System and method for implementing mains-signal-based dimming of solid state lighting module

A method of providing mains-signal-based dimming of a light-emitting diode (LED) module, the method comprising:

• generating a mains sensing signal indicating amplitude of a rectified mains voltage from a primary side circuit, connected to a primary side of a power transformer;
• transmitting the mains sensing signal across an isolation barrier corresponding to the power transformer;
• generating a dimming feedback signal in a secondary side circuit, connected to a secondary side of the power transformer, based at least in part on the transmitted mains sensing signal;
• transmitting the dimming feedback signal from the secondary side circuit across the isolation barrier to the primary side circuit;
• and
• adjusting a drive current of the LED module output by the secondary side circuit based on the dimming feedback signal transmitted to the primary side circuit.

A mains-signal-based driver for dimming a light-emitting diode (LED) module, the driver comprising:

• a transformer having a primary side and a secondary side;
• a primary side circuit connected to the primary side of the transformer, the primary side circuit comprising a voltage rectifier configured to rectify a dimmed mains voltage;
• a secondary side circuit connected to the secondary side of the transformer and configured to output a drive current for driving the LED module, the secondary side circuit comprising an output current control, wherein the secondary side circuit is separated from the primary side circuit by an isolation barrier;
• and
• a dimming control circuit comprising a mains sensing circuit configured to generate a mains sense signal indicating amplitude of the rectified mains voltage;
• an optical isolator configured to provide electrical coupling across the isolation barrier;
• and a microprocessor configured to receive the mains sense signal from the mains sensing circuit via the optical isolator, to generate a current reference signal in response to the mains sense signal and to output the current reference signal to the output current control,
• wherein the output current control generates a dimming feedback signal based on a comparison of the current reference signal and the drive current, and transmits the dimming feedback signal to the primary side circuit across the isolation barrier, and
• wherein the primary side circuit adjusts an input to the transformer in response to the dimming feedback signal, thereby adjusting the drive current in the secondary side circuit.