System

According to Burns (2010), consumers of electricity these days now

have the option on having their electricity put on prepaid or post-paid plans.

Prepaid plan on electricity is where consumers deposit first or pay in advance

to be able to use electricity while post-paid plan is when a consumer pays for

his or her electricity after using it. For them to use more electricity they can just

simply load their accounts again and by loading their accounts regularly, they

also eliminate the possibility of being disconnected from the electric company.

An electric meter that has the capability to load the purchased energy, to

display real time information on how the load is being consumed, and to give a

warning that the load is close to zero providing positive buffer before

electricity is automatically disconnected. All prepaid meters should have an

average accuracy of as close as possible to the condition of zero error before

they are placed in service. Also, an electric service using a prepaid metering

system designed to allow a residential customer to purchase credit and then use

electricity until such time as the credit is exhausted (Republic Act No. 9136,

2008).

Relay

A relay is a switch that is electrically controlled. A device can enable

large signal from a smaller signal, it is like passing signals between two or

more different electronic circuit. This device is incorporated with a

electromagnet and 3 small metals. One of the small metals is movable and

normally pulled by a spring to connect on one of the 2 other metals. If the

electromagnet is saturated with a signal current the magnet will now pull the

moving metal and overpowering the spring, wherein the movable metal will

change it contact to the other metal from its normal contact state (Daintith,

2004).

Wattmeter

The wattmeter is an instrument for measuring the electric power (or the

supply rate of electrical energy) in watts of any given circuit. The instrument

which measures electrical energy in watt hours (electricity meter or energy

analyzer) is essentially a wattmeter which accumulates or averages readings;

many such instruments measure and can display many parameters and can be

used where a wattmeter is needed: volts, ampere, apparent instantaneous

power, actual power, power factor, energy in kWh over a period of time, and a

cost of electricity were being consumed (Chisholm, 1991).

Watt meters are often designed around dynamometer meter movements,

which employs both voltage and current coils move a needle. In general

construction, the instrument resembles a Siemens electrodynamometer

(Wattmeter design, 2009).

VI. Scope and Delimitations

This study focused in the way of paying electricity bills through coin

slot machine. In this system, the proponents used peripheral interface controller

as a brain system, wattmeter for reading the electricity and circuit breaker for a

connection between the device and electricity provider. The installation of

device is in the mainline together with the connection of each room, a coin slot

machineand LCD.

The testing of the device will be done using three rooms only. Also, a

drop of coins per transaction is limited to 12 drops. The value of one kilowatt-

hour in standard counting of wattmeter is more or less 600 revolutions of its

disc and the price of one kilowatt-hour is based from the Davao Light

company. However, the proponents lessen the 600 revolutions into 10

revolutions equal to 1 kilowatt-hourfor demonstration purposes only. Below 1

kilowatt-hour, the system will automatically disconnect the corresponding

room.

VII. Methods

Presented in this section are the process, diagrams, sketch, and the

overall design of the device.

The block diagram describes the whole process of the device. As you

turn on the device the PIC will perform the program. It will be the one to

control the circuit that will automatically connect or disconnect the main lines

connection to every room. The menu for the rooms, balance of wattage, and the

dropped coins will be displayed in the LCD as also being controlled by the

PIC. The sensors that are attach to every room electric meter will be the one

who will count the number of revolutions and send it automatically in the main

PIC and will communicate to the other PIC so that the system will know when

to cut the connection.

Figure 1. Block Diagram of the System

VIII. Findings of the Study

In this section presents the results of the study

Item Description Qty. Unit Unit Price Amount

2n222 30 Pieces P4.50 P135

2X16 LCD 1 Piece P350 P350

3mm Transparent Acrylic 1 Foot P180 P180

4 Gang 2-Pin Connector 1 Piece P78 P78

4MHz Crystal Oscillator 4 Pieces P40 P160

Angled Aluminum 12 Feet P230 P230

Bolt & Screw 30 Pieces P1 P30

Bosny Spray Paint 1 Piece P75 P75

Boysen Flat Wall Paint White 1 Piece P175 P175

Boysen Quick Dry Paint Black 1 Piece P90 P90

KEY

BUTTON

SENSOR

[ROOM1]

SENSOR

[ROOM1]

SENSOR

[ROOM1]

PIC16F877A

PIC16F84A

LCD

RELAY

[ROOM1]

PIC16F84A RELAY

[ROOM2]

PIC16F84A RELAY

[ROOM3]

Output Process Input

Breaker 20 Ampere 1 Piece P270 P270

Bulb 3 Pieces P30 P90

Buttons 5 Pieces P15 P75

Capacitor 100uf 10 Pieces P2 P20

Capacitor 22pf 10 Pieces P1 P10

X. References

Bird, J. (2007).Electrical and electronic principles and technology (3rd

ed.),

Newnes, ISBN0-978-8556-6

Burns, G. (2010). Prepaid and postpaid system for electricity. Retrieved

on June 7, 2012, from http://ezinearticles.com/?Prepaid-and-Postpaid-

System-for-Electricity&id=5396087

Chisholm, H. (1911). In Encyclopedia Britannica (vol. 29, pp. 202).

Huntingdon: Cambridge University Press.

Daintith, J. (2004). A dictionary of computing. Retrieved on December

17, 2011, from http://www.encyclopedia.com/doc/1O11-relay.html

Davao light implements new distribution rates. (2011). Retrieved on January

15, 2012, from

http://www.davaolight.com/index.php?option=com_content&view=article&

catid=76%3Ajuly11&id=1085%3Adavao-light-implements-new-

distribution-rates&Itemid=116

Diaz, J. (2011). Phl power cost now highest in asia. Retrieved on January 14,

2012, from

http://www.philstar.com/Article.aspx?publicationSubCategoryId=66&article

Id=710471

Harris, T. (2011).How circuit breakers work.Retrieved on January 15, 2012,

fromhttp://electronics.howstuffworks.com/circuit-breaker.htm

Henderson, T. (2012).Electricity: Electric Circuits. Retrieved on May 27,

2012, from http://www.physicsclassroom.com/calcpad/circuits

Infrared (ir) sensor. (2012). Retrieved on May 28, 2012, from

http://www.engineersgarage.com/electronic-circuit/infrared-ir-sensor

Pickett, M. (2012).Understanding circuit breakers. Retrieved on January 15,

2012, from http://www.servicemagic.com/article.show.Understanding-

Circuit-Breakeers.14264.html

Republic Act No. 9136. (2008). Rules for prepaid retail electric service using a

prepaid metering system. Retrieved on June 1, 2012, from

http://www.erc.gov.ph/pdf/Draft%20Revised%20Rules%20for%20prepaid

%20service%2011.11.08.pdf

Robins, B. (2010). Low-income families, especially home buyers, struggle to

pay power bills. Retrieved on January 14, 2012, from

http://www.smh.com.au/lifestyle/life/lowincome-families-especially-home

buyers-struggle-to-pay-power-bills-20101216-18zqr.html

The basic of ir sensor circuit. (2012). Retrieved on May 28, 2012, from

http://www.hqew.net/circuit-diagram/IR-Sensor-Circuit_5884.html

Vysakh.(2011). Peripheral interface controller (pic). Retrieved on May 27,

2012, from http://www.circuitstoday.com/peripheral-interface-controller-pic

Wattmeter design. (2011). Retrieved on December 19, 2011, from

http://www.allaboutcircuits.com/vol_1/chpt_8/11.html

What is pic? (2012). Retrieved on January 14, 2012, from

http://piclist.com/images/www/hobby_elec/e_pic1.html