Patent · US Expired

Power supply with two output voltages

US4835668A · kind A · utility

9Cited by
5References
10Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 29, 1988
Grant dateMay 30, 1989
Priority date
Expiry dateFeb 29, 2008

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S323/902
  • WIPO fieldAudio-visual technology
  • WIPO sectorElectrical engineering

Abstract

A power supply circuit for generating two direct voltages. A preload, having a tap for deriving the second voltage, is arranged between the lead conveying the first voltage and a reference potential. To prevent mutual influences between the two voltages, the preload is in the form of a series arrangement of at least one resistor and a plurality of reverse-biassed semiconductor diodes, an abrupt change of the differential resistance occurring above a given value of the current through these diodes. A controllable semiconductor element for controlling the second voltage is incorporated between the tap and the lead conveying the second voltage. The first voltage may be an E.H.T. for a final anode of a picture display tube, the second voltage is then a focussing voltage for a focussing electrode of this tube.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.