High-voltage power supply for video display apparatus
US5982641A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Aug 7, 1998 |
| Grant date | Nov 9, 1999 |
| Priority date | — |
| Expiry date | Aug 7, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/185
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A high-voltage power supply of a video display apparatus provides an ultor voltage and a focus voltage to a cathode ray tube. A low-voltage power supply provides a variable voltage to a primary winding of a flyback transformer of the high-voltage power supply. The magnitude of the variable voltage is responsive to first and second feedback signals provided by first and second negative feedback paths. The first feedback signal is derived from the ultor voltage and is used to regulate the ultor voltage. The second feedback signal is provided by the low-voltage power supply via a path that bypasses the high-voltage power supply, and is summed with the first feedback signal to ensure that the focus voltage remains at or above a predetermined minimum voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.