EP 0173155 B1 19920205 - POWER SUPPLY FOR THE LIGHT SOURCES OF FREQUENCY-MODULATED OPTICAL DETECTORS
Title (en)
POWER SUPPLY FOR THE LIGHT SOURCES OF FREQUENCY-MODULATED OPTICAL DETECTORS
Publication
Application
Priority
DE 3431996 A 19840831
Abstract (en)
[origin: US4707838A] A current supply is disclosed for frequency-proportional optical sensors, preferably fiber-optical sensors, having a constant amplitude modulated over time. The delay time of the modulation is kept constant as well in the current supply in order to increase the accuracy of measurement. A variable resistor that is connected in series with the LED or the semiconductor laser is used for this purpose. This resistor may for example be a photoresistor illuminated by a light source and the resistance value of this resistor is varied by an open-loop or closed-loop control circuit. The variable resistor may also be a resistor that is heated by its own current.
IPC 1-7
IPC 8 full level
G05F 1/63 (2006.01); H05B 44/00 (2022.01)
CPC (source: EP US)
G05F 1/63 (2013.01 - EP US); H05B 45/30 (2020.01 - EP US)
Designated contracting state (EPC)
DE FR GB IT SE
DOCDB simple family (publication)
EP 0173155 A2 19860305; EP 0173155 A3 19880107; EP 0173155 B1 19920205; DE 3431996 A1 19860313; DE 3585347 D1 19920319; US 4707838 A 19871117
DOCDB simple family (application)
EP 85110083 A 19850812; DE 3431996 A 19840831; DE 3585347 T 19850812; US 83624286 A 19860305