Introduction - If you have any usage issues, please Google them yourself
Amplifier protection load output L, R, should all exchanges by R3, R4, C2, C3, into the earth, AC-to-ground short circuit, DC signal if all the way with DC component will be generated in the resistor-capacitor node or a positive or negative voltage, through a diode bridge, the whole into a direct current, when the voltage exceeds a diode forward voltage and Q1 conduction voltage, Q1 turns on, Q2, Q3 is turned off, the relay release play a certain channel is not normal, protection. This circuit also start delay protection: Power voltage by R2 to C4 charge voltage slowly rising voltage reaches D8, Q2, Q3 conduction voltage and relay. Load to reach-delay