Self-exciting step-up converter
AssigneeOsram Gesellschaft Mit Beschraenkter Haftung
InventorsKlaus Fischer, Josef Kreittmayr
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Abstract
An electronic ballast includes a step-up converter, which includes a storage inductor, a diode, an intermediate circuit condenser and a switch element. According to the invention, a current passing through the storage inductor is used in the form of an indicator of turnon and turnoff times of the step-up converter oscillates in a self-exciting manner.
Claims19
An electronic ballast for a discharge lamp with a step-up converter (L, D1, T1, C2), which has a storage inductor (L), a diode (D1), an intermediate circuit capacitor (C2) and a switching element (T1), characterized in that it is designed
- to switch off the switching element (T1) in the step-up converter (L, D1, T1, C2) when a maximum current value of the current flowing through the switching element (T1) is reached, and
- to switch on the switching element (T1) by means of a jump in the potential (V2) between the storage inductor (L) and the diode (D1) after demagnetization of the storage inductor (L),
- so that the step-up converter (L, D1, T1, C2) oscillates in self-excited fashion.
A method for operating an electronic ballast for a lamp with a step-up converter (L, D1, T1, C2), which has a storage inductor (L), a diode (D1), an intermediate circuit capacitor (C2) and a switching element (T1), characterized in that
- the switching element (T1) in the step-up converter (L, D1, T1, C2) is switched off when a maximum current value of the current flowing through the switching element (T1) is reached, and
- the switching element (T1) is switched on by a jump in the potential (V2) between the storage inductor (L) and the diode (D1) after the demagnetization of the storage inductor (L),
- so that the step-up converter (L, D1, T1, C2) oscillates in self-excited fashion.
Dependencies are inferred from the claim text.