Power supply fault protection circuit
US4907116A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 9, 1988 |
| Grant date | Mar 6, 1990 |
| Priority date | — |
| Expiry date | Jun 9, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH02H7/1213
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
A MOSFET power switching transistor in a DC-to-DC converter of a television apparatus has a drain electrode that is coupled via a primary winding of a chopper transformer to an input supply voltage. A first signal at a given frequency causes, during normal operation, alternate conduction and nonconduction in the transistor. A second signal is generated that is proportional to the voltage developed across the internal "on" resistance of the transistor when the transistor is conductive. The second signal is clamped when the MOSFET transistor is nonconductive. The second signal is coupled via a current sensing arrangement to the transistor gate. The second signal prevents the transistor from further conducting when the amplitude of the second signal exceeds a predetermined value that corresponds with a predetermined limiting threshold level of current in the transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.