PURPOSE: To enable to control the period of after-glow. by stopping current supply to glow plugs in response to a frequency component of the pulsation voltage developed at an unrectified terminal or neutral point terminal of a three-phase AC generator for driving an engine.
CONSTITUTION: Before starting an engine, only a switch S1 is closed for heating glow plugs 4aW4d repidly by the voltage of a bettery 6. After starting of the engine, on the other hand, the switch S1 is opened for producing after-glow. In this state, the AC voltage developed at an unrectified terminal A of an alternator 3 by a comparator 21 is formed into a pulse train having a fixed width by a monostable multivibrator 22 and then into a voltage proportional to the engine speed by integrating the pulse train by a low-pass filter consisting of R1 and C1. By judging the voltage proportional to the engine speed at a comparator 23, a transistor TR1 is switched from ON to OFF. That is, in idling operation of the engine, a low voltage is produced and the output of the comparator 23 becomes high and energizes the transistor TR1, so that the contact of a relay 5 is closed and the voltage at the unrectified terminal A is applied. On the other hand, when the engine operation is shifted from the idling operation to other mode, after-glow of the glow plugs is stopped by opening the contact of the relay 5.
| JPS62170772 | STARTING AIDS |
KUWAKADO SATOSHI
HASHIKAWA ATSUSHI
KATOU KAZUKI
KUMOI TOMIO
NIPPON DENSO CO