| 摘要 |
PURPOSE:To eliminate another power source by connecting a light emitting diode connected in anti-parallel with a photocoupler in series with the primary coil of a step-down transformer and applying a power source voltage thereto. CONSTITUTION:An operating circuit is insulated from a power source 13 only by a step-down transformer 1, the brightnesses of light emitting diodes 7, 7' are varied by the variation in the primary current of the transformer 1, the internal resistances of phototransistors 9, 9' and the oscillating number of a blocking oscillator having a capacitor 12 and a trigger element 14 are varied by the illumination to control the phase of a triac 16, thereby controlling the phase of the power of a load 15. In this circuit, the diodes 7, 7' connected in anti-parallel with the photocouplers 6, 6' are connected in series with the primary coil of the transformer 1 to be applied with the power source voltage, and since the blocking oscillator utilizes the power source voltage, another power source is not necessary. |
