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 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 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 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: 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 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 provides constant output power with wide range output current and voltage. A parallel resonant tank configuration is supplemented by resonant gain clamping circuit configured to partially cancel voltage across the resonant capacitor during half-bridge switching operation. Voltage between the resonant components is clamped to one-half a driver input voltage, ensuring inductive switching of the half-bridge. An output transformer has a primary winding coupled across the resonant capacitor, with a center tap defining first and second portions. An output voltage clamping circuit is coupled across the DC input power source and to the center tap, wherein maximum voltage across the primary is clamped based on a relationship between respective numbers of turns in the first and second portions, and maximum voltage across a secondary winding is clamped based on a relationship between the respective numbers of turns in the secondary winding and the first and second portions.

Abstract: An adapter is provided for retrofitting a lighting fixture with a light emitting diode (LED) lamp. The adapter includes a pin plate and a retaining ring. The pin plate includes at least one pin extending outward from a distal side of the pin plate. The retaining ring includes a base, at least one arm, and at least one projecting member, each having inward and outward surfaces. The at least one pin restricts movement of the adapter when the adapter is rotated to a restraining position. The at least one projecting member causes the inward surface of the at least one projecting member to face the inward surface of the base. The at least one projecting member restricts movement of the adapter in a direction corresponding to an axis of rotation of the adapter using the at least one projecting member.

Abstract: A magnetic component for an electronic circuit includes a core having one or more core surface grooves defined on a side wall, an end wall or both, along the outer core perimeter. Each core surface groove can improve heat flux away from the magnetic component. In some embodiments, a thermally conductive gap filler material is disposed adjacent one or more of the core surface grooves. An electronic device includes a magnetic component with one or more core surface grooves positioned on a circuit board inside an enclosure. The gap filler material spans a gap between the magnetic component and an enclosure wall interior surface, thereby providing a thermal bridge between the component and the enclosure facilitating heat flux away from the core to the enclosure wall.

Abstract: A ballast configured for multiple parallel lamp operation includes a system for detecting unbalanced loads or absent lamps in a parallel multiple lamp ballast. The ballast includes one or more starting transformers having windings, each winding connected in series with a lamp connected to the ballast. A winding of one or more of the starting transformers that is not connected in series with one of the lamps is monitored for a voltage in excess of a threshold. A voltage in excess of the threshold across the winding is indicative of an unbalanced load (e.g., an absent or broken lamp). If a voltage above the threshold is detected across the monitored load, the ballast ceases powering the lamps.

Abstract: An edge-lit lighting apparatus includes a light source and a light guide body. The light guide body includes an input edge, the light source positioned to project light through the input edge in a primary emission direction, the light guide extending from the input edge. The light guide body includes a mean elongation plane which is angularly offset from the primary emission direction. The light guide body includes a reflective side adjacent the input edge and configured to redirect light from the light source. The light guide includes an output side configured to disperse redirected light from the reflected side. The light guide body can extend curvilinearly from the input edge. The lighting apparatus can be configured as an indirect lighting system, and can help increase efficiency for edge-lit lighting systems.

Abstract: A light emitting apparatus includes a substrate, a light emitter mounted on the substrate, and a lens at least partially covering the light emitter, the lens defining a space about the light emitter. A heat sink is attached to the substrate. The heat sink is configured to dissipate heat from the light emitter via the substrate. The substrate includes an opening communicated with the space. A vent passage is at least partially defined between the heat sink and the substrate, the vent passage communicating the opening in the substrate with an exterior of the heat sink.

Abstract: A power factor correction (PFC) circuit includes an adaptive multiplier feedback control circuit to enhance stability of the PFC circuit for high input voltage and low input power (i.e., low input current) conditions. The adaptive multiplier feedback control circuit controls a voltage provided to a multiplier voltage input of a controller of the PFC circuit. The controller determines control loop gain as a function of the voltage at the multiplier voltage input terminal of the controller. The adaptive multiplier feedback control circuit increases the voltage at the multiplier voltage input of the controller is the input current to the PFC circuit increases. The PFC circuit may be used in an AC to DC converter of the driver circuit of a light fixture operable to provide power to a light source of the light fixture.

Abstract: A lighting apparatus includes a light source. A primary optical surface is configured to receive and redirect light from the light source. A secondary optical surface is configured to receive redirected light from the primary optical surface and further redirect the light in a primary emission direction. The apparatus includes a central opening through the apparatus, the central opening defining a convective path through the apparatus. A thermally conductive cover is placed over the central opening and is positioned in the convective path. The primary optical surface is positioned such that a direct view of the light source is obstructed when the apparatus is viewed from the primary emission direction. The primary and secondary optical surfaces are substantially symmetric about the central opening.

Abstract: A high power factor DC power supply with low output ripple uses a variable gain DC to DC converter and fast averaging control loop to eliminate the need for a large electrolytic capacitor at the output of the PFC circuit. A resonant tank circuit of the DC to DC converter is sized to provide a predetermined output voltage to the load when the PFC circuit output is at its minimum. A closed loop control circuit varies an operational frequency of the DC to DC converter (i.e., an inverter of the DC to DC converter driving the resonant tank circuit) to compensate for voltage ripple on the DC power rail provided to the DC to DC converter from the PFC circuit. An optional clamping circuit limits output from the resonant tank to the load to further reduce ripple in the power provided to the load.

Abstract: A power line communication system communicates dimming levels to a lighting circuit over AC power lines. A power line controller generates control signals which are inserted on the AC power signal to the lighting circuit. A first series resonant circuit is coupled across the AC lines to bypass high frequency components from the control signals. A power line receiver receives the AC power signal and extracts the control signal to generate dimming level signals corresponding with the desired dimming level. To extract the control signal out of the AC power signal, the power line receiver has a resonant circuit connected in parallel with the AC power line and tuned to transmit the ballast control signal and to filter out the AC power signal. A dimming level sensing circuit then senses the signal pattern on the control signal and generates a dimming level signal corresponding to the desired dimming level.

Abstract: A bobbin apparatus for a magnetic component includes a core passage having one or more core passage steps located therein. The core passage steps provide one or more gaps between a core disposed in the core passage and the bobbin body. A potting material may be disposed in the gap or gaps in some applications to enhance heat transfer and/or to improve magnetic component performance by reducing effects of fringing flux on inner windings. A method of assembling a magnetic component to include one or more gaps between the core and bobbin core passage is also provided.

Abstract: An auxiliary winding circuit board includes one or more auxiliary conductive windings. The auxiliary winding circuit board is positioned at an axial end of a bobbin, and a core leg extends through an opening in the auxiliary winding circuit board. A main conductive winding is positioned on the bobbin. The auxiliary winding disposed on the auxiliary printed circuit board has enhanced voltage-isolation from the main winding positioned on the bobbin, allowing both a high-voltage main winding and a low-voltage auxiliary winding to be located on one magnetic component. The magnetic component is configured for mounting on a printed circuit board for an electronic device such as a power supply. A modular magnetic component apparatus includes a bobbin with main winding assembly and multiple auxiliary winding circuit boards that may be interchangeably mounted between the bobbin and core for desired applications.