| 摘要 |
PROBLEM TO BE SOLVED: To provide a solenoid drive circuit capable of properly detecting (failure detection) a short circuit in a solenoid. SOLUTION: One end 8a of a solenoid 8 is connected to a microcomputer 15 through the intermediary of a first voltage dividing circuit 21 and a first filter 22, and the other end 8b is connected to the microcomputer 15 through the intermediary of a second voltage dividing circuit 23 and a second filter 24, and one end voltage V1 and the other end voltage V2 are obtained at the ends 8a and 8b of the solenoid 8 by alignment of timing and inputted into an A/D converting circuit in such a manner where one is inputted first and then the other next. A microcomputer core unit judges whether a short circuit occurs or not, depending on the signals outputted from the A/D converting circuit. The occurrence of a short circuit can be judged by a single A/D converting circuit, so that a solenoid drive circuit can be simplified in structure. The short circuit of a solenoid is detected by the use of the one end voltage V1 and the other end voltage V2 obtained through alignment of timing, so that a short circuit can be accurately detected.
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