Patent · US Expired

Method and apparatus for selectively maintaining circuit power when higher voltages are present

US7671489B1 · kind B1 · utility

5Cited by
120References
12Claims
0Family size

Assignee

Inventors

Key dates

Filing dateJan 17, 2002
Grant dateMar 2, 2010
Priority date
Expiry dateMar 2, 2026

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH02J9/061
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A method and apparatus for detecting the presence of a specified voltage source and automatically switching off a second voltage source regardless of voltage source potential of the two voltage sources are disclosed. The present invention uses pinch-off of a JFET, controlled by an inverter, to control a backup power supply based on the availability of the main supply.

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