Light controlled night light lighting circuit

The 220V AC power is stepped down by the capacitor G, stabilized by the voltage regulator VS, rectified by the diode VD, and filtered by the capacitor G
to provide a DC operating voltage of approximately 3.3V to the IC (NE555).
    lC is connected as a light-controlled Schmitt trigger. There is no light in the room at night
, and the resistance of the photoresistor Rc is very large. When the potential of
pins ② and ⑥ of the IC is lower than Vm/3 (Vm is the 3.3V power supply
voltage), the IC is set and pin ③ outputs high level. The light-
emitting diodes LED 1 to LED 4 emit light. Since LED 1 to
LED 4 are fixed at four points of the quartz clock: 12 o'clock, 3 o'clock,
6 o'clock, and 9 o'clock respectively, they can play
a role in luminous illumination of the quartz clock. The natural light during the day or
the indoor light at night before going to bed makes the RG resistance very small, so
the potential of ② and ⑥ pins of 1C is higher than 2V∞/3, LC resets
, ③ pin is low level, LED1 ~ LED 4 are in Lights out state to save power.