Patent · US Expired

Power supply for outdoor lighting systems using high frequency

US4906901A · kind A · utility

16Cited by
4References
27Claims
0Family size

Assignee

Inventor

Key dates

Filing dateAug 29, 1988
Grant dateMar 6, 1990
Priority date
Expiry dateAug 29, 2008

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02B20/00
  • WIPO fieldElectrical machinery, apparatus, energy
  • WIPO sectorElectrical engineering

Abstract

A power supply for outdoor lighting systems accepts ordinary household alternating current of 120 volts at 60 hertz. The power supply uses a digital switching means to convert this current into a lower voltage at a higher frequency. Typically, these values are 28 volts at 20 kHz. This high frequency signal is then supplied to the lights through a transformer. The use of a higher voltage than that normally used for such systems improves the operating efficiency of the lighting system and allows lights to be placed at a greater distance from the power supply. The higher frequency signal reduces the bulk and cost of the transformer. The voltage and current supplied to the lights can be altered by changing the frequency of the signal entering the transformer. A feedback circuit monitors the signal supplied to the lights and automatically varies the frequency so as to keep the voltage and current within predetermined operating limits.

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