EP 0580255 B1 19971217 - DC-AC converter with protection means, for supplying a discharge lamp
Title (en)
DC-AC converter with protection means, for supplying a discharge lamp
Title (de)
Geschützter Umrichter zur Steuerung einer Entladungslampe
Title (fr)
Onduleur avec circuit de protection, pour alimenter une lampe à décharge
Publication
Application
Priority
- EP 93202157 A 19930713
- EP 92202205 A 19920720
Abstract (en)
[origin: EP0580255A1] The invention relates to a circuit arrangement for igniting and operating a discharge lamp, which arrangement comprises a DC-AC converter provided with comprising at least one switching element (S1,S2) for generating a current with alternating polarity by being conducting and non-conducting with a frequency f and a branch A provided with terminals (1,2) suitable for being connected to a DC voltage source, a load branch B comprising inductive means (L1), capacitive means (C4,C5,C9), and means (L2) for coupling the discharge lamp to the load branch B, a control circuit for rendering the switching element (S1,S2) conducting and non-conducting with the frequency f, comprising a resonant circuit which comprises further inductive means (L2) and further capacitive means (C2). According to the invention, the circuit arrangement is also provided with means for limiting an ignition voltage, which means comprise a branch C coupled to the resonant circuit and comprising a series arrangement of a frequency-dependent impedance (L7) and a semiconductor element (T) provided with a control electrode for influencing the impedance of the semiconductor element in dependence on a potential at the control electrode, a branch D coupled to the load branch and to the control electrode of the semiconductor element for influencing the potential of the control electrode in dependence on the voltage across the discharge lamp. An effective limitation of voltages and currents in the circuit arrangement during ignition of the discharge lamp is realised thereby. <IMAGE>
IPC 1-7
IPC 8 full level
H05B 41/285 (2006.01)
CPC (source: EP)
H05B 41/2856 (2013.01)
Designated contracting state (EPC)
BE DE ES FR GB IT NL
DOCDB simple family (publication)
DOCDB simple family (application)
EP 93202157 A 19930713