Sound sensor light

Circuit description: This circuit is mainly composed of audio amplifier circuit and bistable trigger circuit. Q1 and Q2 form a secondary audio amplifier circuit. The audio signal received by the MIC is coupled to the base of Q1 through C1. After amplification, it is directly fed from the collector to the base of Q2. A negative square wave is obtained at the collector of Q2. to trigger the bistable circuit. R1 and C1 limit the frequency response of the circuit to about 3kHz, which is the high sensitivity range. When the power is turned on, the state of the bistable circuit is that Q4 is cut off, Q3 is saturated, and LED1 does not light up. When the MIC receives the control signal, it outputs a negative square wave after two levels of amplification. After differential processing, the negative spike pulse is added to the base of Q3 through D1, causing the circuit to quickly flip and the LED to light up. When the MIC receives the control signal again, the circuit flips again and the LED goes out. If the LED light circuit is connected to other circuits, voice control of other circuits can also be achieved through J2. Working voltage: DC3V-5V