| 摘要 |
PROBLEM TO BE SOLVED: To prevent the spread of damage caused by a failure in a power supply circuit.SOLUTION: When an abnormality that drive power of a microcomputer 30 drops occurs, a potential in a base terminal of a second transistor 42 drops, the second transistor 42 is conducted, and a current flows from an emitter terminal to a collector terminal. A current is supplied to a base terminal of a first transistor 41, and the first transistor 41 is conducted. A potential in an input terminal for switching of a load-side switch 24 is dropped to a ground side, and a base terminal of a transistor 24b becomes low input. Therefore, the transistor 24b is non-conducted, a potential in a gate terminal of an FET 24a is raised to the side of a source terminal, and the FET 24a is non-conducted. Output of a rectifier circuit 16 is stopped being supplied to a load 50, and the load 50 is protected. |
