Music dancing light circuit,4500 watt using opto isolator

Imagine you have a great Hi-Fi power amplifier. But it may not be colorful for you. We recommend this, high power music dancing light circuit. You may like it. You will see the lamp flashes according to the music.

We do not dare to confirm that Is the best circuit. But at least there are interesting principles to great learning

Why we should build it?

  • Drive 3 load output depending on the sound frequency, highs, mids, and lows.
  • Control lighting with music input using Triac driver load. And, they can drive a High power up to 4500 watts load max.
  • Safety is the best important. Designers divide clearly and concisely between AC main of Load and input circuit section. So, we use an optoisolator. To protect a user from electric shock by isolate system. Music surely does not fun if electric shock you when touching the circuit.
  • Set input impedance circuit values up to 50K. So, we can use it to any sizes of audio devices. Or it will not load and make harm to your high or low watts amplifier certainly.

Main circuit ideas

Look at In Figure 1, block diagram of the Super Dancing Light.

Block Diagram of super dancing light 4500W

We enter three input signals to the filter circuit. Which each filter has featured with frequency as follows.

  • Low pass Filter (LF) will allow the frequency under 200HZ only pass through.
  • Bandpass Filter(BF) will allow the frequencies only between 200Hz to 2000HZ pass through.
  • High pass Filter(HF) will allow the frequencies only over 2000HZ up.

Look at the waveform of each sound frequency in Figure 2.

Graph Show frequencies of three Channels

And Figure2 is Graph Show frequencies of three Channels

Then, the signal from the filter circuit will flow through the Schmitt trigger circuit. It helps the light circuit flashes clearly ON and OFF. Which different from other circuits that you use to see ago.

Next, the output signal of the Schmitt triggers circuit go out to an optoisolator circuit to drive the driver circuit and output.

How this circuit works

Look at in the circuit diagram.

AC Dancing light 4500 watts using opto isolator

Here is a step-by-step process.

We enter the audio signal of the speaker into an input. VR1 is a master volume to control to enough level. Do not too high or low.

Then, the output of the master volume connects each filter via three potentiometers(VR2-VR4). Which we adjust them to control a level of signal each channel appropriately, too.

Next, see each frequency in 3 ranges:

  • Low-frequency Filter—a signal goes into R1 and C1 to transistor Q1 to pin 12 of IC1-(MN5693BN).It acts as the Schmitt trigger circuit. And the output vias the R16 to IC2-(TLQ-074) as an optoisolator.

    Next, its output drives the driver circuit-Q5(BC547) go to a TRIAC-Q8.

    Makes Lamps light up as the strength of the signal at low frequencies.

  • High pass filter—the signal comes to C3 and C4 to Q3. And the Schmitt trigger circuit pin 5 to the IC2. To drive the lamp through the Q7 TRIAC circuit, too.
  • Bandpass filter—In the same manner. The frequency range can be entered through the bandpass filter circuit. They comprise R14, C5, C2 to the base of Q2(BC557) and the Schmitt trigger circuit at pin 8. To drive the load driver Q9(BTA10-400V) as with other circuits.

Power supply circuit.

We will divide into two parts.

First—-apply power to the input control circuit like a cold circuit. Not shock us.


Another— pass power to the driver circuit Q4(BC547)-Q6(BC547) Sure it can shock us.

This causes this input control circuit isolated from the AC mains. So, It is safe for users.

How to assemble circuit

All equipment can be assembled onto the PCB, as shown in photo below.


Note: Before building should carefully study the circuit first.

All devices on assembly PCB correctly. Check the soldering tightly successfully. Then, check this PCB, that there is a short circuit or not. In particular, the point at which the AC-Line power and The control circuit may cause life-threatening.

When assembly experiment was to apply the power AC to the circuit. All bulbs lamps will be extinguished completely.

Try connecting the input signal from the amplifier speaker of any side of half time.

Be careful not Provide short circuit the input wire is determined by the output of a power amplifier may be damaged.

Try refining. potentiometer on the lamp light up by the strength of the input signal is fed into the desired range.


Although we cannot confirm this circuit work well. But I try to learn more information most to you. If you built circuit get any results to please to share we here.


I always try to make Electronics Learning Easy.

Apichet Garaipoom

I love the electronic circuits. I will collect a lot of circuit electronics to teach my son and are useful for everyone.
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