this led bar graph contains only three LED s and each LED show the low, mid range and high frequencies according to the audio played, this bargraph can be used in audio amplifiers, the circuit is for a 40w amplifier,  connect the circuit in parallel to the speakers and no external power supply is needed........
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Step 2: Circuit diagram

Picture of circuit diagram
make the circuit according to the circuit diagram
usbg3rd2 years ago
what is the working principle of the circuit? correct me if i m wrong.
when high frequency comes then the capacitor gets short (theoretically) then all LED's should glow simultaneously. and in case of low frequency no led should glow

also what is the voltage rating of the capacitors?
sooraj619 (author)  usbg3rd2 years ago
since the values of the capacitors are different all leds will not glow simultaneously

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