US 9,814,113 B2
Voltage converter for operating lamps
Thomas Ondrisek, Vienna (AT); and Klaus Mündle, Feldkirch (AT)
Assigned to Tridonic GmbH & Co KG, (AT)
Appl. No. 15/117,781
Filed by TRIDONIC GMBH & CO KG, Dornbirn (AT)
PCT Filed Jan. 14, 2015, PCT No. PCT/EP2015/050533
§ 371(c)(1), (2) Date Aug. 10, 2016,
PCT Pub. No. WO2015/117797, PCT Pub. Date Aug. 13, 2015.
Claims priority of application No. 10 2014 202 363 (DE), filed on Feb. 10, 2014.
Prior Publication US 2016/0353541 A1, Dec. 1, 2016
Int. Cl. H05B 33/08 (2006.01)
CPC H05B 33/0851 (2013.01) [H05B 33/0812 (2013.01)] 16 Claims
OG exemplary drawing
 
1. An operating device for one or more LED strips comprising a voltage converter that outputs a DC output voltage to operate the one or more LED strips and a control unit that controls operation of the voltage converter, wherein the operating device is configured to implement the following steps:
a) output a DC output voltage (Vout) from the voltage converter increasing and decreasing at least once in a voltage range lying above a flux voltage of the one or more LED strips (1) to artificially modulate the DC output voltage, while measuring an LED current (iL),
b) calculate a gradient of the impedance of the one or more LED strips (1) in the control unit by calculating a change in measured LED current (iL) with respect to a respective change in DC voltage (Vout) by a regression method; and
c) compare the calculated gradient of impedance to a reference value in the control unit, and lower the operating point of the DC voltage (Vout) if the gradient is less than the reference value and raise the operating point if the gradient is greater than the reference value.