| 摘要 |
The invention relates to an LED converter for operating a load comprising at least one LED series that includes at least one LED, preferably multiple LEDs. On the primary side, the LED converter comprises a resonant converter supplied with a direct current voltage. The resonant converter has a half-bridge that is constructed of two reciprocally clocked switches and that provides a supply voltage for the LED series through a serial/parallel resonance circuit connected to the midpoint of said half-bridge. To regulate the power transferred by the LED converter to the LED series as a feedback factor in each switch-on cycle, a control unit is designed to directly or indirectly determine a peak value of the feedback factor through the lower-potential switch of the half-bridge and to adjust the clocking of the half-bridge, i.e. the frequency and/or the duty factor, as a control factor. |
| 主权项 |
1. An LED converter (10) for operating a load comprising at least one LED string (6) having at least one LED, wherein the LED converter (10) comprises, on a primary side, a resonant converter (1) to which a DC voltage (Vbus) is supplied, and which has a half-bridge formed with two alternately clocked switches (S1, S2), said half-bridge provides a supply voltage for the LED string (6) via a series/parallel resonant circuit connected to the center point of said half-bridge, wherein a control unit (2), for regulating the power transmitted by the LED converter (10) to the LED string, is configured to determine directly or indirectly a peak value (Max) of a current (Isense) through a lower-potential switch (S1) of the half-bridge, as actual value fed back in each switch-on cycle of the lower-potential switch (S1), and to set, as controlled variable, a frequency (fsw) of a clocking and/or a duty factor, of the half-bridge. |
