AUXILIARY STARTER FOR PREHEATER IN DIESEL ENGINE

摘要

PURPOSE:To improve the durability of control accuracy in comparison with a contact type device by employing a transistor for a switching means as a glow plug temperature control. CONSTITUTION:When a key switch 1 is turned on, a voltage fed from a battery 2 and unified by a Zenor diode ZD is applied on an operation amplifier OP 1, 2 which constitute a part of a control circuit. In this instance, if the glow plugs G1- G4 are at a low temperature, the output voltage of a thermocouple 3 which is a glow plug temperature detecting means is low, making the output voltage of the operation amplifier OP1 at low level and the output voltage of the operation amplifier OP2 which works as a comparator at high level. As a result of this, a transistor TR5 is turned on, turning on transistors TR1 to TR4 to actuate the glow plugs G1-G4. After that, if the output voltage from the operation amplifier OP2 becomes low level due to a temperature rise of the glow plugs G1-G4, all of the transistors TR5 and TR1-TR4 are turned off to stop the power supply to the glow plugs G1-G4.