Global Patent Index - EP 1050197 A1

EP 1050197 A1 20001108 - ELECTRONIC BALLAST HAVING AN OSCILLATOR SHUTDOWN CIRCUIT FOR FLUORESCENT TUBES OR LAMPS

Title (en)

ELECTRONIC BALLAST HAVING AN OSCILLATOR SHUTDOWN CIRCUIT FOR FLUORESCENT TUBES OR LAMPS

Title (de)

ELEKTRISCHES VORSCHALTGERÄT FÜR ENTLADUNGSLAMPEN MIT ABSCHALTVORRICHTUNG

Title (fr)

BALLAST ELECTRONIQUE MUNI D'UN CIRCUIT D'ARRET DE L'OSCILLATEUR POUR TUBES OU LAMPES FLUORESCENTS

Publication

EP 1050197 A1 20001108 (EN)

Application

EP 97951039 A 19971230

Priority

CA 9700995 W 19971230

Abstract (en)

[origin: WO9935892A1] An electronic ballast having particular application for driving small diameter fluorescent tubes or lamps (such as the T2, T4 and T5 sizes). The electronic ballast has a shutdown circuit (D13 and TR3) by which to remove power to an oscillator (TR1 and TR2) when the tube or lamp (26 and 28) is close to the end of its useful life or when an abnormal condition occurs such that a rise in operating voltage is detected. The shutdown circuit (D13 and TR3) detects the rise in the operating voltage of the tube or lamp (26 and 28) and energizes a relay (40) through the conduction path of a photoresponsive transistor (TR) that is rendered conducting by a light emitting diode (48). The relay (40) directs power away from the oscillator (TR1 and TR2) and towards the control electrode of the photoresponsive transistor (TR) to hold said transistor on and thereby disable the ballast.

IPC 1-7

H05B 41/29

IPC 8 full level

H05B 41/298 (2006.01)

CPC (source: EP)

H05B 41/2985 (2013.01)

Citation (search report)

See references of WO 9935892A1

Designated contracting state (EPC)

AT BE CH DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE

DOCDB simple family (publication)

WO 9935892 A1 19990715; AU 5473598 A 19990726; EP 1050197 A1 20001108

DOCDB simple family (application)

CA 9700995 W 19971230; AU 5473598 A 19971230; EP 97951039 A 19971230