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 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: A magnetic device for an electronic circuit includes a bobbin having a bobbin body with an axial passage, a first pin rail, and a second pin rail. A winding can be disposed around the bobbin body. A core can have a core leg extending into the axial passage. The bobbin can be disposed on a printed circuit board. The core and the winding can be elevated off of the printed circuit board. The bobbin can include a first spacing member positioned between the bobbin body and the first pin rail, and a second spacing member positioned between the bobbin body and the second pin rail. The core can be positioned on the first and second spacing members such that the core is at an offset position from the first and second bobbin pin rails. The winding can additionally be offset from the first and second pin rails.

Abstract: An LED driver apparatus provides discrete output current configuration. User interfaces such as dip switches enable user selection of output current settings. LED driver circuitry includes an inverter, a primary transformer winding coupled to the inverter switches and providing resonant inductance, and a secondary transformer winding coupled on a first end to an output rectifier. Various circuit branches are coupled in parallel between the output rectifier and the secondary winding, each including a switching element driven between open and closed states associated with the user-selected output current setting. The circuit branches may be coupled to respective secondary winding taps, wherein output current is regulated according to an effective turns ratio defined by the closed circuit branch.

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 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 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: 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.

Abstract: An area lighting control system is provided for a light fixture and occupancy sensors. In a pairing mode, the occupancy sensors transmit messages with respective unique addresses to the light fixture, which identifies an associated sensor network. Upon lapsing of the pairing mode, an operating mode follows during which the sensors transmit output signals representative of occupancy in the area, and the light fixture regulates respective light sources based on an occupancy state determined according to output signals received from the associated network. The output signals are transmitted according to pseudo-random time intervals in order to reduce wireless transmission collisions, and only upon determining no occupancy in the defined area. When signals are received from all sensors in the network during a predetermined time period, the light fixture dims the light sources, whereas otherwise the light fixture operates the light sources at full lighting state.

Abstract: A lighting apparatus includes a light source located on a centerline, a light redirecting lens positioned to receive light from the light source, and an outer reflector that receives light redirected by the redirecting lens. The redirecting lens includes an inner reflecting portion that includes a total internal reflection (TIR) surface that reflects light outward to an outer refracting portion. The outer refracting portion of the redirecting lens refracts the light outward and away from the position of the light source. The outer reflector receives the refracted light and reflects the inward toward the centerline and farther away from the light source. The lighting apparatus further includes a diffuser that diffuses the light from the outer reflector. The lighting apparatus may be configured longitudinally or may be configured to be rotationally symmetrical with respect to the centerline.

Abstract: An LED driver circuit is provided with a dynamic operating range which can be set using an offline tuning interface. During an offline mode of operation, the tuning interface may be coupled to the dimming control interface and provide both power and one or more digital pulses corresponding to a desired maximum output voltage and/or maximum output current. The controller then modifies the programmed maximum output voltage and the maximum output current values based on the one or more digital pulses received via the tuning interface circuit. Group tuning is permitted by way of a shared bus between a programming device and a plurality of LED driver circuits. Tuning confirmation or error may be detected by an LED driver circuit and the programming device may be notified of the success or failure of a particular tuning operation.

Abstract: A lighting control system is provided with a communication method utilizing downstream current modulation. A primary controller is electrically coupled to a plurality of lighting devices via a mains power transmission network. Each of the respective lighting devices includes an occupancy sensor and is configured to provide full illumination when occupancy is detected in the associated area. The controller identifies occupancy by an increase in current on the mains lines, directs the other devices to fully illuminate, and activates a timer. Prior to lapsing of the timer, any of the devices may indicate continued occupancy by adjusting an operating current to a respective light source according to a predetermined pattern. Upon identifying the pattern, the controller generates control signals directing each of the other devices to remain fully illuminated, and resets the timer. The predetermined pattern may for example include amplitude modulation, threshold numbers of cycles, or both.

Abstract: A magnetic component includes a first core half having a core body with first and second core legs protruding from the core body and a middle core leg protruding from the core body between the first and second core legs. A first U-shaped channel is defined between the first core leg and the middle core leg, and a second U-shaped channel is defined between the second core leg and the middle core leg. A first rounded outer core surface is disposed on the core body oriented substantially parallel to the first U-shaped channel, and a second rounded outer core surface is disposed on the core body oriented substantially parallel to the second U-shaped channel. In some embodiments, a second core half having a similar shape is positioned oppositely adjacent the first core, and a bobbin structure is positioned on the middle core legs such that the first and second U-shaped channels form transverse clearance openings in the magnetic component.

Abstract: A lens for distributing light from a light emitter in a desired asymmetric illumination profile includes a lens body having an input side and an output side. The input side receives light from an emitter, and the output side includes primary refractive surface, total internal reflection surfaces, and a secondary refractive surface associated with the total internal refection surfaces. A primary emission axis associated with the emitter is defined through the lens body, and a transverse reference plane is positioned parallel to the primary emission axis. A desired illumination region is located on a first side of the reference plane, and a desired dark region is located on a second side of the reference plane. The primary refractive surface, the total internal reflection surfaces and the secondary refractive surface direct a substantial portion of the light from the emitter to the desired illumination region.

Abstract: An LED driver circuit is provided with a dynamic operating range which can be set using an offline tuning interface. During an online mode of operation, a controller for a power converter is configured to regulate the output voltage and the output current generated by the power converter based on a dimming control signal from a dimming control interface, a sensed output from the power converter, and programmed maximum output voltage and maximum output current values. During an offline mode of operation, the tuning interface may be coupled to the dimming control interface and provides a sequence of digital pulses corresponding to a desired maximum output voltage, maximum output current, or operating parameter. The controller then modifies the programmed maximum output voltage and the maximum output current values based on the predetermined sequence of digital pulses received via the tuning interface circuit.

Abstract: A multi-channel LED driver is provided with a negative current sensing method for inherent output short circuit protection, as well as protection from output misconnection. A plurality of power converters are configured to drive respective LED arrays, each power converter respectively comprising a first stage configured to provide current through a primary winding of an isolation transformer. A second stage has a capacitor coupled in parallel with a secondary winding of the isolation transformer, a current sensing resistor coupled between the secondary winding and a circuit ground for the second stage. A filtering circuit is coupled on a first end to a node between the secondary winding and the current sensing resistor, and on a second end to the circuit ground. A feedback circuit is coupled between the first stage and the filtering circuit, and configured to deliver a control signal corresponding to current through the secondary winding.

Abstract: A low-profile lighting system includes an asymmetric area lens having a “batwing” configuration that receives light from at least one light-emitting diode (LED) that emits light having a Lambertian light distribution pattern. The asymmetric lens refracts the light to generate a modified light distribution pattern having light distributed in a selected range of angles. A first portion of the output surface of the asymmetric lens refracts light angularly away from a reference plane. A second portion of the output surface of the symmetric lens refracts light angularly toward the reference plane. The refracted light from the asymmetric lens is provided to a dispersion lens. The dispersion lens produces a dispersed light distribution pattern that illuminates an illumination area. In certain embodiments, the lens has a profile formed by an outer curve having the general shape of an Archimedean spiral or an involute curve.

Abstract: A control system for a light emitting diode (LED) driver is provided. The control system includes a control module, a command interface, and a combined signal interface. The control module includes a microcontroller configured to receive at least one signal and to determine an LED driver command signal and a command module connected to the microcontroller and capable of communicating with both the lighting dimmer and the wireless control module. The control system includes a command interface which communicatively couples the control module to the LED driver. A combined signal interface communicatively couples the command module and at least one of the lighting dimmer and the wireless control module. The combined signal interface conveys one or more signals between the control module and at least one of the lighting dimmer and the wireless control module. Associated methods and modules are also provided.