IC555 based Multicolor LED Lamp Circuit Diagram

Magic lamp produces different coloured lights with basic colour LED's , thus producing a fascinating effect. This multicolor led lamp circuit is based on two ICs namely NE555 which works as clock generator in astable mode and CD4017 which is a decade counter.

NE555 astable generates a clock for the circuit, which provides an oscillating wave to the output pin 3 of IC1. You can vary the speed of oscillation with the help of VR1. The frequency of oscillation of 555 timer can be calculated by:

f=1.44/(R1+2*(VR1)*C1). Continue reading to find out how circuit is made and how it works.

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Fig. 1: Prototype Of Multicolor led Lamp Circuit On Breadboard

f=1.44/(R1+2*(VR1)*C1)

Now this wave is supplied to CD4017 decade counter pin 14 which provides a clock for its working. Here after receiving the clock input CD4017 starts its counter from zero and it advances by one each time pin 14 goes high. When it reaches the ninth count, counter goes back to zero and the counter starts again. As the count progresses, respective pin goes high to provide the output. For instance in the circuit diagram shown, first is pin 3 which represents zero(Q0) meaning it will provide you the output first. The second is pin 2- it represents one(Q1), Similarly pin four represent two(Q2) and so on. CD4017 will count up to nine then it will reset again but in our circuit we are using it to count up to six.

In this circuit we are using seven output pin and two input pins. The output are from pin 1 to 5, pin 7 and 10. Input pin are clock (pin14)and reset (pin15). We have connected the pin 6 to reset pin because we want after sixth count it will start counting again. Colour control of the circuit is based on simple switching logic using twelve 1N4148 diodes.

When power supply is given to the circuit, NE555 oscillator provides a clock pulse to pin 14 of IC2 which in turn starts the counter and different colour outputs are generated. You can also change the colour sequence by interchanging the output connection of decade counter.

For mixing the light from the LED you can use some translucent material so that you can properly distinguish the colour. For this you can use piece of Wax or you can use Alum (Potassium Aluminum Sulfate). Before placing translucent material described above, cover the LED’s properly.