Television apparatus power supply
US4866525A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 1, 1988 |
| Grant date | Sep 12, 1989 |
| Priority date | — |
| Expiry date | Nov 1, 2008 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N3/185
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
An SCR switch of a switch mode power supply is coupled between an unregulated supply voltage and a filter capacitor. A regulator oscillator generates trigger pulses for controlling a switching operation of the SCR switch of the power supply to produce an output supply voltage that energizes a deflection circuit. The regulator oscillator produces trigger pulses that are applied to the SCR switch during both power-up and power-off operation. A resistor coupled between the unregulated supply voltage and the filter capacitor maintains the filter capacitor charged during power-off operation to prevent the trigger pulses from causing the latching operation in the SCR switch throughout the power-off operation. In this way, an audible parasitic vibration sound is not being generated by the power supply during the power-off operation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.