| 摘要 |
PROBLEM TO BE SOLVED: To provide an electric apparatus that suspends a power circuit 10 before a smoothing capacitor 15 opens its pressure valve or is destroyed.SOLUTION: The electric apparatus includes a fuse 12 interposed in series on an AC line L1, a startup resistor 18 connecting a DC line L3 to the gate of an FET 17, and a Zener diode 30 having a cathode connected to the DC line L3 and an anode connected to a self-excitation oscillation control circuit 19. When the Zener diode 30 yields, the self-excitation oscillation control circuit 19 stops on-off control over the FET 17 to keep it on. A short-circuit breakdown occurs between the gate and source or between the drain and the source of the FET 17. The short-circuit breakdown causes excess current in the power circuit 10 to fuse the fuse 12. |
