Global Patent Index - EP 0239420 A1

EP 0239420 A1 19870930 - High frequency ballast for gaseous discharge lamps.

Title (en)

High frequency ballast for gaseous discharge lamps.

Title (de)

Hochfrequenz-Vorschaltgerät für Gasentladungslampen.

Title (fr)

Ballast à haute fréquence pour tubes à décharge en atmosphère gazeuse.

Publication

EP 0239420 A1 19870930 (EN)

Application

EP 87302692 A 19870327

Priority

US 84585386 A 19860328

Abstract (en)

An electronic frequency inverter circuit receives input electrical power at a lower frequency and energizes a load circuit (35) including gaseous discharge lamps (36,37) in a range of higher frequencies. First and second semiconductors (30,31) are operated alternately by a logic circuit (40) in current mode control such that the switches operate at the higher frequency range and the frequency of current in the load circuit varies as the magnitude of said source voltage varies. The load circuit has an impedance (38) which varies with frequency such that the peak amplitude of the load current remains substantially constant despite variations in the magnitude of said source voltage to achieve a desirable crest factor for the lamp current.

IPC 1-7

H05B 41/24

IPC 8 full level

H05B 41/24 (2006.01); H05B 41/285 (2006.01)

CPC (source: EP)

H05B 41/2856 (2013.01); H05B 41/2858 (2013.01)

Citation (search report)

Designated contracting state (EPC)

AT BE CH DE FR GB IT LI LU NL SE

DOCDB simple family (publication)

EP 0239420 A1 19870930; EP 0239420 B1 19920102; AT E71244 T1 19920115; AU 609388 B2 19910502; AU 7067187 A 19871001; CA 1327991 C 19940322; DE 3775588 D1 19920213; JP S63999 A 19880105

DOCDB simple family (application)

EP 87302692 A 19870327; AT 87302692 T 19870327; AU 7067187 A 19870326; CA 532219 A 19870317; DE 3775588 T 19870327; JP 7577687 A 19870328