Universal Lighting Technologies, Inc.

Scott Price

Wei Xiong

Stephen D Mays, Ii

John Jay Dernovsek

Dane Sutherland

Reggie Anglin

Candice Ungacta

Keith Davis

Danny Pugh

Matthew Gann

Rohan Dayal

Haiqing (Paul) Yang

Kevin Boyce

John J Dernovsek, Ii

A two-stage driver supplies current to an LED load. A first stage of the driver generates a bulk voltage. A second stage has a flyback transformer with a primary winding and a secondary winding. The second stage generates an output voltage to cause LED load current. The primary winding is turned on and off by a gating signal. Control logic within the second stage is responsive to initially turning on the driver to perform a startup short circuit test of the output circuit by applying a gating signal with a short on-time and a low switching frequency. If the output circuit is not shorted, the control logic increases the on-time and the switching frequency to detect if an output current is excessive. If the output current is not excessive, the control logic adjusts the on-time and the frequency to provide sufficient current to illuminate the LED load.

Startup current control method for flyback converter

A two-stage driver supplies current to a light emitting diode (LED) load. The driver includes a first stage and a second stage. The second stage is configured to generate a desired current through the LED load. The second stage has a flyback converter having a flyback transformer with a primary winding and a secondary winding. The primary winding is turned on and off by a gating signal. An induced voltage in the secondary winding rings when a current in the secondary winding is discharged. The flyback converter is configured to turn on the primary winding only during a detected valley in the ringing of the secondary winding. If the primary winding is turned on during a detected valley different from the previous detected valley, a valley jump is detected and the switching frequency is adjusted.

Dynamic valley sensing method for double flyback LED driver

Multi-driver configuration apparatuses, systems, and methods are provided. Apparatuses, systems, and methods are provided for multi-driver configuration of a plurality of light emitting diode (LED) drivers. The system includes a plurality of LED drivers having a transformer, an input interface coupleable to the configuration device via a common communication medium, a microcontroller, a direct current (DC) sensing section to detect at least a portion of a tuning signal received at the input interface and to transmit a driver control input signal corresponding to the at least a portion of the tuning signal to the microcontroller, and a transmit switch configured to receive a driver control output signal from the microcontroller and to cause at least one output signal to be output from the LED driver via the input interface. A configuration device transmits the tuning signal to at least one LED driver.

Method and circuitry to configure multiple drivers simultaneously

An LED driver includes a temperature sensing circuit integrated within its housing. The sensing circuit generates signals corresponding to actual temperature values within the driver housing to a controller. The controller receives programmable temperature derating parameters at least partially related to a light fixture receiving the driver housing, converts the temperature sensor signal into the actual temperature value, and derates the output current in linear fashion according to a transfer function when the actual temperature value falls within the temperature derating parameters. The parameters may include starting and ending temperatures, and an ending current parameter. The temperature sensing circuit may include a voltage divider with a negative thermal coefficient (NTC) device, preferably as the high side resistor. The temperature sensing circuit may typically provide a non-linear output across the temperature range, wherein the controller converts the non-linear output from the sensing circuit into a linear output for the transfer function.

LED driver with programmable internal NTC temperature foldback

A resonant power converter as disclosed herein, e.g., an LED driver, comprises first and second switches in a half-bridge arrangement and responsive at an operating frequency to controlled drive signals. A resonant circuit is coupled between the switch output and an isolation transformer. A negative feedback control loop provides an error signal for regulation of the output current. A reference control circuit is added to the feedback control loop, and configured to sense when the error signal exceeds a threshold value, and further configured in response to control a feedback reference signal wherein the error signal is reset to a value below the threshold value. By resetting the feedback control reference value, loop runaway may be prevented, e.g., for enough time that the LED load may warm up or otherwise stabilize. As a result the LED driver will always maintain negative current closed loop control, and restore normal operating mode.

Power control method during input line voltage fluctuation

A portable apparatus is provided for configuring and/or programming lighting drivers without mains power application. An apparatus housing comprises first and second connectors and an antenna. During a first mode wherein the first connector is coupled to an external computing device, a battery receives and stores power therefrom, and a first controller receives and stores at least driver configuration settings therefrom. When the external device is disconnected the battery powers the apparatus, which polls a transceiver circuit to detect a driver antenna proximate to the apparatus antenna. The apparatus housing is configured to mount to a luminaire comprising the detected driver, wherein the second connector is coupled to the driver and the battery provides power to a driver controller. The first controller also during this second mode transfers the stored at least driver configuration settings to the driver controller via the operably proximate antennae, for example via bidirectional negotiations therewith.

Device and method for programming or configuring of NFC equipped LED driver

A luminaire otherwise lacking connectivity is provided hereby with an isolated method for connecting to a lighting control system. The luminaire comprises an NFC-equipped LED driver having a first antenna. A digital control device with a second antenna is permanently or semi-permanently mounted in or on the luminaire wherein the second antenna is positioned in operable proximity with the first antenna. The digital control device includes a first transceiver in communication with the external device and a first controller to receive and store device configuration data from the external device in volatile memory associated with a second transceiver linked to the first antenna. A controller associated with the LED driver selectively obtains the device configuration data from the volatile memory via the NFC field, and generates output current reference signals for regulating the output current from the LED driver, said reference signals corresponding to the device configuration data.

Isolated digital control device for LED driver using NFC technology

A lighting device (e.g. LED driver) includes digital dimming, configuration and firmware updating via wireless communication circuitry and associated volatile memory (e.g., SRAM). A power stage converts AC mains input into a DC bus voltage, and further converts the DC bus voltage into output current for driving a load. A power distribution circuit generates a regulated DC voltage based on the DC bus voltage. A wireless interface circuit is linked to a wireless communications network (e.g., NFC), and configured to receive device configuration data during at least first operating conditions when the regulated DC voltage is unavailable, and further to receive dimming control data during second operating conditions when the regulated DC voltage is available. A controller generates gate driving signals for regulating the output current from the power stage, said gate driving signals generated based at least in part on the device configuration data and the dimming control data.

Electrically isolated system and method for digital regulation of a programmable lighting device

A lighting device, and method of controlling a power stage thereof, is provided to stabilize operation at low output currents. An output current is sensed as a feedback signal and provided to control circuitry, which further defines upper and lower boundaries for a control band about an average sensed input control value. A reference signal corresponds to the average sensed input control value, wherein adjustments to the reference signal are enabled only when an actual sensed input control value extends beyond the control band. The upper and lower boundaries may be linearly or non-linearly approaching the average control value as a function of increases in the average control value, to prevent control adjustments in particular for low output current conditions. Control signals are generated for driving one or more switching elements in the power stage, based at least in part on the feedback signal and the generated reference signal.

Lighting device with dimming reference control method to stabilize low output current

A lighting device is provided with input terminals that receive corresponding terminals from any one of an analog or digital dimming device or a driver configuration device. Depending on the type of connected device, different circuits are enabled by a controller to receive dimming control signals from an analog or digital dimming device, or to receive device configuration data from a multiple driver configuration device. A wireless interface circuit receives and stores configuration data via an antenna. The controller automatically detects whether one of the analog or digital dimming device or the driver configuration device is coupled to the input terminals, enables a corresponding one of the analog and digital interface circuit or the driver configuration interface circuit, and generates output current reference signals for regulating the output current from the driving circuit, said reference signals corresponding to the received dimming control signals via the analog and digital interface circuit.

Multiple interface LED driver with inherent overvoltage protection

A driver circuit provides power from a power source to a load. The driver circuit includes a surge protector, an input stage (e.g., full wave rectifier), a controller, an overvoltage protection circuit, and an output stage (e.g., a half bridge inverter). The input stage receives power from the power source and provides a direct current (DC) power rail. The controller operates the output stage to provide power from the DC power rail to the load. The overvoltage protection circuit shuts down the controller when the DC power rail exceeds a predetermined voltage. This ceases operation of the output stage, protecting the output stage from damage while the DC power rail is above the predetermined voltage.

Surge protection circuit for a half-bridge power converter

A system for a linear isolated power supply circuit may include a boost converter having a boost inductor winding and an auxiliary side winding, the auxiliary side winding configured to be magnetically coupled to the boost inductor winding. The linear isolated power supply circuit includes a voltage sensing circuit coupled to the auxiliary side winding, the voltage sensing circuit configured to measure an input voltage at an isolated circuit associated with the auxiliary winding. The linear isolated power supply circuit includes a processor configured to receive the measured input voltage from the voltage sensing circuit and to cause at least one operation to be performed by the processor based at least in part upon the measured input voltage. Methods and apparatuses corresponding to the system are provided.

Input voltage sense circuit for boost power factor correction in isolated power supplies

A protection system for an LED driver includes a voltage rail, an input voltage source, and a surge protector connected between the input voltage source and the voltage rail. The voltage change sensing block detects a change in a voltage associated with the input voltage source. The protection system further includes a voltage sensing block connected to the voltage change sensor. A half-bridge switching circuit may include a switch controller, a first switching element, and a second switching element. The switch controller controls an operating state of each of the first switching element and the second switching element. A reset block disables at least one of the switch controller, the first sensing element, and the second switching element, responsive to a control signal associated with at least one of the voltage change sensing block and the voltage sensing block.

Surge protection system and method for an LED driver

An LED driver circuit capable of being tuned via an unpowered tuning process and associated methods are provided. A radio frequency (RF) coupling circuit receives an RF tuning signal having a plurality of cycles of an RF carrier. The RF coupling circuit outputs a coupled RF tuning signal to a direct current (DC) generator circuit which rectifies the coupled RF tuning signal and outputs a rectified RF tuning voltage. A RF demodulation circuit receives the rectified RF tuning signal and selectively converts each burst of the rectified RF tuning signal to a single DC pulse. The RF demodulation circuit includes a Zener diode limiting the emitted voltage from the RF demodulation circuit. The microcontroller receives the output of the RF demodulation circuit, receives the regulated voltage, and controls one or more tuning operations of the LED driver circuit.

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Madison, AL, United States of America

Scott Price