Patent · US Expired

Control circuit for LED and corresponding operating method

US6400101B1 · kind B1 · utility

176Cited by

3References

18Claims

0Family size

Assignee

Patent-Treuhand-Gesellschaft fur elektrische Gluhlampen mbH · DE

Inventors

Alois Biebl · Annweiler am Trifels, DE
Franz Schellhorn · Regensburg, DE
Guenther Hirschmann · Munich, DE

Key dates

Filing date	Feb 12, 2001
Grant date	Jun 4, 2002
Priority date	—
Expiry date	Feb 12, 2021

Classification

Technology area (CPC H)Electricity
CPC primaryH05B45/18
WIPO fieldElectrical machinery, apparatus, energy
WIPO sectorElectrical engineering

Abstract

The drive circuit is suitable for an LED array, comprising a number of clusters of LEDs, with one cluster comprising a number of LEDs which are arranged in series and are connected to a supply voltage (UBatt). A semiconductor switch (transistor T) is arranged in series between the LED and the supply voltage and allows the LED current to be supplied in a pulsed manner. A measurement resistor (Rshunt) for measuring the LED current is arranged in series between the LED and ground, with a control loop controlling the semiconductor switch such that a constant mean value of the LED current is achieved.

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