Power supply protection circuit
US4916366A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 21, 1988 |
| Grant date | Apr 10, 1990 |
| Priority date | — |
| Expiry date | Nov 21, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/20
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A horizontal deflection circuit includes a flyback transformer. A secondary winding of the flyback transformer is coupled in series with a diode switch to produce a trace rectified supply voltage that energizes a vertical deflection amplifier. The diode switch also provides switching operation in an East-West diode modulator. During, for example, service mode operation, when the vertical raster is collapsed, the trace current in the secondary winding is substantially reduced. The reduced trace current is sensed for producing a control signal that causes the peak current supplied by the diode switch to the diode modulator to be smaller than the trace current in the secondary winding. This ensures that the diode switch remains conductive throughout horizontal trace, thereby, preventing an undesirable increase in the supply voltage from occuring.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.