Adjustable frequency drive
US4508976A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1983 |
| Grant date | Apr 2, 1985 |
| Priority date | — |
| Expiry date | Jan 14, 2003 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH03K17/0826
- WIPO fieldBasic communication processes
- WIPO sectorElectrical engineering
Abstract
A circuit for driving a power transistor that forms a part of an inverter circuit used in motor control in which the circuit is switched at high voltages. The motor drive circuit isolates and amplifies a control signal so as to operate the power switching transistors. The base drive circuit employs two characteristics of power transistors to derive maximum protection and maximum performance simultaneously. This control is accomplished by sensing both the collector-to-emitter voltage of the power transistor as well as the base-to-emitter voltage thereof. In an alternate embodiment described herein, a feedback circuit is also provided sensitive to collector-to-emitter voltage for shortening the try-time associated with the power transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.