| 摘要 |
PURPOSE:To achieve glow plug control having simple circuitry and never consuming power uselessly by conducting power to the glow plug with correspondence to target temperature region variable with engine temperature. CONSTITUTION:A glow plug 19 is controlled of power conduction through a computor 10 prior or post of starting because of excessive heat. When conducting power temperature of plug influenced by excessive heat of plug 19 and receiving heat from engine is measured and compared with preset target level then opening/closing of first switch 23 and second switch 24 is controlled by current regulating circuit 21 to bring the temperature of plug 19 within target region. The target temperature region is variable in accordance to the engine temperature. Here the potential of battery 20 and the potential at the joint of detecting resistor 22 and plug 19 are converted into digital values and the glow plug temperature is calculated by control program on the basis of said values. Conequently power can be saved while the circuitry can be simplified because differential amplifier circuit is not employed. |
