Timing dimming lighting power saving circuit

The timer lighting power-saving circuit is a power-saving device that integrates lighting timing adjustment and dimming control lighting functions. It can be installed in
public corridors, family courtyards, bathrooms, etc. for lighting purposes. For the timing function only, it can be used for
timing of household appliances such as electric blankets and electric fans . Installed in the bedroom, its low-light lighting function will also make the room's tone and atmosphere unique, and it can also achieve obvious energy-saving
effects.
    (1) Circuit principle The circuit principle diagram is shown in Figure 16-33. The power supply is 220V from the mains, transformed by transformer T and
rectified by the rectifier bridge (VD1~VD4), filtered by capacitor c], stabilized by W7805, and turned into direct current, which supplies power to the (NE555) integrated circuit. The delay circuit in the circuit is composed of integrated circuit
IC555, capacitors C4, c5 and button SB. Turn on the power switch S and press the button SB. IC 55 is set, the output pin ③ is at high level, the bidirectional thyristor VTH is triggered to conduct, and the light bulb EL lights up. When SB is released, the power supply charges C4 through RP1. When the charge is higher than the 2/3 Vm threshold level, IC555 resets, and the output of pin ⑧ is low, causing the bulb EL to extinguish. The low-light lighting LED remains in working condition after switching on S. Adjust RP2 (470n) for dimming control.