| 摘要 |
The invention relates to a circuit arrangement for operating at least two discharge lamps (La1, La2), comprising - input terminals (K1, K2) for connection to a supply voltage source, - switching means (S1, S2) coupled to the input terminals for generating a high-frequency voltage from a supply voltage delivered by the supply voltage source, - a control circuit (SC) for generating a high-frequency signal for rendering the switching means conducting and non-conducting with high frequency, - a first load branch (I) provided with two ends which are coupled to the switching means, with first inductive means (L1), with first capacitive means (C1), and with terminals (K3, K4) for accommodating a first discharge lamp (La1), - a second load branch (II) provided with two ends which are connected to the ends of the first load branch, with second inductive means (L2), with second capacitive means (C2), and with terminals (K5, K6) for accommodating a second discharge lamp (La2). According to the invention, the circuit arrangement according to the invention is in addition characterized in that the resonance frequency of the first load branch is different from the resonance frequency of the second load branch, in that the frequency of the high-frequency voltage is higher than the lower resonance frequency and lower than the higher resonance frequency, and in that the circuit arrangement is provided with means for adjusting the frequency of the high-frequency voltage. It is achieved thereby that the ratio between the luminous fluxes of the discharge lamps can be controlled in a simple manner.
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