Patent ID: 9301354
Filing Date: 2016-03-29
CPC Classification: H05B,Y02B

Claim Text:
1. An interface circuit for operating a light source, equipped with input terminals for connection to lamp connection terminals of an electronic fluorescent lamp driver, a first string, conductively interconnecting a first pair of input terminals, a second string, conductively interconnecting a second pair of input terminals, a third string, conductively interconnecting a first terminal of the first string and a second terminal of the second string, wherein the third string comprises a rectifier, output terminals of said rectifier being coupled, during operation, to the light source, and a first switching element for controlling the conductive state of the third string, such that the third string delivers a driving current to the light source when the first switching element is conductive, a fourth string coupled to the third string and comprising a sensor circuit, having an output terminal coupled to a control electrode of the first switching element, for sensing the amplitude of a high frequency AC voltage between the first and the second terminal and for rendering the first switching element conductive when the amplitude of the high frequency AC voltage reaches a predetermined value.