| 摘要 |
PROBLEM TO BE SOLVED: To judge layer short and current leakage which are not complete disconnection and short, as imperfect current application, when imperfect current application of a current applying means or a load is judged. SOLUTION: A first and a second reference MOSFET's QB, QB' are connected in parallel with a power MOSFET QA interposing in a power supplying line from a battery 1 to a running sensor S. Two reference resistors Rr1, Rr2 whose resistance values are so adjusted that a current of the maximum value and a current of the minimum value of an ordinary current in the sensor S flow are connected in series with the first and the second reference MOSFET's QB and QB', respectively. A voltage between the drain and the source of the power MOSFET QA which corresponds to a current actually flowing in the sensor S is compared with the voltages between the drains and the sources of the first and the second reference MOSFET's QB, QB' which voltages correspond to currents equivalent to the maximum value and the minimum value of the ordinary current of the sensor S which flow in the reference resistors Rr1 and Rr2. Based on the compared result, generation of short circuit and disconnection is judged.
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