| 摘要 |
PURPOSE:To make an abormality display continuously by making a lighting display even after automatic resetting by a display circuit corresponding to an automatic reset type abnormality detection switch. CONSTITUTION:A fan forced oil heater is provided with an automatic reset type shockproof switch S1 and a manual reset type overheat preventive temperature switch S2 as safety devices. When this temperature switch S2 operates to a side NO, both relays RLA and RLB are turned off and released from in a self-holding state to cut off power supply to a control part L for fuel, and a contact b1 is placed at a side NC to turn on a pilot lamp LED2. Further, when the shockproof switch S1 operates to a side NO, a relay RLB is short-circuited to turn off and the contact b1 is switched to the side NC. Then, the relay RLA is turned off to cut off power supply to the control part L. Further, the pilot lamp LED1 is turned on, but even this switch S1 is reset automatically, the LED1 is still on since the contact b1 is on the side NC. This resetting is performed with a push-button switch PB2. |
