| 摘要 |
PROBLEM TO BE SOLVED: To prevent breakage of a switching element which is materialized in an FET or the like, by monitoring the voltage applied to an inductive load, thereby appropriately detecting overcurrent. SOLUTION: The output signal from a comparator 22 is inverted to low level, when the monitored voltage falls under the reference voltage, and an AND circuit 21 cuts the PWM signal from a PWM output circuit 12, and compulsively turns off an FET 16. But, since a current begins to flow gradually to a linear solenoid L, after the FET 16 is turned on, a period when the monitored voltage is lower the reference voltage exists even at normal times. Accordingly, this device is arranged, so that the switch can be switched to the side a by changeover switch 23, until a specified time passes after the FET 16 is turned on, and this validates the PWM signal, regardless of the output signal of the comparator 22, and inhibits the compulsive turning off of the FET 16. |
