Patent ID: 8274237

Claim:
An LED driver circuit comprising: a current control circuit configured to receive an input signal from a power source and to provide a current output for powering one or more LEDs; a voltage sensor configured to detect a voltage across the LED; an LED current restriction circuit configured to restrict a current flow into the LED; a short circuit response circuit configured to control the LED current restriction circuit dependent on a comparison between the voltage detected by the voltage sensor and a predetermined threshold value; wherein the short circuit response circuit controls the LED current restriction circuit so as to restrict a current flowing into the LED upon determining the voltage detected by the voltage sensor is equal to or less than the predetermined threshold value; and wherein the LED current restriction circuit comprises a first switching element connected in series with the LED, and the current control circuit comprises a power converter further comprising a second switching element, a switch driver circuit and a switch driver control circuit, the switch driver circuit configured to control a current output supplied to the LED by driving the second switching element in response to a voltage provided by the voltage sensor to the switch driver control circuit.