CPC H05B 45/3574 (2020.01) [H05B 45/305 (2020.01); H05B 45/3725 (2020.01)] | 24 Claims |
1. An LED lamp for use in a luminaire, the LED lamp comprising:
a plurality of LEDs connected in a plurality of groups;
one or more rectifier circuits adapted for rectifying an electrical current received from the luminaire for supply to the LEDs;
a first control circuit adapted to estimate electrical current or electrical power received by or used by the LED lamp, and adapted to generate an output on the basis of the estimate; and
a switching circuit comprising a first switch for switching the plurality of groups of LEDs between a plurality of different circuit configurations at a switching frequency of at least 300 kHz and according to a duty cycle;
wherein the switching circuit is configured to adjust the duty cycle in dependence on the output of the first control circuit to adjust the electrical power used by the LED lamp.
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