3-Way Phase-Cut Dimmable LED Driver Circuit

The LED driver circuit is designed to perform multiple functions: it can operate with conventional three-way dimming socket switches, phase-cut dimmer controls, and standalone dimming. The circuit includes a three-way switch sensing circuit that detects switch positions and adjusts lamp current accordingly, while also including phase-cut sensing circuitry that detects the average value of the phase-cut power line to adjust lamp current. This multi-functionality allows the same driver to work with different dimming control methods without requiring separate circuits for each application.

The patent introduces intermediary sensing circuits that mediate between the external three-way switch and the LED driver control. The three-way switch sensing circuit includes circuitry to sense the position of the three-way switch and changes the lamp current accordingly. The phase-cut sensing circuitry includes circuitry to sense the average value of a phase-cut power line to adjust lamp current. These intermediary sensing circuits translate external switch positions and phase-cut signals into appropriate control signals for the LED driver, enabling compatibility without directly complicating the core LED driving function.

The patent merges the three-way switch sensing function and phase-cut sensing function into a single integrated LED driver circuit. Both sensing circuits share common components such as the rectifier circuit with three AC inputs, the power switch, and the PWM controller. The circuit combines multiple sensing capabilities (three-way switch position detection and phase-cut power line detection) into one unified driver architecture, allowing seamless integration with existing dimming technologies while avoiding the need for separate independent circuits for each dimming method.