| 摘要 |
PURPOSE:To prevent the damage of an element by holding a gate signal by a detection signal as it is when two GTOs are simultaneously conducted as a series unit, and applying an extinguishing signal to the GTO of the remaining series unit. CONSTITUTION:A plurality of circuits provided with a series unit of two GTO2 through a fuse 4 are connected to a DC power source 1, and the output is supplied to a power system 8. A DC shortcircuit detector 5 for detecting the simultaneous conduction is provided by the fact that the both applied voltages become near zero on the basis of the voltage between the anode and the cathode of the GTOs, the signal is inputted to a gate control circuit 6, thereby holding the gate signal of the series units which are simultaneously conducted as it is, the fuse 2 is molten, and an extinguishing signal is generated to the remaining series unit. Accordingly, the damage of the GTOs which are simultaneously conducted can be prevented, thereby preventing the influence to the other series unit. |
