Incandescent lamp life extension circuit 6

(6) Incandescent lamp life extension circuit No. 6
    The circuit is shown in Figure 2-34. This circuit also uses a two-level power supply mode
, with the first level being half wave and the second level being full wave. The 555 time base integrated
circuit A is used as the delay protection link. This circuit also has a function: when the grid phase voltage rises above 225V (can be
adjusted and set by the potentiometer RP), the circuit will automatically enter the protection state, reducing the light bulb to half-wave power supply ; and when the grid voltage returns
to normal , and automatically put into full pressure work.