| 摘要 |
PURPOSE:To provide a solar sign using a relatively small solar cell area by turning on a light-emitting load by the supply to a load circuit of AC power which is pinned and latched at a secondary zero-cross point determined by a circuit constant. CONSTITUTION:A thyristor of a photothyristor coupler PSC 1 is ignited in response to a positive signal pulse f3 from a transmitter 1, and a potential difference produced between both ends of a resistance R12 is applied to the gate of a main switch S+, and a main current is passed toward a ground terminal from a power terminal +E through a load circuit 8. In this case, the phase of a microcurrent flowing through an auxiliary path coincides with the phase of the main current. Therefore, when the phase of the main current is opposed to a primary zero-cross phase, the thyristor of the coupler PSC1 is turned off, the potential of the resistance 12, i.e., the gate potential of a FET is eliminated, and the switch S+ becomes nonconducting; the reverse component of the main component is fed back and recovered. When a negative signal pulse f4 arrives, a minus auxiliary path and an inverter perform similar action. |
