| 摘要 |
In order to be able to control the brightness of even fluorescent lamps with an increased starting voltage (for example lamps with a diameter of 26 mm) without flickering using a normal dimmer circuit, the additional arrangement of a radio-frequency generator (7) is proposed, which generator has the mains AC voltage applied to it on the input side via the dimmer (5) and, on the output side, emits a radio-frequency AC voltage to the electrodes (4a, b; 15a, b) of the fluorescent lamps (1, 12). The amplitude of the radio-frequency AC voltage depends on the internal impedance of the gas-discharge paths of the fluorescent lamps and hence on the switching state of the controllable semiconductor component of the dimmer (5). The radio-frequency generator (7) in this case consists of the series circuit of a switching-on delay element (8) on the input side, a frequency converter (9), a transformer (10), and coupling capacitors (11, 16) on the output side. <IMAGE>
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