| 摘要 |
PURPOSE:To protect a glow plug of a diesel engine and contrive to enhance the restartability of the engine by feeding a charged voltage of a capacitor into a comparator through a diode. CONSTITUTION:In a controlling circuit 9 for rapid preheating, a diode 24 is connected between a connecting point for a resistor 20 and a capacitor 10 and an input terminal at one side of an operational amplifier 23. When a key switch 1 is turned OFF, the charge accumulated in the capacitor 10 is discharged through the resistor 20, a normally closed contact 7b of a relay 7 and a parallel circuit consisting of a coil 6a of a relay 6 and a preheating indication lamp 22, and the terminal voltage of the capacitor 10 falls in conformity with the temperature fall characteristic of the glow plug 19, so that the terminal voltage always conforms to the temperature of the plug 19. When the key switch 1 is turned ON for restarting, the rapid preheating time is controlled according to the temperature of the glow plug 19. |
