Automatic street light control circuit

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Automatic street light control circuit [Copy link]

Automatic street light control circuit

This device can automatically turn on the street lights at dusk and automatically turn off the street lights at dawn, achieving automatic control of street lights on/off. The circuit is shown in the figure below.
Circuit features: Delay is used at the critical point of street lights turning on at night and turning off during the day. In this circuit, the city power is transformed by transformer B, rectified by QL, and stabilized by three-terminal 7812 (this can ensure the accuracy of the controller). It is supplied to the control circuit after filtering by C2. During the day, the internal resistance of the SR photoresistor is very small under light, BGI is saturated and turned on, BG2 is turned off, BG3 is turned on, BG4 is turned off, and the street lights are not lit; at dusk, the internal resistance of the SR photoresistor becomes larger, causing BGI to turn off, BG2 to turn on, BG3 to turn off, BG4 to turn on, J1 to pull in, DB to light up, thereby achieving automatic control of street lights. The debugging of this device is relatively simple. Adjusting W1 can make the street lights turn on and off under appropriate light, and adjusting W2 controls the charging and discharging delay of the electrolytic capacitor C3, thereby avoiding the influence of thunderstorms on the controller. If the load power is large, you can connect an intermediate relay at DB to drive the AC contactor. Jl relay uses JZC-23FDCl2V, intermediate relay uses JTX type AC220V, if there is no photoresistor, phototransistor 3DU can be used instead, other components have no special requirements.
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