Patent ID: 9240726
Filing Date: 2016-01-19
CPC Classification: H02M,H05B,Y02B

Claim Text:
1. A driver circuit configured to provide a current to a load, the driver circuit comprising: a half-bridge inverter having an input configured to connect to a direct current (DC) power rail, an output, and a circuit ground; a resonant tank circuit having an input connected to the output of the half-bridge inverter and an output; an output transformer having an input connected to the output of the resonant tank circuit; a rectifier connected between the output transformer and the load; a variable capacitance circuit connected between the output of the half-bridge inverter and the circuit ground of the half-bridge inverter, wherein the variable capacitance circuit is configured to vary a capacitance of the variable capacitance circuit as a function of a control signal; the rectifier has an output ground isolated from the circuit ground of the half-bridge inverter by the output transformer; the driver circuit further comprises a dimming controller configured to receive a dimming signal and provide the control signal to the variable capacitance circuit as a function of the received dimming signal; the dimming controller is referenced to the output ground of the rectifier; and the variable capacitance circuit comprises