Patent · US Expired

Photocell controlled power supply circuit for an LED

US4330706A · kind A · utility

25Cited by
3References
1Claims
0Family size

Assignee

Inventor

Key dates

Filing dateMar 10, 1980
Grant dateMay 18, 1982
Priority date
Expiry dateMar 10, 2000

Classification

  • Technology area (CPC H)Electricity
  • CPC primaryH03F3/08
  • WIPO fieldBasic communication processes
  • WIPO sectorElectrical engineering

Abstract

A power supply for a light emitting diode (2) is governed by two photo diodes (6,7) each arranged to act upon the base of one of two transistors (3,4) in a darlington connection. One photo diode (6) is adapted to be influenced by low intensity light, whereas the other diode (7) is adapted to be influenced by light of higher intensity.

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