| 摘要 |
PURPOSE:To increase the calorific value of heater so as to shorten the waiting time which is required to heat up intake air for stating an engine, by providing a preheat circuit, which short-circuits a part of a resistor for an electric heater provided in an intake passage, for allowing a power source to be connected so as to permit great current to be applied when preheating is required. CONSTITUTION:In starting an engine, if a key switch 1 is turned on a preheat contact 12, a resistor R2 of an electric heater 2 for heating intake air is energized by a battery B through a preheat circuit L1, and a timer 32 is simultaneously started allowing a lamp 33 to be turned on. A relatively great current is applied to the resistor R2 for heating up intake air quickly. As the output of the timer 32 is turned over allowing the lamp 33 to be turned off after a set period of time (approximate 15 seconds) of the timer 32 has elapsed, the key switch 1 is switched over to a start contact (14) side by a driver who identifies that the lamp 33 goes off. This causes a starter motor M to be actuated allowing a series circuit of resistors R1 and R2 to be energized through a starter circuit L2 so as to keep heating continuously. |
