| 摘要 |
PURPOSE:To constitute an electric timer circuit which is suitable to a ventilation fan in a flush toilet, kitchen, or the like by feeding a current to a load at the same time when a switch is ON and by maintaining the feeding to the load for a while after the switch is turned OFF. CONSTITUTION:This circuit consists of the load circuit which connects fan motor M of the ventilation fan as a load to power terminals X and Y of the AC power supply via switch SW, relay RL-C which operates by normally open relay switch RL connected in parallel to switch SW, and the delay OFF control circuit which opens this relay RL-C a little bit after switch SW is turned OFF. The common connection point between contact RL-C of this control circuit and switch SW is connected to the connection point between transistor Tr2 and coil RL and also to capacitor C1 charged with a DC voltage rectified by diodes D1 and D2, and timer capacitor CT and resistance RT are both provided between capacitor C1 and normally closed contact NC of switch SW, thereby constituting the delay OFF circuit. |
