US7045973B2
Expired / Lapsed
US
⏱️ 0.0 years remaining
Operating circuit for a dielectrically impeded discharge lamp having an overvoltage protection circuit
Assignee: Osram GmbH
•
Filing: 2004-10-14
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Granted: 2006-05-16
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Expires: 2024-10-14
Abstract
Abstract The invention relates to a method and a circuit for starting or operating discharge lamps which are designed for dielectrically impeded discharges. In this case, it is established in advance, with the aid of an overvoltage protection circuit and test power pulses, whether the discharge lamp is connected.
Inventors
- 👤 Oskar Schallmoser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:12
CPC Classifications
H; H05; H05B; H05B41/00; H05B41/14; H05B41/26; H05B41/24; H05B41/28; H05B41/288; H05B41/292
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
158 words
An operating circuit for a dielectrically impeded discharge lamp having an inductive converter for inputting power to the lamp, a switching transistor in a line supplying current to the converter, and an overvoltage protection circuit for detecting a voltage across the switching transistor and preventing lamp operation if a voltage which is above a predetermined threshold value is detected, in order to prevent the switching transistor being destroyed by energy input from the converter in the event of a lamp being absent, and the operating circuit being designed to apply, when restarting lamp operation, initially at least one test power pulse to the converter which is so small that destruction of the switching transistor as a result of this test power pulse is ruled out, and the overvoltage protection circuit responds to a voltage, produced by this test power pulse, across the switching transistor when no lamp is connected and does not respond when the lamp is connected.
Claim 2
Dependent Claim
158 words
An operating circuit for a dielectrically impeded discharge lamp having an inductive converter for inputting power to the lamp, a switching transistor in a line supplying current to the converter, and an overvoltage protection circuit for detecting a voltage across the switching transistor and preventing lamp operation if a voltage which is above a predetermined threshold value is detected, in order to prevent the switching transistor being destroyed by energy input from the converter in the event of a lamp being absent, and the operating circuit being designed to apply, when restarting lamp operation, initially at least one test power pulse to the converter which is so small that destruction of the switching transistor as a result of this test power pulse is ruled out, and the overvoltage protection circuit responds to a voltage, produced by this test power pulse, across the switching transistor when no lamp is connected and does not respond when the lamp is connected.
Claim 3
Dependent Claim
19 words
The operating circuit as claimed in claim 1 , in which the converter operates using the flyback converter principle.
Claim 4
Dependent Claim
21 words
The operating circuit as claimed in claim 1 , having a monoflop for driving the control input of the switching transistor.
Claim 5
Dependent Claim
40 words
The operating circuit as claimed in claim 1 , having a comparator for comparing the current through the switching transistor with a reference value, in which the size of the test power pulse is established by setting the reference value.
Claim 6
Dependent Claim
16 words
The operating circuit as claimed in claim 4 having a microcontroller which sets the reference value.
Claim 7
Dependent Claim
15 words
The operating circuit as claimed in claim 1 having a microcontroller which clocks the converter.
Claim 8
Dependent Claim
23 words
The operating circuit as claimed in claim 3 , in which the microcontroller clocks the converter via an enable input of the monoflop.
Claim 9
Dependent Claim
23 words
The operating circuit as claimed in claim 1 , in which the overvoltage protection circuit has a peak-value rectifier having a low-pass characteristic.
Claim 10
Dependent Claim
19 words
A lighting system comprising an operating circuit as claimed in claim 1 and a suitable dielectrically impeded discharge lamp.
Claim 11
Dependent Claim
17 words
The lighting system as claimed in claim 9 , in which the lamp is a flat radiator.
Claim 12
Dependent Claim
22 words
The lighting system as claimed in claim 10 , in which the flat radiator has a surface diagonal of at least 20″.
Claim 13
Dependent Claim
18 words
A monitor having the lighting system as claimed in claim 1 for the purpose of back-lighting the monitor.
Claim 14
Dependent Claim
19 words
A method for starting a dielectrically impeded discharge lamp having the operating circuit as claimed in claim 1 .
Claim 15
Dependent Claim
23 words
The operating circuit as claimed in claim 6 , in which the microcontroller clocks the converter via an enable input of the monoflop.
References Cited (Backward Citations)
US4350935A
Cited
US5982106A
Cited
US6274987B1
Cited
US6011358A
Cited
US6198231B1
Cited
US6781326B2
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2009-05-15 | 2009-11-14 | 2010-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2013-05-15 | 2013-11-14 | 2014-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2017-05-15 | 2017-11-14 | 2018-05-16 | $7700.00 | Window Closed / Lapsed |