Universal Lighting Technologies, Inc.

Universal Douglas Lighting America

Dane Sutherland

Wei Xiong

Scott Price

Stephen D Mays, Ii

Donald Folker

John Jay Dernovsek

Mike LeBlanc

Matthew Gann

Keith Davis

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

An edge mount magnetic component includes a bobbin and two E-core halves. The bobbin is configured to receive the two E-core halves when body portions of the two E-core halves are positioned vertically. The bobbin includes a first outer flange, a second outer flange, and a passageway spanning therebetween. The bobbin further includes first, second, third, and fourth pin supports. The first and second pin supports are connected to an outer surface of the first end flange and are spaced apart by at least a width of the passageway. The third and fourth pin supports are connected to an outer surface of the second end flange and are spaced apart by at least the width of the passageway. The bobbin further includes slots for routing a winding to a pin and includes walls to ensure the winding is electrically separated from the E-core halves.

Bobbin for edge-mounted magnetic core

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

A power converter and method for improving the current control stability of power converter by balancing the secondary winding currents is provided herein. The power converter includes a primary circuit having switches controllably driven at an operating frequency to produce an AC output through a primary transformer winding, and a secondary circuit having first and second secondary windings having respective leakage inductances. The secondary circuit provides power at an output node based on a power transfer between the primary winding and the first and second secondary windings. At least one balance inductor is coupled in series with the first and second secondary windings, and configured to reduce a difference between the first leakage inductance and the second leakage inductance. The at least one balance inductor may further be configured to reduce a difference between first and second AC current peaks associated with the first and second secondary windings, respectively.

Method to balance the secondary winding current to improve the current control stability

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

A zero current detector control circuit controls a voltage applied to a zero current detector (ZCD) input of a power factor corrector integrated circuit (PFC IC) that produces a driver output having an on time and an off time. The zero current detector control circuit includes a voltage detection input circuit coupled to a rectified AC input voltage. The detector control circuit generates a control voltage applied to a control terminal of an electronic switch. When the rectified AC input voltage has a phase angle in a first portion or in a last portion of a half-cycle, the electronic switch conducts to connect a capacitor to the ZCD input of the PFC IC. The capacitor causes the fall time of the trailing edge of a pulse applied to the ZCD input to increase, which causes the off time of the driver output of the PFC IC to increase.

Adaptive off time control to improve total harmonic distortion and power factor for critical mode flyback type PFC circuits

A combination of a common-mode choke and two integrated RF inductors includes first and second E-core. At least one E-core includes first and second protrusions extending from a body portion. Each protrusion is configured to accommodate a respective winding. In a first embodiment, each protrusion extends from the body portion at an angle perpendicular to legs extending from the body portion. In a second embodiment, each protrusion extends from the body portion in an opposite direction from the legs extending from the body portion, and each protrusion includes a respective channel to receive a respective winding. In a third embodiment, each protrusion extends from the body portion in an opposite direction from the legs extending from the body portion, and each protrusion is sized and shaped to extend into a respective opening in a printed circuit board. Each opening is surrounded by a respective printed circuit winding.

Common-mode choke with integrated RF inductor winding

A voltage feedback circuit for a power factor correction circuit couples an output voltage to a voltage feedback input terminal of the power factor correction circuit. The voltage feedback circuit includes a first voltage sensing resistor, a second voltage sensing resistor and a third voltage sensing resistor. A stabilization capacitor is connected across the third voltage sensing resistor. During a normal mode of operation, a feedback voltage has a magnitude determined by the first, second and third voltage sensing resistors. When the output voltage increases rapidly, the stabilization capacitor bypasses the increased voltage around the third voltage sensing resistor to cause the magnitude of the feedback voltage to be determined by only the first and second voltage sensing resistors. The power factor correction circuit detects a transient overvoltage condition at a lower output voltage than if the third voltage sensing resistor were not bypassed.

Low loss voltage feedback method for power factor correction circuits

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 lighting system includes various ballasts or LED drivers having respective dimming interface circuits coupled in parallel to an external dimming device. Each device includes a controller regulating output to a lighting load based on desired dimming output. Dimming interface circuits coupled are between the controller and the external dimming device, each configured to dynamically adapt a level of constant current sourced from the dimming interface circuit to the external dimming device via first and second interface terminals, based on a determined analog mode or digital mode associated with the external device. The dimming interface circuit generates dimming control signals to the controller based on dimming input signals received via the first and second interface terminals, and in a digital mode, the interface circuit generates digital pulse signals to the external dimming device via the interface terminals for bidirectional communications therewith.

Lighting system and method for dynamically regulating driven current to an analog or digital dimming interface

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.

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Madison, AL, United States of America

Dane Sutherland