The circuit diagram of acousto-optic electronic switch consists of AC switch, electronic switch, shaping circuit, detector and sound amplification circuit. Acousto-optic dual-control contactless switch. At night, when the light is dim, you can turn on the light automatically by voice and go out automatically after 40 seconds. When there is enough light during the day, you can't turn on the light no matter how the sound interferes. It is especially suitable for automatic control of lighting in residential buildings, office buildings, corridors, warehouses, basements, toilets and other public places. It is an automatic control switch integrating sound, light and timing, which is energy-saving and convenient.

The working principle is shown in the figure, which is the principle block diagram of acousto-optic timing switch. It consists of piezoelectric ceramic buzzer, sound amplification, detection, shaping, lighting control, electronic switch, timing circuit and AC switch. The working principle is shown in the figure. Ceramic piezoelectric buzzer B converts sound into DC control voltage. During the day, after receiving light, the resistance of photodiode vD6 becomes smaller, and the potential of pin 13 of integrated circuit A is clamped to the ground potential of pin 7, so pin 5 is at a low potential, and C4 has no charge. ⑧ The foot is at a low potential, the thyristor vs is turned off, and the light bulb is not lit. When Vs is turned off, the DC voltage is reduced by R 1 and then added to the upper ends of the filter capacitor c2 and the Zener diode vD5 to fully charge c2. When pin 14 and pin 7 of A are charged, the DC voltage is 4v. VD5 is a zener diode, and the regulated voltage is about 4v to ensure that the voltage across c 2 does not exceed 5v. When vD6 is not illuminated in the dark, the resistance of vD6 increases, and the potential at the 13 pin will rise to the on voltage. The electronic switch inside A is activated by voice control, and the charge stored in c2 is transferred to c4 through pin ⑤, and then the potential of pin ⑤ rises, and C4 sends the d C voltage to pin l0 through K6 for amplification. Through the output pin 8, it gives a positive bias voltage to the vS control terminal through the current-limiting resistor R2, and VS is turned on and the light bulb is lit. It emits light for about 40S, and the potential of 8 pins is low after discharge, and there is no trigger voltage at VS, and R is in reverse bias state. Then v3 turns off the power and lights. The light-emitting time of the bulb is determined by the parameters of [time constants R6 and C4]. R 1 and R2 have the functions of reducing voltage and starting impulse current to vs, respectively, protecting the bulb and prolonging its life. C 1 is an anti-interference capacitor, which is used to eliminate the light bulb jitter.