| 摘要 |
PURPOSE:To remove a current limiting resistance by rendering the ON state characteristic of a triac photocoupler to be high impedance, thereby reducing a pulse surge current. CONSTITUTION:When an input signal switch 2 is closed, a current is supplied from a DC power source 1 to a light emitting diode 12a of a triac photocoupler 12, the diode 12 emits a light, a triac unit 12b optically coupled with the diode is turned ON, a gate current limited by the internal impendance is applied to a main triac 7, and the triac 7 is thus turned ON. A current from an AC power source 5 is supplied to a load 6, and the ON voltage of the triac 12b is high. Accordingly, the triac 12b is immediately turned ON by the ON of the triac 7. Thus, a pulse surge current is reduced to remove the current limiting resistance. |
