| 摘要 |
PURPOSE:To prevent SCR from malfunctioning by providing a zero-cross solid state relay circuit with a resistance connected between a light oscillating element and SCR and a Zener diode connected between the cathode of SCR and the emitter of the oscillating circuit. CONSTITUTION:Between the anode and gate of SCR5 constituting a zero-cross solid state relay, light oscillating element 6 irradiated with light from light emitting element 8 is provided, Zener diode 7 is connected between the gate of element 6 and the cathode of SCR5, and the parallel circuit of resistance 10 and capacitor 11 is further connected between the gate of SCR5 and its cathode. A relay circuit of this constitution is provided with resistance 12 connected between the gate of SCR5 and element 6 and Zener diode 13 connected between the emitter of element 6 and the cathode of SCR5. Then, diode 13 prevents element 6 in an OFF state from operating due to momentary potential variation such as a noise, etc., thereby preventing SCR5 from malfunctioning. |
