Abstract:
A light emitting diode (LED) driver includes an inverter for converting a DC input signal to a pulsating signal. A multiple output multi-resonant converter generates a first LED string current in response to the pulsating signal, and also generates a second LED string current in response to the pulsating signal. A transistor that may be a FET or BJT operating in its linear region regulates the second LED string current independent of the first LED string current without sacrificing efficiency of the overall power train.
Abstract:
Provided is a light emitting diode (LED) driver. The LED driver includes a microcontroller for setting a level of an output current of the driver. The driver is configured to receive a prefix as an input, the prefix instructing the microcontroller to enter a programming mode. The microcontroller is responsive to a level signal representative of the level of the output current during the programming mode.
Abstract:
This disclosure describes embodiments of a lighting device with circuitry that can manage current and voltage levels across a plurality of fluorescent lamps. In one embodiment, the circuitry has cross-coupled inductors in series with a pair of lamp sockets. This configuration of components causes fluorescent lamps installed in the lamp sockets to generate substantially the same amount of light by drawing approximately equivalent current throughout the entire operable range of a dimmer control. The circuitry also includes a protection circuit with a winding magnetically coupled with the cross-coupled inductors and a control circuit that can cause impedance across the winding to change from a first impedance to a second impedance in response to operating conditions in the lamps. This feature avoids high operating voltages that can occur across the cross-coupled inductors when one of the fluorescent lamps is inoperable and/or removed from the lamp sockets.
Abstract:
Provided is a lighting system that includes a plurality of lighting elements which emit light, a power supply which supplies power, a lighting driver comprising a microcontroller and which outputs power to the plurality of lighting elements for operation thereof; and a control system which transmits a control signal to the microcontroller to initiate a standby mode of the plurality of lighting elements. The microcontroller receives the control signal and decreases output power supplied to the plurality of lighting elements, while remaining in a low power consumption mode for communicating with the control system during standby mode.
Abstract:
Provided is a lighting system that includes a plurality of lighting elements to emit light, a power supply to supply power, a lighting driver including a microcontroller and to output power to the plurality of lighting elements for operation thereof, a control system to transmit a control signal to the microcontroller to initiate a standby mode of the plurality of lighting elements, and a semiconductor device configured to receive voltage from the microcontroller, and selectively enable and disable a low power consumption mode of the lighting driver, to thereby maintain voltage for communication between the microcontroller and the control system during the standby mode.
Abstract:
A power factor controller (PFC) for an electrical load such as LED lighting includes a power factor correcting converter for generating a sinusoidal input current. The PFC further includes a programmable controller for estimating a phase shifted multiplier. A current regulator generates a desired PFC current in response to an input voltage, an output load and the phase shifted and subsequently blanked multiplier. The electrical load operates in response to the sinusoidal input current based at least partially on the desired PFC current.
Abstract:
A power factor controller (PFC) for an electrical load such as LED lighting includes a power factor correcting converter for generating a sinusoidal input current. The PFC further includes a programmable controller for estimating a phase shifted multiplier. A current regulator generates a desired PFC current in response to an input voltage, an output load and the phase shifted and subsequently blanked multiplier. The electrical load operates in response to the sinusoidal input current based at least partially on the desired PFC current.
Abstract:
Provided is a system for reducing power consumption in digitally addressable lighting interfaces (DALI), the system including a processor having at least one pin, a transistor coupled to the processor and a resistive network coupled to the processor and the resistive network.
Abstract:
A method for mitigating visual fluctuation of light output at low pulse width modulation levels is disclosed. The method comprises at least the step of comparing the percent change of a previously applied input voltage value to the pulse width modulation output.
Abstract:
A dimming control circuit for an LED module includes an LED driver configured to provide an output voltage that is used to drive the LED module, a voltage divider coupled to the output voltage, and a dimming control module coupled to the voltage divider. The dimming control module configured to change a resistance of the voltage divider to reduce the output voltage from the LED driver and dim the LED module.