An LED driver that is operable with two different types of power source originally designed for a high-intensity discharge lamp. The LED driver directs current of an input power provided by the power source down a first current path if it is determined that the power source comprises a functional ignitor. The LED driver directs current of an input power provided by the power source down a second current path if it is determined that the 5 power source does not comprise a functional ignitor.

An LED driver that is operable with two different types of power source originally designed for a high-intensity discharge lamp. The LED driver directs current of an input power provided by the power source down a first current path if it is determined that the power source comprises a functional ignitor. The LED driver directs current of an input power provided by the power source down a second current path if it is determined that the 5 power source does not comprise a functional ignitor.

A high-compatibility dimmer circuit is provided, which includes an impedance inspection avoidance module, a dimming module and an alternating-current input module. The impedance inspection avoidance module is connected to a load via an output end. The dimming module is connected to the impedance inspection avoidance module and includes a control unit. The alternating-current input module is connected to the dimming module, and converts an input alternating voltage into a pulsating direct voltage so as to power the load and the dimming module. When the load is driven, the control unit starts timing and switches the impedance inspection avoidance module after a predetermined time period. In this way, the dimming module can directly power the load and perform dimming for the load according to a dimming signal.

A new lighting fixture electronics design is disclosed that is particularly useful for lighting fixtures to utilize energy either directly from the traditional AC power grid or from locally generated renewable DC power sources. The invention entails improvement to the traditional LED driver or lighting ballast design to be able to additionally accept local DC microgrid power directly, without the need to pass the DC power through an external inverter to create an AC voltage. In this way, building construction can be commenced with a single lighting fixture that is capable to operate in multiple input modes, receiving power either from the AC grid or a DC grid, without the need for additional expense required to update the circuitry of the lighting fixtures in the building when the building is upfit at a future date with local renewable energy generating devices.

A new lighting fixture electronics design is disclosed that is particularly useful for lighting fixtures to utilize energy either directly from the traditional AC power grid or from locally generated renewable DC power sources. The invention entails improvement to the traditional LED driver or lighting ballast design to be able to additionally accept local DC microgrid power directly, without the need to pass the DC power through an external inverter to create an AC voltage. In this way, building construction can be commenced with a single lighting fixture that is capable to operate in multiple input modes, receiving power either from the AC grid or a DC grid, without the need for additional expense required to update the circuitry of the lighting fixtures in the building when the building is upfit at a future date with local renewable energy generating devices.

An illumination power circuit with a dimming function and an associated control method thereof are provided, where the illumination power circuit includes a first conversion circuit, a digital controller and a second conversion circuit. The first conversion circuit converts a first analog dimming signal from an analog dimmer into a first digital dimming signal, where the analog dimmer generates the first analog dimming signal according to operations of a user, to allow the user to manually control brightness of an illumination device. The digital controller receives the first digital dimming signal and a control signal from a computer, and generates at least one final dimming signal according to the first digital dimming signal and the control signal. In addition, the second conversion circuit generates a direct current output signal according to the final dimming signal, for driving the illumination device.

An illumination power circuit with a dimming function and an associated control method thereof are provided, where the illumination power circuit includes a first conversion circuit, a digital controller and a second conversion circuit. The first conversion circuit converts a first analog dimming signal from an analog dimmer into a first digital dimming signal, where the analog dimmer generates the first analog dimming signal according to operations of a user, to allow the user to manually control brightness of an illumination device. The digital controller receives the first digital dimming signal and a control signal from a computer, and generates at least one final dimming signal according to the first digital dimming signal and the control signal. In addition, the second conversion circuit generates a direct current output signal according to the final dimming signal, for driving the illumination device.

A light emitting diode (LED) device is provided. The LED device a first LED string configured to emit light having a first color temperature; a second LED string connected to the first LED string in parallel, and configured to emit light having a second color temperature different from the first color temperature; a controller configured to generate a control signal based on a control command received from an external controller; a switching circuit configured to control brightness of any one or any combination of the first LED string and the second LED string based on the control signal; and a power supply configured to generate an internal power voltage for operation of the controller and the switching circuit.

A resonant inverter has a switch network from which a phase signal is provided representing the phase of the switching signal. A resonant tank circuit is coupled to the first switch network output and provides a feedback signal comprising a resonance voltage across a circuit element of the resonant tank circuit. A reference current to be drawn from the input node is set and a reference phase is set based on the reference current. The switching signal for the switch network is controlled based on a phase difference between the resonance voltage and the phase signal, and based on the reference phase. This resonant inverter employs a phase modulation scheme as the control scheme for the switch network of a resonant inverter. This approach is suited for high and very high frequency operation of resonant converters, for example up to tens of MHz.

A resonant inverter has a switch network from which a phase signal is provided representing the phase of the switching signal. A resonant tank circuit is coupled to the first switch network output and provides a feedback signal comprising a resonance voltage across a circuit element of the resonant tank circuit. A reference current to be drawn from the input node is set and a reference phase is set based on the reference current. The switching signal for the switch network is controlled based on a phase difference between the resonance voltage and the phase signal, and based on the reference phase. This resonant inverter employs a phase modulation scheme as the control scheme for the switch network of a resonant inverter. This approach is suited for high and very high frequency operation of resonant converters, for example up to tens of MHz.