Solid-State Lighting With Reduced Light Flickering

A light-emitting diode (LED) luminaire, comprising:

• one or more LED arrays;
• at least one full-wave rectifier configured to couple to alternate-current (AC) mains and convert a line voltage from the AC mains into a first direct-current (DC) voltage;
• a buck circuit with a switching portion comprising a first control device, a primary diode circuit, a first electronic switch controlled by the first control device and configured to modulate the first DC voltage into a variable DC voltage at a switching frequency, a transformer comprising a primary winding and a secondary winding, and a first ground reference;
• and
• an LED driving circuit comprising a second ground reference electrically isolated from the first ground reference, a feedback control circuit, and a first rectifier circuit and a second rectifier circuit both coupled to the secondary winding, wherein the first rectifier circuit and the second rectifier circuit are respectively configured to convert the variable DC voltage into a second DC voltage and a third DC voltage via the transformer, wherein the second DC voltage is configured to produce a feedback control signal transmitted to the first control device via the feedback control circuit, and wherein the third DC voltage is configured to drive the one or more LED arrays with a flicker-reduced light emission,
• wherein:
• the feedback control circuit comprises an optocoupler circuit comprising an LED and a photo-transistor optically coupled to the LED,
• the LED comprises a cathode and is configured to convert the feedback control signal into a light signal,
• the photo-transistor is configured to convert the light signal into an electric signal, and
• the optocoupler circuit is configured to provide an electrical isolation between the buck circuit with the switching portion and the LED driving circuit but to allow the feedback control signal to transmit.