This music dancing LEDs circuit is using ten LEDs, which will blink one after one on sound or music. The circuit is using two ICs and can be divided into two parts. The first part is a sound detector or sensor circuit that is built around a CA3140 IC. It is an operational amplifier IC and used in this circuit in
comparator mode. The sensitivity of the sound detector part can be adjusted with the 10K variable resistor. The second part is built with a 4017 decade counter IC. At the output of that IC there are 10 LEDs, which will blink one by one or in sequence on music, or any sound.
Working of the circuit
The electret microphone receives the sound signals and converts them in to electrical signals. These electrical signals are amplified by the CA3140 IC and available at its output pin6 and goes to the clock input pin14 of the CD4017 IC that will activate each LED one by one or in sequence on each signal received. The circuit can be operated from 6 to 12 volt DC.