Patent · US Expired

AC adaptor with power consumption reduction in unused state

US6195271A · kind A · utility

8Cited by
12References
5Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 21, 1999
Grant dateFeb 27, 2001
Priority date
Expiry dateApr 21, 2019

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY04S20/20
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

An AC adaptor that can reduce power not in use state, and a battery-operated electronic apparatus that can employ such an AC adaptor. An AC adaptor includes, (a) an input line along which an external AC voltage is input, (b) a first transformer for transforming the input AC voltage into a DC voltage at a first voltage level, (c) a switch provided on the primary side of the first transformer, (d) an output line along which a DC voltage on the secondary side of the first transformer is output externally, (e) a second transformer for transforming the input AC voltage into a DC voltage at a second voltage level that is higher than the first voltage level and for outputting the resultant DC voltage to the output line, and (f) an AC adaptor operation control circuit for comparing a voltage level across the output line with a reference voltage level, which is higher than the first voltage level and which is lower than the second voltage level, and for turning on the switch when the voltage level across the output line is lower than the reference voltage level, or for turning off the switch when the voltage level across the output line exceeds the reference voltage level. When an electroni…

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