| 摘要 |
A switching circuit protector switches a semiconductor device (11) provided in a switching circuit connecting a power supply (VB) to a load (RL), from a PWM drive state to a DC drive state when an estimated temperature of a cable of the switching circuit estimated by a temperature estimator (22) exceeds a threshold temperature (Tth), in the state where the semiconductor device (11) is controlled to operate in the PWM drive state to drive the load (RL). Therefore, when an overcurrent is caused in the cable, the estimated temperature exceeds the threshold temperature (Tth) so as to break the semiconductor device (11). Accordingly, the switching circuit can surely be protected by the switching circuit protector. |
