Circuit for controlling current to light-emitting diode (LED)

A circuit for controlling current to one or more Light Emitting Diodes (LEDs) with open/shorted LED condition detection, the circuit comprising:

• a DC supply having positive and negative terminals;
• an energy-transferring element connected in series with the positive terminal of the DC supply;
• at least one LED connected in series with the energy transferring element;
• and
• a detection circuit connected between the at least one LED and the negative terminal of the DC supply, the detection circuit comprising
• a first terminal, the first terminal being connected to a first resistor;
• a switching arrangement connected in series with the first resistor;
• and
• a second terminal being connected to the switching arrangement such that the switching arrangement and the first resistor is connected in series between the second and first terminals, wherein the switching arrangement comprises a second resistor, a first switch and a second switch, the second resistor is in series with the second switch and the arrangement of the second resistor and the second switch is in parallel with the first switch, and wherein the switching arrangement is operative such that the first switch is in OFF state and the second switch is in ON state to perform a shorted LED condition test or the first switch is in ON state and the second switch is in OFF state to perform an open LED condition test.