| 摘要 |
PURPOSE:To miniaturize an apparatus and reduce the cost, by switching voltage doubler rectification and direct rectification each other according to AC power source voltage by means of a circuit having a solid state photo-relay or the equivalent function. CONSTITUTION:When electric current is made to flow between terminals 1, 2 of a solid state photo-relay SSR, then a diode LED is made luminous and is communicated with a photo-triac PT to be communicated between terminals 3, 4. When the voltage of AC power source is 220V, the voltage applied to the Zener diode ZD2 is higher than the Zener voltage and DC voltage E is generated at a point P2. And by the voltage E, a transistor (Tr)Q1 is put in a conductive state with saturation voltage between a collector and an emitter for the TrQ1. Accordingly, a TrQ2 is put in a non-conductive state, and current does not flow between the terminals 1, 2 of the solid state photo-relay SSR but the TrQ2 is put in a non-conductive state between the terminals 3, 4, and the DC output voltage can be kept almost constant. |
