| 摘要 |
PURPOSE:To prevent malfunction by flowing an operating current only in a short time when an actuator does not operate actually by transformer coupling, or intercepting the operating current only in a short time when the actuator does not stop actually, and testing a circuit. CONSTITUTION:The output of a logical circuit 22 is off in a normal state, so the actuator 28 is not in operation. A test circuit 31 applies an AC voltage to the 2nd winding 23-2 of a transformer 23 only in a short time shorter than the operation time of the actuator 28 to generate induced electric power at the 3rd winding 23-3, flowing a pulse current from an AC power source 30 to a triac 26a and the actuator 28. This current is detected by a current pickup 32 and a discriminating circuit 33 judges the soundness of the actuator circuit. When the output of the logical circuit 22 is on and an AC current flows through the 1st transformer winding, such a negative-phase AC current as magnetic flux by the 1st winding is canceled is flowed through the 2nd winding and AC electromotive force generated at the 3rd winding is eliminated to confirm the soundness of the circuit similarly. |
