Television receiver high voltage generator protection circuit
US4343028A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 21, 1981 |
| Grant date | Aug 3, 1982 |
| Priority date | — |
| Expiry date | Jan 21, 2001 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/20
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A high voltage generator of a television display is responsive to an alternating voltage, such as a retrace pulse voltage, for developing an ultor voltage at an ultor terminal. A protection circuit for the high voltage generator includes a comparator that develops a television display disabling signal when activated. A circuit that develops a sense voltage representative of the ultor voltage is coupled to an input terminal of the comparator so as to develop the disabling signal when the ultor voltage exceeds a predetermined level. To provide an overload disabling capability, an ultor beam current sensing circuit is coupled to the input terminal of an operational amplifier. The output terminal of the amplifier is coupled to a bias voltage source and to an input terminal of the comparator. When the ultor beam current exceeds a predetermined level indicative of high voltage generator overload operation, the operational amplifier applies the bias voltage to the comparator input to energize the comparator into developing the disabling signal. The magnitude of the bias voltage is such as to activate the comparator in substantial independence of the value of the ultor voltage sense voltag…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.