| 摘要 |
<p>A circuit arrangement according to the invention for high-frequency operation of a discharge lamp (Li) comprises low-frequency rectifying means (LR) for generating a DC voltage (buffer voltage) across first capacitive means (C1) from a low-frequency supply voltage. The circuit arrangement further comprises a DC/AC converter for generating a high-frequency AC voltage from the buffer voltage. A load branch (B) is coupled to the DC/AC converter. The load branch is provided with coupling means (T3, T4) for coupling the discharge lamp (Li) to the load branch. The circuit arrangement further comprises high-frequency rectifying means (HR) for converting a high-frequency voltage generated by the first branch into a DC voltage. The high-frequency rectifying means comprise a series arrangement of first and second unidirectional means (D5, D6) which have the same orientation. The circuit arrangement is furthermore provided with control means (CR) for controlling the power consumed by the discharge lamp (Li) to a level which is dependent on a control signal (Sg). The high-frequency rectifying means further comprise switching means (S3, S3') and further control means (CR1). The switching means shunt at least one of the unidirectional means (D6, D6') of the feedback unit. The further control means control the switching means in a manner which is dependent on the control signal.</p> |
