| 摘要 |
PROBLEM TO BE SOLVED: To provide a solenoid driving circuit by which a trouble can be diagnosed with certainty from the induced electromotive force generated on a solenoid. SOLUTION: In the constitution wherein high voltage VH is given to a distribution line 7 through a high voltage switch element 8, solenoids SL1 to SL4 are overdriven by high voltage VH through the distribution switch elements 15 to 18 which are provided corresponding to the solenoids SL1 to SL4, and a retaining driving and a demagnetization driving are performed continuously, the intensity of inducted electromotive force, generated on the solenoids SL1 to SL4 when the high voltage switch element 8 is in OFF state, is detected by the distribution line 7 through the distribution switches 15 to 18, whether the above-mentioned intensity reached the prescribed value is discriminated, and this is used as a trouble diagnostic signal DG. When a demagnetization driving operation is conducted, the distribution switches 15 to 18 are turned off, and the voltage on the solenoid is prevented from creeping on to the distribution line 7. |
