| 摘要 |
PURPOSE:To prevent unnecessary electric conduction in the preheat controller of an engine through glow plugs, by starting the electric conduction at detection of operational preparation for the engine and ceasing the electric conduction for the engine still in a stop state when a prescribed current value is obtained. CONSTITUTION:A key is turned, and a detector circuit 17 outputs H by low engine temperature or a comparator circuit 8 outputs H by low temperature of glow plugs 1 themselves, if an engine is in a stop state, a transistor 27 and relay 26 are turned on to close a self holding switch 21, and the contact of a main relay 3 is closed becuase of H output of the comparator circuit 8, then the glow plugs 1 rapidly increase temperature even if an engine key switch 20 is not closed. If the glow plug reaches prescribed temperature, the output of the comparator circuit 8 becomes L, and the transistor 27 is turned off to open the self holding switch 21. Though the glow plug is cooled, power is not fed to the comparator circuit 8 and its peripheral circuits when the engine is not intended to start, then the main relay 3 and subrelay 4 are not operated. |
