Incandescent lamp life extension electronic controller (1)

The working process of the circuit is: when the switch S is turned on
, since the voltage across the capacitor cannot change suddenly, the voltage across the capacitor C
is zero, and the thyristor is cut off without triggering voltage
. At this time, the current flowing through the bulb H is
the half-wave current rectified by the diode VD2. The bulb preheats and emits dim light, and the inrush
current is very small. If the capacitor C is charged by VDI and Rl,
after a delay of about 0.6s, when the voltage across C rises and reaches
the turn-on level of the thyristor vs, vs is turned on, and the bulb H is lit normally. Since
there is a 0.6s buffer delay time between the cold state and normal lighting of the bulb , the service life of the bulb is extended.