| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a switch diagnosis device which allows for fault diagnosis of a switch while connecting a power supply and a load, even if the voltage on the load side is unlikely to change in response to on/off of the switch connecting the power supply and the load, and to provide a switching circuit for use in the switch diagnosis device, and a switch diagnosis method.SOLUTION: A first rectifier element D1 for preventing a current, flowing from a load 5 side of a first switch 10 to the first switch 10 is connected in series with the load 5 side, a second switch 20 is connected in parallel with these series circuits, while furthermore a first resistor R1 is connected between the connection point of the first switch 10 and the first rectifier element D1, and the ground potential. At first, the second switch 20 is turned on, and then the first switch 10 is turned off/on. A voltage generated in the first resistor R1 by a current from a battery 3 side is detected, respectively, when the first switch 10 is turned off/on, and a determination is made whether the first switch 10 is turned off/on, on the basis of the voltage thus detected.</p> |
