Simple speaker protection circuit, The active speaker protection circuit is working based on 3 transistors. It’s the best amplifier protection circuit at a cheap rate. You can get the components in any cheap electronic shops.
Circuit Diagram
Why a speaker protection needs for an amplifier
The normal audio signal is a very small voltage. So we need the amplifier to high power signals so we are using the normal amplifier or PA amplifier. When the power amplifier working the output signal in the sinewave form. When the signal gets distortion happens the signal will transform to a square waveform. It will block the movement of the voice coil and further burn the voice coil. So to prevent the distortion or Entrance of DC current.
Working of circuit
The audio signals entering through the 10k resistor. The audio to be rectified by the diodes. Then the voltage reaches the base of the c945 transistor. If any DC voltage detected in Audio output the transistor gets on. Then the relay turned on and cut the connection between the speaker and the amplifier.
What are the diodes values?
4007