| 摘要 |
PURPOSE:To reduce the current duty of an element to be protected and the loss of the circuit by transferring the storage energy of a condenser through a circuit of the condenser, a reactor and an auxiliary switching element to a reactor and discharging the energy. CONSTITUTION:A condenser 2 is connected in parallel with a switching element 1 to be protected through the first discharge preventing diode 3, and a series circuit of the primary coil of a reactor 107 having a secondary coil and an auxiliary switching element 8 having self-arc-extinguishing function is connected in parallel with the condenser 2. The taps c at both ends of the secondary coil of the reactor 10 are connected to a load side terminal of a power source 5 and the tap (a) is connected to the positive electrode side terminal of the power source 6 through the second diode 9, and a rectifying circuit in which a rectifying diode 11 and a condenser 12 for another power source are connected in series is connected in parallel between the intermediate tap (b) and the tap (c). In this manner, the current duty of the switching element to be protected and the loss of the circuit can be reduced. |
