| 摘要 |
PURPOSE:To permit to effect effective conduction by a method wherein the conduction is interrupted when the operating condition of a diesel engine has become high speed during conducting an after glow while high voltage is impressed when temperature decrease is large upon reopening the conduction. CONSTITUTION:When vehicle speed exceeds a predetermined value, or 10km/h for example, after starting the engine, the output 18a of a vehicle speed detecting circuit 18 becomes H, the output of an after glow timer circuit 12 is forced to change to H under continuing the operation thereof, a driver circuit 15 puts a transistor 16 OFF and the conduction for the glow plug 7 is interrupted. When the vehicle speed is reduced to a speed lower than a predetermined value or 5km/h, for example, before the time-up of a timer, a sub relay 3 is put ON, the output 9c of a temperature detecting circuit 9 becomes L, the output 10a of the driver circuit 10 becomes also L, the transistor 11 is conducted to put a relay 5 ON and the voltage of a battery 1 is impressed on the glow plug 7 without passing through a dropping resistor 4 in case the temperature of the glow plug is lower than the lower limit returning temperature of the temperature detecting circuit 9. Thereafter, the conduction is effected through the resistor 4 when the temperature of the glow plug is returned to the predetermined temperature. |
