US Patent No. 10,602,576

OPERATION OF AN ILLUMINANT BY MEANS OF A RESONANT CONVERTER


Patent No. 10,602,576
Issue Date March 24, 2020
Title Operation Of An Illuminant By Means Of A Resonant Converter
Inventorship Christoph Vonach, Dornbirn (AT)
Assignee

Claim of US Patent No. 10,602,576

1. An operating device for loads in the form of an illuminant, comprising:a clocked converter (B), in the form of an LLC circuit, comprising a switching element (20),
a control unit (C) for switching the switching element (20) at an operating frequency, wherein
the operating frequency of the converter (B) is modulated by forward or feedforward control, and wherein a nominal value for the operating frequency is first calculated before the operating frequency of the converter (B) is modulated by forward or feedforward control and wherein the converter (B) is connected to an output of a PFC circuit (A) and is supplied with a bus voltage (Vbus) generated by the PFC circuit (A), wherein an operating frequency of the PFC circuit (A) is frequency-modulated, in a sweep mode, when the bus voltage (Vbus) is a DC voltage and wherein a sweep mode of the LLC circuit is activated if a desired electromagnetic compatibility (EMC) improvement, caused by a ripple of the sweep mode of the PFC circuit, is insufficient, and the sweep mode is selectively provided such that it is connected or amplified only when a low light power is requested and if the ripple in the voltage of the PFC circuit does not itself result in a frequency sweep of the LLC circuit.