Method and control circuit for starting a gas-discharge lamp
AssigneeAutomotive Lighting Reutlingen GmbH
InventorsPeter Kluetz, Ruediger Laubenstein, Christian Johann, Bjoern Moosmann, Michael Herrmann, Matthias Roder
Life of this patent
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Abstract
A method operates a gas-discharge lamp (16) in a transition from a “deactivated” state without an electric arc to a stable “light-generating” state. The method comprises steps of discharging a booster capacitor (C2) in an “acquisition” phase following an ignition-voltage impulse via a current path that conducts a current flowing through the gas-discharge lamp (16) and in which an inductor (L1) having at least one switch (S5) lies in series and cyclically discharging the booster capacitor (C2) by a repeated alternating closing and opening of the switch (S5).
Claims12
A method for operating a gas-discharge lamp (16) in a transition from a “deactivated” state without an electric arc to a stable “light-generating” state, the method comprising steps of:
- discharging a booster capacitor (C2) in an “acquisition” phase following an ignition-voltage impulse via a discharge current path that conducts a current flowing from the gas-discharge lamp (16) through a circuit branch comprising an inductor (L1), the booster capacitor (C2) and at least one switch (S5) disposed in series with one another;
- and
- cyclically discharging the booster capacitor (C2) by a repeated alternating closing and opening of the switch (S5), wherein a level of discharge current is measured and the switch (S5) is then opened if the level exceeds a predetermined first “threshold” value and is closed if the level falls below a predetermined second “threshold” value.
A control circuit (10) equipped for operation of a gas-discharge lamp (16) in a transition from a “deactivated” state without an electric arc to a stable “light-generating” state, the control circuit comprising:
- a booster capacitor (C2) that is adapted to be discharged in an “acquisition” phase following an ignition-voltage impulse via a discharge current path that conducts a current flowing from the gas-discharge lamp (16) through a circuit branch comprising an inductor (L1), the booster capacitor (C2) and at least one switch (S5) disposed in series with one another, said booster capacitor being cyclically discharged by a repeated alternating closing and opening of the switch (S5), wherein the control circuit is adapted to measure a level of a discharge current and to open the switch (S5) if the level exceeds a predetermined first “threshold” value and to close said switch if the level falls below a predetermined second “threshold” value.
Dependencies are inferred from the claim text.