| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an abnormality detection device that is for use in a low side drive or high side drive electromagnetic device drive device and is suited to detect a layer short circuit of an output terminal which causes an unnecessary operation of an electromagnetic device in a non-driving period of the electromagnetic device.SOLUTION: In a drive device 1 for a solenoid valve 2, a side of a coil 3 of the solenoid valve 2 opposite to a battery voltage VB is connected to an output terminal 5, and when a conduction switch 7 is turned on, the output terminal 5 is brought to a ground potential VG to cause a current flow through the coil 3. In the device 1, a resistor 21 and a plurality of diodes 23 generate a voltage lower than the battery voltage VB by a constant voltage Vcn as a threshold voltage Vthr. While keeping the conduction switch 7 off, a microcomputer 9 determines that there is an abnormality occurring if a comparator 31 determines that a voltage Vout of the output voltage 5 is lower than the threshold voltage Vthr.</p> |
