Self-powered SCR gate drive circuit with optical isolation
US5028825A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 18, 1989 |
| Grant date | Jul 2, 1991 |
| Priority date | — |
| Expiry date | Oct 18, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/7955
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.