EP0198536A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Adaption circuit for operating a high-pressure discharge lamp
Assignee: Koninklijke Philips NV
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Filing: 1986-04-03
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Granted: —
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Expires: 2006-04-03
Abstract
Abstract The invention relates to an adaptation circuit (3) for operating a high-pressure discharge lamp (1) via a controlled semiconductor switch (4) in series with the lamp (1). The control circuit for the switch (4) is constituted by a voltage division circuit (5, 6). According to the invention, the voltage division circuit (5, 6) is connected in parallel with the switch (4) in the state in which the lamp (1) is connected and one branch of the voltage division circuit (5, 6) comprises a parallel-combination of a capacitor (57) and a resistor (56). Thus, it is achieved that the variation of the voltage across the lamp (1) influences the control of the semiconductor switch (4), while it proves to be possible to stabilize for the major part the power dissipated by the lamp (1) against variation in the supply voltage and against lamp voltage variations during the life of the lamp.
Inventors
- 👤 Johny Armand Josephina Daniels
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-10 02:10
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/16; H05B41/20; H05B41/23; H05B41/231; Y; Y10; Y10S; Y10S315/00; Y10S315/07
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
151 words
An adaptation circuit for operating abigh-pressure discharge lamp provided with a first and a second input terminal intended for connection of a supply source and with a first and a second output terminal intended for connection of a high-pressure discharge vessel of the high-pressure discharge lamp, each input terminal being connected to the respective output terminal, while the connection between the first input terminal and the first output terminal includes a first controlled semiconductor switch, of which a control electrode isconnected to a junction between a first and a second branch of a voltage division circuit, which at least in the case of a connected lamp is arranged in parallel to the first semiconductor switch, characterized in that the first branch of the voltage division circuit comprises a voltage source dependent upon the lamp voltage, of which the voltage has the same polarity as the voltage across the voltage division circuit.
Claim 2
Dependent Claim
151 words
An adaptation circuit for operating abigh-pressure discharge lamp provided with a first and a second input terminal intended for connection of a supply source and with a first and a second output terminal intended for connection of a high-pressure discharge vessel of the high-pressure discharge lamp, each input terminal being connected to the respective output terminal, while the connection between the first input terminal and the first output terminal includes a first controlled semiconductor switch, of which a control electrode isconnected to a junction between a first and a second branch of a voltage division circuit, which at least in the case of a connected lamp is arranged in parallel to the first semiconductor switch, characterized in that the first branch of the voltage division circuit comprises a voltage source dependent upon the lamp voltage, of which the voltage has the same polarity as the voltage across the voltage division circuit.
Claim 3
Dependent Claim
41 words
2 An adaptation circuit as claimed in Claim 1, characterized in that the voltage source dependent upon the lamp voltage is composed of a parallel-combination of a capacitor and a resistor, this voltage source being connected to the second output terminal.
Claim 4
Dependent Claim
53 words
A circuit as claimed in Claim 1 or 2, suitable to be operated at a supply voltage having periodically changing polarities, characterized in that at least the parallel-combination is connected to direct voltage terminals of a rectifier bridge, while two alternating voltage terminals of this bridge are included in the voltage division circuit.
Claim 5
Dependent Claim
48 words
A circuit as claimed in Claim 3, characterized in that the rectifier bridge is provided with a third alternating voltage terminal and in that the third alternating voltage terminal forms part of the connection between the voltage source dependent upon the lamp voltage and the second output terminal.
Claim 6
Dependent Claim
26 words
A circuit as claimed in Claim 2, 3 or 4, characterized in that the connection between the parallel-combination and the second output terminal includes a resistor.
Claim 7
Dependent Claim
39 words
A circuit as claimed in Claim 2, 3, 4 or 5, characterized in that the connection between the parallel-combination and the second output terminal includes a switch, which is closed only in case the first semiconductor switch is closed
Claim 8
Dependent Claim
30 words
A circuit as claimed in Claim 6, characterized in that the switch is a second controlled semiconductor switch, of which a control electrode is connected to the first output terminal.
References Cited (Backward Citations)
US3694692A
Cited
US4323821A
Cited
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