Pulse modulation for isolated auxiliary voltage and dimming signal transfer over single opto-isolator

A circuit configured to:

• generate a signal comprising first information and second information,
• wherein the first information comprises a desired LED brightness, and
• wherein the second information comprises an output voltage of an auxiliary transformer winding;
• and
• transmit the signal to a controller over a galvanic isolation barrier such that the first information comprising the desired LED brightness is transmitted over the galvanic isolation barrier via the signal and the second information comprising the output voltage of the auxiliary transformer winding is also transmitted over the galvanic isolation barrier via the signal.

A system comprising:

• a primary transformer winding;
• an opto-isolator;
• a primary side circuit configured to provide a current to the primary transformer winding;
• a load comprising one or more light-emitting diodes (LEDs), wherein the load is configured to be powered by a secondary transformer winding;
• a circuit configured to be powered by an auxiliary transformer winding, wherein the circuit comprises:
• a regulator configured to stabilize an output voltage of the auxiliary transformer winding, and
• a pulse-width modulator configured to accept first information and second information, and produce a signal comprising the first information and the second information;
• and
• a controller,
• wherein the first information comprises a desired LED brightness,
• wherein the second information comprises an output voltage of the auxiliary transformer winding,
• wherein the pulse-width modulator is configured to transmit the signal to the controller via the opto-isolator, and
• wherein the controller is configured to:
• process the signal, and
• regulate the power transfer to the secondary transformer winding and to the auxiliary transformer winding.