Timing socket principle circuit diagram

As shown in the figure is the timing control circuit, and CZ is a power socket controlled by timing .

The mains power is stepped down through the transformer, bridge rectified, and filtered to obtain 12V voltage for circuit operation. 555 is connected to form a single stable circuit, 3DJ6F is connected to form a constant current source to charge the timing capacitor C, and the 555 output is connected to the relay J1 line package to achieve switching control. To start, press the switch AN to start the timing, so 555 outputs high level and the timing starts. If K is at the "1" position at this time, J1 is in the timed release state, and K is at the "2" position, which is the timed suction state. After the timing starts, 3DJ6F charges C with a constant current until the voltage on C rises to 8V and the timing ends. C is discharged through the 7th pin of the 555, and the 555 output becomes low level to cause J2 to change state. The CZ socket can be controlled by scheduled power on (K connected to "2") or scheduled power outage (K connected to "1").

W is a timing adjustment potentiometer with an adjustable range of about 150 minutes. W can use an exponential (Z-type) potentiometer, making short timing easy to achieve. The relay can be used in the JQX-4F-DC12 type, with a coil DC resistance of 450 ohms, a DC working voltage of 12V, a pull-in voltage of less than 9V, a pull-in current of about 25mA, and a contact capacity of AC 220V/3A. The power transformer can be a small transformer for signal lights with 220V/10V specifications.

W can be calibrated with a standard clock and time scaled to facilitate presetting the timing time.