| 摘要 |
PURPOSE:To stably control temperature of a glow plug without causing the necessity for using a current limiting resistor, by intermittently conducting an electric current in the captioned device used for a Diesel engine or the like and rapidly controlling preheat before a start of the engine. CONSTITUTION:If a key switch 2 is closed by the driver, a timer circuit 17 generates an output only for a time t1 and an input to a setting terminal corresponding to glow plug temperature about 900 deg.C by resistors 141, 142 in a comparator circuit 14 to close a relay 8. After an electric current is started to flow, if plug temperature reaches about 900 deg.C, an output of the circuit 14 is inverted to open the relay 8 not flow a current in a glow plug. A timer circuit 15 is triggered, and a pulse of level L is output for a certain time and input to the circuit 17. In consequence, after a fixed time (tOFF) from relay opening, a relay circuit is closed. And then if the plug temperature again reaches about 900 deg.C, output of the circuit is inverted to open the relay circuit. In this way, a glow plug can stably control temperature. |
