incandescent light life extension switch circuit

Published:2011/9/12 22:02:00 Author:John | Keyword: incandescent light, extension switch | From:SeekIC

Incandescent light’s filament is with large thermal resistance and very small cold resistance. So at the moment of opening light, the impact current flowing through the filament is very large. It can be very easy to make the filament burn within damages. Life extension’s switch can be a good solution to this problem, just as shown in the figure.It can effectively extend lamp’s life greatly. When switch S is connected, the voltage across the capacitor can not change suddenly and the voltage across C is zero. The thyristor VT deadlines without triggering voltage. At this moment, the current flowing through the bulb E is the half-wave current rectified by VD2. The light bulb is pre-heated with darkness and the inrush current is very small.



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