Music Operating Dancing LEDs light

In this project, we are going to build an amazing circuit named Music Operating Dancing LEDs. You have seen the DJ lights or Disco Lights, that Turn ON and OFF with music. These lights run according to the length and volume of music, basically, these are build to sense high-intensity sound like Bass sound. So these lights follow the high pitch beats in music like drum beat sound and Turn ON and OFF according to music change. You can increase and decrease the sensitivity of this circuit.


First of all, you should build Dancing LEDs, which just follow a set pattern and can only control the speed. Then next level Music Operated Dancing LEDs, that LEDs will flash according to music, just like DJ Lights or disco light. The Musical LEDs circuit is based on NPN transistor BC547. This circuit is very simple and easy to make, it can be built just with a few basic components.

Circuit Diagram

Components Required

  • Condenser Mic    1
  • NPN Transistor BC547 5
  • Resistances – 10k (2), 1k (4), 1M (1)
  • Ceramic Capacitor 100nF (1)
  • LEDs (4)
  • 9v Battery (1)
  • Breadboard and connecting wires

Working Explanation of Music Operating Dancing LEDs

Condenser mic picks up the sound signals and converts them into voltage levels in this Simple LED Music Light Circuit. These voltage signals are further fed to the R-C filter through (R2 and C1), to eliminate the noise. Further, a BC547 transistor (Q1) is used to amplify the inputted signals, from the R-C filter. Then these music signals are given to the array of four transistors(Q2, Q3, Q4, and Q5). In this circuit transistor work as an amplifier, and run four LEDs according to the sound style. This creates an interesting sequence of dancing LEDs. We can adjust the sensitivity of MIC by changing the value of R2 and C1, by using the formula for R-C filter:  F = 1/ (2πRC).

Here F is the cut-off frequency, which means only allow frequency above than F. It can be easily deduced that the more the value of RC, less the cut of frequency and higher the sensitivity of MIC. And higher the sensitivity of circuit means MIC can pick low volume-sounds, hence LEDs can glow on low also. So by adjusting its sensitivity we can make it less to reacts only on high note beats or we can also make it more sensitive to react on every little beat in the music. .We have set its sensitivity at a moderate level.

Condenser Mic should be connected properly in  circuit, according to its polarity and sensitivity. To determine the polarity of MIC you should look at mic terminals points, the terminal which has three soldering lines is a negative point.

Transistor BC547 is an NPN transistor, which is being used here as an Amplifier. NPN transistor acts as an open switch when no voltage applied on its Base (B) and it acts as a closed switch when there is some voltage at its base.

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