| 摘要 |
PURPOSE:To enable sure ON, OFF control with a simple circuit constitution, by controlling the bidirectional thyristor switches of a plurality with a sole drive circuit having PNP and NPN transistors of multi-collectors. CONSTITUTION:When the bidirectional thyristor switches 19 and 20 consisting of four-terminal PNP thyristors in anti-parallel connection are controlled with a sole drive circuit 29 at the same time, the collectors of PNP transistor Tr30 and NPN Tr31 in the drive circuit 29 have respectively each two collectors 32, 33 and 34, 35, and they are connected respectively to the gate corresponding to the two bidirectional switches 19 and 20. When the switch 16 of the circuit 29 is closed, normal direction bias is given to Tr30, 31, current flows to each two collectors of each Tr, to simultaneously control the bidirectional switches 19 and 20. |
