ENGINEERING PHYSICS

SECOND YEAR ( 2012 )

PRACTICAL TRAINING ( ELECTRONIC PROJECT )

Members of group CHEW WEI YI 117033

LOKE JIA CHERNG

Project LED Switch Circuit

Lecturer Mr. Wong Chow Jeng

INTRODUCTION

Solar Energy has long been the Holy Grail of the Non-Conventional energy sources.

Many stupendous efforts have been exerted in an attempt to harness this free & simple form

of energy for common man .This energy can be used as an alternative for electrical energy.

The basic and major obstacle has been the huge infrastructure cost required initially.

Efforts are being made for many years to reduce the huge initial cost, although the

initial cost reduction seems to be a big challenge .However the benefits offered by its usage

are so alluring that we can ,with no harm, neglect the disadvantage. We have designed and

conceptualized our project model taking into consideration the lighting loads of the big

educational institutes, which seems to be quite higher.

Solar energy driven equipment are being less efficient, use of solar energy for

conventional lighting scheme is hardly of any use. So to find an alternative to the

conventional lighting scheme we thought of replacing it by LED lighting scheme. Thus we

hope this will be a small but important step in helping increase the use of non-conventional

energy worldwide &also to protect the environment, reduce the load on conventionally

generated electricity grid among many other envisioned advantages.

For our project, we have to build a circuit that contain IC 555 and more than 20

LEDs. Our group member have decided to make LED Chaser Cicuit. In this circuit, we have

used two Ics which is 555 and NE555 to drive the LEDs. The LEDs lights one by one for a

period of 1 second and the cycle repeats giving the running light appearance. This LED

Chaser is used in christmas tree.

1.0 LED Chaser Circuit

This is the circuit of a simple LED chaser. Resistors R1, VR1 and capacitor C1 act as

the timing components and the output pulses are available from the output pin 3 of IC1.

These pulses are given to the input pin 14 of the Johnson decade counter IC CD4017. Out

of the 10 outputs of IC2, eight outputs are used to drive the LEDs. The ninth output pin 9

is connected to the reset pin 15 to stop the counting. So that the cycle repeats. With the

value of C1, each LED remains on for 1second. When one LED turns off, the second on

turns on. This cycle repeats giving the running light appearance. Resistor R3 keeps the

input pin 14 of IC2 low after each pulse. VR1 adjusts the speed of LED chasing.

1.1 CIRCUIT IN MULTISM

1.2 COMPONENT AND FUNCTIONS

NO. COMPONENT FUNCTIONS

1. Light-Emitting Diode ( LED ) LED is a light emitting semiconductor diode

that emits light. LEDs are most often used in

the form of an indicator light in electronic

devices, traffic signal lights, musical

instruments and dashboards in cars and in

houses etc. The nature of the light emitted can

be visible, infrared or ultraviolet.

2. Resistor The resistor is the most common electronic

component and is used to limit and/or control

the voltage and current in an electronic

circuit. Electrical resistance describes how an

electrical conductor (a wire) opposes the flow

of an electrical current (flow of electrons). To

overcome this opposition a voltage (energy

source) must dropped (used) across the

conductor (wire). Resistance can be described

by ohms law.

3. IC IC is used in a variety of timer.

4. Capacitor Basically, a capacitor stores input energy for

later release. Some common uses of

capacitors are to accumulate a small power

input for release at one time (camera flash

units) and also can be used as temporary

battery.

5. Variable Resistor Providing a continuous selection of resistance

values.

6. Battery Batteries store energy being produced by a

given generating source, and when this source

is unavailable this energy can be be used by

the load. The inclusion of storage in any

energy generating system will increase the

availability of the energy.

7. Rheostat The variable resistor is connected in series

with a load, and two of its three terminals are

used -one of the fixed terminal and the slider

terminal.

1.3 APPLICATION

Figure 1 Christmas Tree

1.4 COST ESTIMATION

No. Items Quantity Amount ( RM )

1. Vero Board 1 6.00

2. LED ( Green and Yellow ) 24 4.80

3. Battery 1 5.20

4. Resistor 3 0.15

5. Capacitor 2 0.40

6. Variable Resistor 1 1.70

7. Wire 2 meter 1.00

8. IC 555 1 0.90

9. IC 4017 1 1.30

10. Battery holder ( 9 volt ) 1 0.20

TOTAL 21.65

1.5 RESULTS

Firstly, there are some flaws happened where our LEDs suddenly did not functioning on the PCB Board. After doing some changes, finally its functioning successfully. This means our project on LED Chaser is success. We can submit this project on due date.

1.6 REFERENCES

http://electroschematics.com/6170/led-chaser/ http://electroschematics.com/6217/led-scanner/