Using NE555 to make an incandescent lamp life extension controller

In the figure, S is the power switch of the incandescent lamp, and kl is the normally closed contact of the relay K. When you need to turn on the light, close the switch S. The 220V
alternating current is stepped down by the capacitor Cl to limit current, VD2 ~ VD5 bridge rectifier and VD6 stabilized voltage output to provide 12V DC voltage for the time base
circuit NE555 . Since the voltage at both ends of the capacitor C3 cannot change suddenly, the trigger end of the time base circuit, namely pin 2, is low level, the time
base circuit is set, and the output end pin 3 outputs a high level, and the relay K is powered on, and its normally closed contact kl tripped, at this time, the
AC current is limited by the diode VDI half-wave rectifier and the resistor Rl to supply power to the incandescent lamp H to reduce the inrush current. Then capacitor
C3 is charged through RP, and the potential continues to rise. When it reaches y3 VDD (that is, about 8v), the time base circuit is reset. When pin 3 outputs
low level, relay K is released when it loses power, its normally closed contact kl is reset and closed, VD1 and Rl are short-circuited, and the bulb starts to be
powered normally. At this time, the charge stored in C3 is discharged through VD7 and R2. You can prepare for the delay when turning on the lights next time.
    Adjusting the potentiometer RP can change the delay time of the circuit, and the delay time can be estimated by the formula kl.l RPx C3.