Patent ID: 10098202

Abstract:
A driver circuit of a light fixture includes a half-bridge inverter, a resonant tank circuit, an isolating transformer, an output rectifier, and a controller. The half-bridge inverter provides an alternating current signal to the resonant tank circuit. The resonant tank circuit includes a resonant inductor, a resonant capacitor, a first clamping diode, and a second clamping diode. The clamping diodes limit the voltage of the resonant capacitor to a power rail voltage and a ground voltage. The isolating transformer is connected to the resonant tank circuit. The controller senses current provided to the light source and adjusts a switching frequency of the half-bridge inverter to maintain the sensed current at a target current. The driver circuit operates as a constant current source with a self-limited output voltage determined as a function of the voltage of the power rail and the turns ration of the isolating transformer.