Device and method for preheating the coil electrodes of a fluorescent lamp
AssigneePatent-Treuhand-Gesellschaft fuer elektrische Gluehlampen mbH
InventorWolfram Sowa
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Abstract
The present invention relates to a device for preheating the two coil electrodes (W1, W2) of a fluorescent lamp (La) comprising an AC voltage source (10), a resonance capacitor CR, which is arranged serially between the two coil electrodes (W1, W2), a first inductance (L1), which is coupled between the AC voltage source (10) and one of the two coil electrodes (W1, W2), and a second inductance (L2), which is connected to a point between the AC voltage source (10) and the coil electrode (W1) coupled thereto, the second inductance (L2) being coupled to the first inductance (L1) in such a way that a current flow (IL2) through the second inductance (L2) leads to a reduction of the magnetization of the first inductance (L1). It furthermore relates to a corresponding method.
Claims6
A device for preheating the two coil electrodes (W1, W2) of a fluorescent lamp (La), comprising;
- an AC voltage source (10):
- a resonance capacitor CR, which is arranged serially between the two coil electrodes (W1, W2);
- a first inductance (L1), which is counted between the AC voltage source (10) and one of the two coil electrodes (W1, W2);
- characterized in that it furthermore comprises:
- a second inductance (L2), which is connected to a point between the AC voltage source (10) and the coil electrode (W1) coupled thereto, the second inductance (L2) being coupled to the first inductance (L1) in such a way that a current flow (IL2) through the second inductance (L2) leads to a reduction of the magnetization of the first inductance (L1) wherein the other connection of the second inductance (L2) is connected to ground.
A device for preheating first and second coil electrodes (W1, W2) of a fluorescent lamp (La) comprising:
- an AC voltage source (10);
- a first inductance (L1) coupled between the AC voltage source (10) and the first coil electrode (W1);
- a resonance capacitor (CR) coupled between the first and second coil electrodes (W1, W2);
- a series circuit coupled between the first coil electrode (W1) and ground, the series circuit comprising:
- a second inductance (L2) magnetically coupled to the first inductance (L1);
- and
- a control device (B1) for controlling a current flow (IL2) through the second inductance (L2).
A method for preheating first and second coil electrodes (W1, W2) of a fluorescent lamp (La), using a preheating device having an AC voltage source (10), a first inductance (L1) coupled between the AC voltage source (10) and the first coil electrode (W1), a resonance capacitor (CR) coupled between the first and second coil electrodes (W1, W2), and a series circuit coupled between the first coil electrode (W1) and ground, the series circuit comprising a second inductance (L2) and a control device (B1), the method comprising the steps of:
- a) coupling the second inductance (L2) to the first inductance (L1) such that a current flow (IL2) through the second inductance (L2) leads to a reduction in a current flow (IL1) through the first inductance (L1);
- b) effecting a current flow (IL2) through the second inductance (L2) during preheating;
- and
- c) preventing a current flow (IL2) through the second inductance (L2) after preheating.
Dependencies are inferred from the claim text.