| 摘要 |
<p>The invention relates to a circuit arrangement for operating a lamp (LA), provided with input terminals (K1, K2) for connection to a supply voltage source which delivers a low-frequency AC voltage, rectifying means (D1-D4) coupled to the input terminals for rectifying the low-frequency AC voltage and provided with output terminals (K3, K4), a first branch comprising a series arrangement of a breakdown element (X1) and first capacitive means (C1) and interconnecting the output terminals, and a second branch shunting the first capacitive means for discharging said first capacitive means. According to the invention, the circuit arrangement is in addition provided with further capacitive means (C2) across which a DC voltage is present during lamp operation, with which voltage the lamp is supplied, a DC-DC converter (L1, D5, S1, Sc) coupled to the output terminals and the further capacitive means, and a third branch comprising a series arrangement of diode means (D6) and the further capacitive means and shunting the first capacitive means. It is achieved thereby that the DC voltage across the further capacitive means does not rise or rises only slightly in the case of two transients in quick succession or a transient having a comparatively high amplitude or a comparatively long duration.</p> |
