公开(公告)号：US5028825A

公开(公告)日：1991-07-02

申请号：US423090

申请日：1989-10-18

申请人： Christopher A. Smith ,  George K. Woodworth

发明人： Christopher A. Smith ,  George K. Woodworth

IPC分类号： H02M1/08 ,  H03K17/79 ,  H03K17/795

CPC分类号： H03K17/79 ,  H03K17/7955 ,  Y10T307/773

摘要： The improved gate drive circuit provides a continuous gate current whenever there is sufficient anode-to-cathode voltage difference across the SCR. This approach described herein eliminates the need to monitor and reapply SCR gate current after each commutation due to load current distortions. Previous SCR gate driver designs used a pulse train of gate currents to provide a means of keeping the SCRs turned on. The pulsed gate control approach has gaps in the SCR's operation and requires significant circuitry that dissipates much more drive energy. Energy for this improved driver circuit is derived from the SCR anode-to-cathode voltage differential. This eliminates the need for individual power supplies to provide isolated gate signals for each SCR. This self-powering feature reduces the intricacy of controlling multiple SCRs in multi-phase or unreferenced power systems. Flexibility provided by this method allows high power SCRs to be directly interfaced to a digital processor-type controller.