# LED Dancing light circuit with Music

This is a LED Dancing light circuit with Music. The main features are running light by changing the voice of the tiny microphone.

In the circuit, we use 4017 to drive 10 LED display. And, LM358 is preamplifier and signal converter. With a few general devices.

The goal of this circuit For enjoyment Sound experiment And the principles of basic circuits

## Operation of the circuit

Here is a simple step process of various parts.

First, apply the 9V battery to the circuit as an energy source.

Then, R1 passes some current to MIC1 (Condenser Microphone). MIC1 transforms any sound to the audio signals.

And, C1 passes only AC signal to the input. But it will block DC away.

Next, IC1/2(LM358), R2, R3, R4, R5, and C2 are the preamplifier to increase that signal to a higher level.

And, IC1/2, R6, R7, D1, and C4 are signal converter circuit. They will convert the electrical signal to the square waveform. To control the operation of pin 14 of IC2.

The IC2(4017) is popular of a decade counter circuit and can drive 10 LEDs output.

Its output pin will deliver voltage out in order sort of pin 3, 2, 4, 7, 10, 1, 5, 6, 9 and 11 in step by step.

When IC2 get a pulse input. It controls LED lights up chasing each step on the LED. It depends on the amount of an incoming square wave signal at pin 14.

The R8 limits the safety current of the LED accordingly.

You may also like these:

#### Shopping List

IC1: LM358 Low Power Dual Operational Amplifier
IC2: CD4017, Decade counter with 10 decoded outputs IC
LED1-LED10: LED as you want
MIC1: Condensor Microphone
0.25W Resistors, 5% tolerance
R1: 10K
R2, R3: 47K
R4: 1K
R5, R6, R7: 100K
R8: 820 ohms
C1, C3: 0.1uF 50V Ceramic
C2: 10uF 25V Electrolytic
C4: 0.33uF 50V Ceramic
C5: 100uF 25V Electrolytic
D1: 1N4148 Diode
B1: 9V battery Or 9V power supply circuit

Not only that. With this principle.
Christmas LED running circuit with a sound

Get Ebook: Simple Electronics Vol-03

### 5 thoughts on “LED Dancing light circuit with Music”

1. what is the function of diode connected to pin 7 of ic 2 4017