| 摘要 |
PURPOSE:To reduce a power loss and to provide the capability of recovering in case of a failure in commutation by constituting a charging circuit for a commutating capacitor by using a transistor (TR), a diode applied with a reverse bias, and a resistor supplied with a base current. CONSTITUTION:When a pulse is applied from a trigger circuit 7 to the gate of a main thyristor 3, a base current flows through the loop of a DC power source 1, a resistor 12, the base and emitter of an npn TR11, a commutating capacitor 4, a main thyristor 3, and the DC power source 1, and the commutating capacitor 4 is charged through a resistor 13 and the TR11. When a pulse signal from a trigger circuit 8 is applied to the gate of an auxiliary thyristor 6, the charge of the commutating capacitor 4 is discharged through the loop of the commutating capacitor 4, a diode 10, the auxiliary thyristor 6, the main thyristor 3, and the commutating capacitor 4, and the main thyristor 3 turns off. Then, the commutating capacitor 4 is charged with the opposite polarity. |
