Abstract: An LED driver is configured to minimize power consumption during standby operating modes. The LED driver includes power factor correction (PFC) and isolated DC-DC conversion stages, driven by respective first and second regulators. An auxiliary sensor detects environmental conditions for a controller which generates standby or normal operating mode signals based thereon. A low standby isolated power supply circuit receives operating mode signals and is configured: responsive to normal operating mode signals to enable the voltage regulators; responsive to standby mode signals to disable the voltage regulators, and in both modes to supply power to the controller and auxiliary sensor. Accordingly, the controller and auxiliary sensor are continuously enabled whereas the PFC and DC-DC stages of the LED driver are disabled during standby modes. Additional circuitry may selectively disconnect voltage sensing resistance networks from the LED driver for further reductions in power consumption during standby mode.

Abstract: An apparatus and a method reduce the ripple on a load current through an LED load. The load current is provided by a flyback converter, which is responsive to a feedback signal to maintain the output current at or near a selected magnitude. The LED load has an AC resistance which is at least one cause of the ripple on the load current. A stabilizing resistor in the current path to the LED load reduces the magnitude of the ripple caused by the AC resistance. The stabilizing resistor may have a constant stabilizing resistance value for different LED loads; or the stabilizing resistor have a dynamic stabilizing resistance value such that the stabilizing resistance value is greater when the LED load has fewer LEDs and is smaller when the LED load has more LEDs.

Abstract: 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.

Abstract: A driver circuit includes a combined current and voltage control circuit for driving a light emitting diode (LED) load. The driver circuit includes an isolation transformer having primary, secondary, and auxiliary windings. A primary side circuit is coupled to the primary winding and includes a power factor controller and a switch. The power factor controller controls an output current to the LED load by controlling an operational state of the switch. A secondary side circuit is coupled to the secondary winding. The secondary side circuit includes a proportional and integration (PI) control portion which outputs a control signal. A combined voltage and current control circuit is coupled to the auxiliary winding and includes an optocoupler coupled to the power factor controller and to the PI control section. The combined voltage and current control circuit transmits a control signal from the PI control section to the power factor controller.

Abstract: A driver circuit of a light fixture includes a half-bridge inverter, a resonant tank circuit, an isolating transformer, an output rectifier, and a controller. The half-bridge inverter provides an alternating current signal to the resonant tank circuit. The resonant tank circuit includes a resonant inductor, a resonant capacitor, a first clamping diode, and a second clamping diode. The clamping diodes limit the voltage of the resonant capacitor to a power rail voltage and a ground voltage. The isolating transformer is connected to the resonant tank circuit. The controller senses current provided to the light source and adjusts a switching frequency of the half-bridge inverter to maintain the sensed current at a target current. The driver circuit operates as a constant current source with a self-limited output voltage determined as a function of the voltage of the power rail and the turns ration of the isolating transformer.

Abstract: A bobbin provides secure attachment of a magnetic component to a printed circuit board. The circuit board includes a set of slotted apertures and a set of tubular apertures. The bobbin includes at least two pin rails and a plurality of standoffs proximate each pin rail. L-shaped pins are attached to one of the pin rails. Straight pins are attached to the other pin rail. The component further includes a core, and at least one winding. The L-shaped pins are shaped to pass through and slide within the set of slotted apertures. The L-shaped pins engage the bottom surface of the circuit board when the straight pins are inserted through the set of tubular apertures (i.e., in a secured position). In the secured position, the magnetic component is held in place against the top surface of the circuit board and provides a soldering area for mounting on the bottom surface.

Abstract: A lighting control system may include a main lighting controller having an opening therein and a main coupler for connecting to an expansion pack. An expansion pack of the lighting control system may have a connector having an opening therein and an expansion coupler for connecting to the main lighting controller. Junction boxes may be configured to connect to the main lighting controller and expansion pack based on a predetermined distance associated with openings of the main lighting controller and expansion pack. Installation of a combined main lighting controller and expansion pack at a plurality of junction boxes may be coordinated. A method may include combining a main lighting controller and an expansion pack, connecting two or more junction boxes to one another to form an array, and connecting the two or more junction boxes to the main lighting controller and expansion pack in accordance with a predetermined spacing.

Abstract: 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.

Abstract: An AC LED driver for providing operating power to an LED load. The AC LED driver includes a first input terminal and a second input terminal, each of the first and second input terminals connectable to an AC input voltage source. The AC LED driver further includes a current limiting capacitor coupled to the first input terminal and a bridge rectifier coupled to the current limiting capacitor, the bridge rectifier having a plurality of rectifying diodes. The AC LED driver also includes a phase angle shift unit coupled to the first input terminal and the bridge rectifier, the phase angle shift unit configured to minimize a phase angle between input line current and input voltage received via at least one of the first input terminal and the second input terminal.

Abstract: A magnetic device for an electronic circuit includes a printed circuit board. A first and second magnetic component assembly can be electrically connected to the printed circuit. The second magnetic component assembly can be stacked on the first magnetic component assembly. The first magnetic component assembly can be positioned between the second magnetic component assembly and the printed circuit board. Each magnetic component assembly can include a bobbin, a winding disposed on the bobbin, and a core extending through the bobbin. A second bobbin on the second magnetic component can be positioned on either a first core or a first bobbin of the first magnetic component assembly. The stacked magnetic component configuration can help reduce the board space required to electrically connect both the first and second magnetic component assemblies to the printed circuit board, which can help increase the power density of the magnetic device.

Abstract: A magnetic assembly includes a single bobbin structure that supports a first coil and a second coil. A first E-core has a center leg positioned within the first coil. A second E-core has a center leg positioned within the second coil. An I-core is positioned between the first E-core and the second E-core. The I-core completes a first set of magnetic paths between the center leg and outer legs of the first E-core and also completes a second set of magnetic paths between the center leg and outer legs of the second E-core. The two E-cores and the I-core are stacked in a vertical E-I-E configuration with respect to a common set of pin rails. In one embodiment, the first coil and the first E-core are configured as a transformer; and the second coil and the second E-core are configured as an inductor.

Abstract: An adjustable auxiliary power supply for a light emitting diode (LED) driver for adjusting an auxiliary power output includes a voltage regulator configured to receive a regulator input voltage and to output an auxiliary power supply voltage selected from a first output voltage and a second output voltage according to a voltage selection signal used to control an LED lighting setting. The adjustable auxiliary power supply includes a first and second input voltage circuits configured to selectively output respective first and second input voltages to the voltage regulator. The adjustable auxiliary power supply includes an adjustable resistance circuit coupled to the voltage regulator. The adjustable resistance circuit controls the auxiliary power supply voltage based upon an adjustable resistance setting of the adjustable resistance circuit. The adjustable resistance setting is configured to correspond to at least one of the first output voltage and the second output voltage.

Abstract: A portable indirect lighting apparatus includes first and second support structures. Each support structure includes a respective longitudinal light source having a linear array of light-emitting diodes (LEDs). A respective longitudinal lens is positioned proximate to each linear array of LEDs to receive and redirect the light emitted by the LEDs. A flexible reflector extends between the first and second support structure. The reflector has at least one diffusedly reflective surface. The reflector is configurable to an operational configuration with the diffusedly reflective surface positioned to receive the light redirected by the first and second longitudinal lenses. The reflector is configurable to a transportable configuration with at least a portion of the reflector wrapped around at least one of the first and second support structures.

Abstract: An LED driver is provided with transient protection circuitry to satisfy dielectric testing requirements. An embodiment of the driver includes a fuse coupled between an AC input and a DC power source, and first and second electrolytic capacitors coupled across the DC power source. Respective circuits including a transient voltage suppressor and a current limiting resistor are coupled in series across each of the electrolytic capacitors. The transient voltage suppressors have breakdown voltage thresholds slightly below a full rated output for the DC source, wherein a sensed short condition across one of the first and second electrolytic capacitors causes a short circuit across the DC source and thereby disabling of the LED driver prior to failure of the other electrolytic capacitor. The current limiting resistors further are configured to avoid causing the LED driver to be disabled for transient overvoltage conditions in which neither of the electrolytic capacitors is shorted.

Abstract: A magnetic assembly includes a bobbin with two end flanges. A passageway extends longitudinally between the end flanges. An inner core extends through, and is centered in, the passageway. The inner core has first and second end surfaces, each surface proximate to one of the end flanges. A rectangular outer core is positioned around the bobbin with inner surfaces of the outer core close to the outer surfaces of the end flanges of the bobbin. A respective gap is formed between each end of the inner core and the adjacent inner surface of the outer core. The passageway includes crushable ribs that secure the inner core within the passageway. The outer surfaces of the end flanges include crushable ribs that secure the core with respect to the bobbin. The passageway and inner core may have an oval-shaped profile. The passageway and inner core may have a circular profile.

Abstract: A power over Ethernet (PoE) interface device includes a knockout adapter. The knockout adapter is configured for mounting to a conduit knockout opening in an LED luminaire. The interface device includes a power assembly having an input section and an output section. The power assembly is connected to the knockout adapter such that the output section is positioned inside the luminaire when the knockout adapter is mounted to the luminaire. The power assembly further includes a data connector mounted to the input section. The data connector is configured to receive PoE signals from a data cable coupled to the data connector. Power output terminals are mounted to the output section and electrically coupled to the data connector. The power output terminals may be configured to couple the PoE signals from the data connector to an LED light source in the luminaire.

Abstract: A DC-to-AC inverter provides power to a DC-to-AC converter via an isolation transformer. The DC-to-AC converter drives a DC load. A sensing circuit on the primary side of the isolation transformer senses the current flowing through the primary winding of the transformer. A capacitor is connected across the primary winding in parallel with the magnetizing inductance of the primary winding to form a parallel L-C combination. The capacitance of the capacitor is selected with respect to the magnetizing inductance such that the parallel L-C combination resonates at a nominal steady-state operating frequency of the DC-to-AC inverter, which causes the current through the primary winding to be proportional to a current through the DC load. The current through the primary winding is sensed and provided as a feedback signal to the DC-to-AC inverter to cause the DC-to-AC inverter to adjust the operating frequency to maintain the current at a desired magnitude.

Abstract: A magnetic device for an electronic circuit includes a printed circuit board. A first and second magnetic component assembly can be electrically connected to the printed circuit. The second magnetic component assembly can be stacked on the first magnetic component assembly. The first magnetic component assembly can be positioned between the second magnetic component assembly and the printed circuit board. Each magnetic component assembly can include a bobbin, a winding disposed on the bobbin, and a core extending through the bobbin. A second bobbin on the second magnetic component can be positioned on either a first core or a first bobbin of the first magnetic component assembly. The stacked magnetic component configuration can help reduce the board space required to electrically connect both the first and second magnetic component assemblies to the printed circuit board, which can help increase the power density of the magnetic device.

Abstract: An LED driver circuit and a method prevent LED turn-off flash when input power is lost to the driver circuit. The driver circuit includes a DC-DC converter that provides an LED drive voltage to an LED load. A voltage drop sensing circuit detects the loss of input power and discharges a filter capacitor that provides operating power to a controller in a DC-DC converter. The controller turns off to halt the operation of the DC-DC converter before the voltage provided to the LED load decreases to a turn-off threshold of the LED load. The DC-DC converter cannot recharge a load capacitor across the LED load. Thus, once the LEDs in the LED load turn off, the LEDs remain off until the input power is restored.

Abstract: An LED driver tuning system includes an LED driver configured to receive a tuning interface device at line and neutral mains inputs. During online operation, a power converter generates output power to LED arrays based on dimming control signals and programmed operating parameters. The tuning interface device provides predetermined sequences of digital pulses to a controller during offline mode of operation, wherein the controller modifies programmed operating parameters upon decoding the predetermined sequence of digital pulses and determining a corresponding target value for the parameter(s). Upon reinitiating online operation, the output power generated by the power converter is regulated based on the dimming control signal, a sensed output from the power converter, and the modified programmed operating parameters. A tuning confirmation circuit is configured to generate an inverse of the predetermined sequence of digital pulses so the tuning device can confirm proper receipt of the signals.