The LASCR output coupler for figure 1(c) can be used in applications where a low-level input voltage is required to latch a high voltage relay for activating some kind of electro-mechanical device. When LED is forward-biased, the light produced by it is transferred to the phototransistor when is turned ON thereby producing current through the external load.įigure 1(b) shows a Darlington transistor coupler which is used when increased output current capability is needed beyond that provided by the phototransistor output. Such isolators allow circuits to interface with different voltage levels and grounds, etc.Īn optocoupler or optical isolator consists of a light source such as LED and a photodetector such as a phototransistor as shown in figure 1(a) and is available in a standard IC package. The usual purpose of isolation is to protect from high-voltage transient, surge voltages, and low-level electrical noise that could result in an erroneous output or damage to the device.
230000005540 biological transmission Effects 0.000 claims abstract description 30.238000005253 cladding Methods 0.000 claims abstract description 45.238000002955 isolation Methods 0.000 claims abstract description 50.230000003287 optical Effects 0.000 title claims abstract description 102.Application granted granted Critical Publication of US4946239A publication Critical patent/US4946239A/en Anticipated expiration legal-status Critical Status Expired - Fee Related legal-status Critical Current Links reassignment GEORGIA TECH RESEARCH CORPORATION, A NON-PROFIT GA CORP. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.) Filing date Publication date Application filed by Georgia Tech Research Corp filed Critical Georgia Tech Research Corp Priority to US07/249,828 priority Critical patent/US4946239A/en Assigned to GEORGIA TECH RESEARCH CORPORATION, A NON-PROFIT GA CORP. Original Assignee Georgia Tech Research Corp Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
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Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Expired - Fee Related Application number US07/249,828 Inventor Jeff P. Google Patents US4946239A - Optical power isolatorĭownload PDF Info Publication number US4946239A US4946239A US07/249,828 US24982888A US4946239A US 4946239 A US4946239 A US 4946239A US 24982888 A US24982888 A US 24982888A US 4946239 A US4946239 A US 4946239A Authority US United States Prior art keywords cladding optical isolator core tapered lens Prior art date Legal status (The legal status is an assumption and is not a legal conclusion.