| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric power steering device capable of promoting realization of smaller size and assurance of reliability.SOLUTION: On an electrification path from a power source (DC power source B) to a motor drive part 13, a power supply relay 17 for electrical conduction/shielding of the electrification path is provided. The power supply relay 17 is arranged in back to back arrangement in which two MOSFETs 17a, 17b are connected in series, to allow shielding of currents in both directions. A thermistor T1 is arranged near the MOSFET17b, for detecting temperature t1 near the MOSFET17b. Then, when the temperature t1 is equal to a preset reference temperature ta or higher, it is determined that heating abnormality is occurring at the MOSFET17b. |
