Short Circuit Detection for Lighting Circuits

A method of detecting a fault condition within a plurality of LED circuits of a lighting system comprising the steps of:

• determining a feedback voltage for each of the LED circuits of the plurality of LED circuits;
• causing regulation of a drive voltage to power the plurality of LED circuits based on the plurality of feedback voltages;
• determining a fault circuit having a fault condition among the plurality of LED circuits for which the respective feedback voltage of the respective LED circuit is below a first fault condition threshold;
• applying a test voltage to a cathode of a LED of the determined fault circuit having a fault condition;
• and
• determining if the feedback voltage of the determined fault circuit having the fault condition remains below or exceeds a second fault circuit condition threshold after the test voltage is applied to the cathode of the determined fault circuit having a fault condition threshold.

A method of detecting a pre start fault condition within a plurality of LED circuits of a lighting system comprising the steps of:

• determining a feedback voltage for each of the LED circuits of the plurality of LED circuits;
• causing regulation of a drive voltage to power the plurality of LED circuits based on the plurality of feedback voltages;
• determining a fault circuit having a fault condition among the plurality of LED circuits for which the respective feedback voltage of the respective LED circuit is below a first fault condition threshold;
• applying a test voltage to a cathode of a LED of the determined fault circuit having a fault condition;
• determining if the feedback voltage of the determined fault circuit having the fault condition remains below or exceeds a second fault circuit condition threshold after the test voltage is applied to the cathode of the determined fault circuit having a fault condition threshold, wherein the fault circuit has a short circuit condition if the feedback voltage of the determined fault circuit remains below a second fault circuit detection threshold;
• determining the fault circuit as having an open circuit condition if the feedback voltage of the fault circuit exceeds the second fault circuit condition threshold after the test voltage has been applied to the cathode of the LED in the fault circuit;
• and
• determining the fault circuit as having a short circuit condition if the feedback voltage of the fault circuit is less than the second fault circuit condition threshold after the test voltage has been applied to the cathode of the LED in the fault circuit.

A lighting system comprising:

• a plurality of LED circuits;
• a controllable power source;
• and
• a controller wherein the controller can detect LED short circuits and/or LED open circuits.