Abstract: An LED utility light has a one or more LED devices supported by a mounting structure and electrically connected to a mounting base section and to a boss and base cap for electrical engagement with a receptacle. LED device circuitry and conductive leads are located in the mounting structure and the mounting base section. A housing substantially surrounds the mounting structure.

Abstract: A luminous device for a vehicle includes a plurality of light-emitting diodes, a series resistor connecting the plurality of light-emitting diodes to a voltage source, and a control unit configured to control the light-emitting diodes by means of pulse widths modulation (PWM).

Abstract: The invention relates to a power supply system and a method for providing a load (L) with electrical power from either a first or a second AC grid source (10L, 10H) that supply different first and second AC voltages, respectively. In a particular example, said grid sources may belong to the US and the European mains, respectively, and the load may be a lamp with mains compatible LEDs (Ch1-Ch4). The power supply system comprises a first and a second connector device (30L, 30H) for connecting a converter circuit (20) to the first or the second AC grid source (10L, 10H), respectively. Moreover, the second connector device (30H) comprises a transformation circuit (D1-D4) for transforming the second AC voltage such that it yields a similar output voltage of the converter circuit (20) as the first AC voltage.

Abstract: A driving circuit of a light emitting diode (LED) including an AC power, a rectifier, a power converter, a waveform sampler, and a control circuit is provided. The AC power provides an AC signal. The rectifier is coupled to the AC power and outputs a driving signal. The power converter is coupled to the rectifier. The power converter includes an LED and outputs a first signal positive correlated with a current passing through the LED. The waveform sampler is coupled between the AC power and the rectifier, and outputs a second signal directly proportional to the AC signal. The control circuit is coupled between the waveform sampler and the power converter, and outputs a control signal to the power converter according to a comparison result between the first signal and the second signal.

Abstract: In response to turning-on of a lock-type power switch, an initial controller outputs a first voltage for a first period and a gate is turned on for the period via a first driver responsive to the first voltage, then DC power is supplied to a main circuit. During the period, a control processor causes a voltage output section to start outputting a second voltage so that the gate is turned on via a second driver to continue the DC power supply. When no event has been generated for a second period, the second voltage from the voltage output section is stopped to turn off the gate, thus the power supply to the main circuit is shut off. Once a power from outside is switched from OFF to ON while the power switch kept ON, the power supply to the main circuit is resumed via the controller and first driver.

Abstract: A light emitting diode lamp includes: two first pins which are provided at one side thereof; two second pins which are provided at the other side thereof; a light emitting diode (LED) module which is disposed between the two first pins and the two second pins; a circuit connecting at least two of the two first pins and the two second pins to the LED module; and a protection circuit including a fuse which is disposed at a front end of the LED module to protect the LED module in case of generation of high voltage. The circuit is configured to have a direction from a front end of the LED module to the other end thereof as a forward direction.

Abstract: In at least one embodiment, the controller senses a leading edge, phase cut AC input voltage value to a switching power converter during a cycle of the AC input voltage. The controller senses the voltage value at a time prior to a zero crossing of the AC input voltage and utilizes the voltage value to determine the approximate zero crossing. In at least one embodiment, by determining an approximate zero crossing of the AC input voltage, the controller is unaffected by any disturbances of the dimmer that could otherwise make detecting the zero crossing problematic. In at least one embodiment, the controller approximates the AC input voltage using a function that estimates a waveform of the AC input voltage and determines the approximate zero crossing of the AC input voltage from the approximation of the AC input voltage.

Abstract: Dimming ballasts and methods are presented for powering a plurality of fluorescent lamps in which at most one of the lamps is selectively dimmed while all the remaining lamps are turned on or off according to a dimming level setpoint to allow dimming to match a user's desired lighting level while maintaining high efficiency.

Abstract: Disclosed herein is a power supply suitable for use with an airfield lighting device. In accordance with an example embodiment, there is disclosed herein, a rectifier that converts a signal from an alternating current (AC) current source to a direct current (DC) voltage. The circuit comprises a current sensor, a controller, and a half active bridge rectifier. The controller receives a signal from the current sensor and controls the operation of the half active bridge rectifier to produce a light emitting diode (LED) current based on the current sensed by the current sensor.

Abstract: A dimmer adaptable to either two (H, DH) or three (H, N, DH) active wires includes a first full-wave rectifier (D1, D2, D3, D4) across an AC power hot (H) terminal and a dimmer hot (DH) terminal and a second full-wave rectifier (D1, D4, D5, D6) across the AC power hot (H) terminal and an AC power neutral (N) terminal. The dimmer operates in a two-wire configuration by drawing power through a load when a control circuit is not conducting or in a three-wire configuration, when the AC power neutral (N) terminal is connected, by drawing power from AC power hot (H) and AC power neutral (N) terminals. The dimmer operates according to a first set of preset dim levels when current is flowing through the first rectifier and according to a second set of preset dim levels when current is flowing through the second rectifier.

Abstract: Certain embodiments provide an LED lighting equipment including a lighting main body. An LED power device has a DC power source and a DC-DC converter having an input terminal connected to the DC power source and the DC-DC converter having an output terminal. An LED light source has a board and a plurality of LED packages; each including a plurality of LED chips connected in series. The LED packages are mounted on the board and connected in series to the output terminal of the DC-DC converter.

Abstract: In a light source inverter rectifier circuits are respectively connected to a CCFL in a substantially U-shaped lamp and a CCFL in a substantially U-shaped lamp, and the outputs from the rectifier circuits are fed to a stabilization circuit. Thus, the stabilization circuit monitors an average of currents flowing through the substantially U-shaped lamps. This makes it possible to make uniform the currents flowing through the substantially U-shaped lamps.

Abstract: A ballast with end-of-life (“EOL”) protection is presented in which the voltage across a lamp at EOL is controlled to prevent the lamp from overheating, while the voltage across the lamps not at EOL is maintained to allow normal operation of those lamps, and when a new lamp is added to the ballast, the AC voltage across all lamps is controlled to allow ignition of the newly added lamp without cycling the power of the ballast.

Abstract: A lighting dimmer (52) adaptable to four wiring configurations is capable of use in serial or parallel lighting circuits and in place of two-way or three-way switches. The dimmer operates in series when one active input wire (H) is connected and in parallel when two active input wires (H, N) are connected. The dimmer is operated in place of a two-way switch by connecting one output wire (DH1) and in place of a three-way switch by connecting two output wires (DH1, DH2).

Abstract: A dimmer (42) adaptable to either two (H, DH) or three (H, N, DH) active wires includes a first full-wave rectifier (D1, D2, D3, D4) across an AC power hot (H) terminal and a dimmer hot (DH) terminal and a second full-wave rectifier (D1, D4, D5, D6) across the AC power hot (H) terminal and an AC power neutral (N) terminal. The dimmer (42) operates in a two-wire configuration by drawing power through a load (13) when a control circuit (422) is not conducting or in a three-wire configuration, when the AC power neutral (N) terminal is connected, by drawing power from AC power hot (H) and AC power neutral (N) terminals.

Abstract: An integrated DC circuit for a ceiling fan combined with a lamp is composed of a control circuit connected with a motor and a lamp, and a rectifying-filtering circuit connected with the control circuit. The rectifying-filtering circuit can alter an exterior AC power into a DC power for the motor and the lamp to use. As the motor and the lamp use the same DC power, electric leakage can be minimized to upgrade security and only a simplified structure with less material is needed, posing a reduction of cost.

Abstract: A cold cathode fluorescent lamp drive apparatus for lighting a cold cathode fluorescent lamp is disclosed. The cold cathode fluorescent lamp drive apparatus includes an abnormal current holding unit that is configured to hold an abnormal current that flows in the cold cathode fluorescent lamp, and a control unit that is configured to stop an operation of supplying a voltage to the fluorescent lamp according to the abnormal current held by the abnormal current holding unit.

Abstract: A circuit arrangement for operating at least one light source. Cost-effective power factor correction of the system input is achieved by a combination of a charge pump and a valley-fill circuit. According to the invention, the voltage (UN2) produced by the charge pump is fed into the valley-fill circuit with a lag, for example via an inductor (L2).

Abstract: An electronic ballast (100) for powering at least one gas discharge lamp (30) at two light levels includes a full-wave rectifier circuit (120) and a detector circuit (200). Detector circuit (200) provides an output voltage that is dependent on the states of two on-off switches (S1,S2), but that is substantially unaffected by typical X capacitances that are present between the hot and neutral input connections of the ballast.

Abstract: A discharge lamp lighting device includes a discharge lamp that is lighted through an L-C resonance induced by an oscillation output of an inverter circuit. An on-off operation of switching elements of the inverter circuit is controlled by a control IC which includes a timer circuit for determining a timing of conversion between operation status signals, an inverter control circuit for outputting a driving signal to the switching elements, an output control circuit for controlling generation of the driving signal and an operation status output circuit for outputting a status signal corresponding at least to a lighting status. Further, the discharge lamp lighting device includes an operation setting circuit for inputting a status signal from the operation status output circuit and outputting a control signal to the output control circuit.

Abstract: A lighting control system provides variable arc current to one or more fluorescent gas discharge lamps and provides a heating voltage to the lamp electrodes. The system includes a start-up circuit which includes circuitry for providing a starting voltage to an output power conditioning circuit. The latter drives a switching unit to control the application of DC power to the fluorescent gas discharge lamps and to provide an operating voltage to an input power factor correction circuit. The input power factor correction circuit boosts the converted DC power and the operating voltage. The start-up circuit includes a plurality of voltage doubling rectifier circuits and a plurality of zener diodes which receive the operating voltage and are electrically connected to the input power factor correction circuit and the output power conditioning unit so as to provide a regulated bias voltage supply to the output power conditioning unit and to the input power factor correction circuit.

Abstract: An electronic ballast for powering a cold cathode fluorescent lamp of an electronic display device comprising: a rectifier coupled to a source of AC power for producing a rectified DC output voltage, a power factor correction circuit receiving the rectified DC output voltage and providing an increased voltage DC bus voltage, an electronic switching circuit comprising at least one electronic switch for switching the DC bus voltage to provide a switched voltage for driving a cold cathode fluorescent lamp, the switched voltage being provided to the lamp through an output stage comprising a resonant LC circuit; and an electronic ballast control circuit for controlling a switching operation of the electronic switching circuit, the electronic ballast being provided in a housing for the electronic display device.

Abstract: A PWM driving apparatus for an LED includes a sawtooth wave generator (1) for generating a sawtooth wave signal, a comparator (2), an FET (3), a first resistor (4), a second resistor (5), a power supply (7), and a light emitting diodes array (8). A modulation signal provided by a modulation signal source (6) and the sawtooth wave signal are fed to the comparator, an output of the comparator is connected to a gate terminal of the FET, the power supply is connected to a source terminal of the FET through the first resistor, and a drain terminal of the FET outputs a driving current through the second resistor to the light emitting diodes array.

Abstract: A method an apparatus for efficiently driving a low-voltage device from a wide-range input supply uses and inductor and a diode coupled in parallel to provide a high-efficiency energy storage circuit. The parallel diode/inductor circuit is coupled to a switch for intermittently supplying a current to maintain a level of energy storage in the circuit. The switch is coupled to a control circuit for controlling the switch. The external device be a relay and the inductor may be a coil of the relay. The external device may be one or more LEDs connected in series and the diode may be the series LED circuit. The control circuit may include a fault-tolerant synchronization input for connection to multiple driver circuits, whereby audible noise produced by beat frequencies between the relays is eliminated.

Abstract: A power-saving lamp is constructed to include a lamp head, a bulb fastened to the lamp head, a polygonal light emitting circuit assembly suspended from a bracket in the lamp head within the bulb, the polygonal light emitting circuit assembly having LEDs in each of the peripheral sidewalls thereof, and a power control circuit board mounted in the lamp head and electrically connected between the lamp head and the polygonal light emitting circuit assembly to convert input AC power from the lamp head into the desired working voltage for the polygonal light emitting circuit assembly.

Abstract: In a TRIAC dimmable ballast for a discharge lamp comprising a buffer capacitor and a control circuit, a shut off circuit is incorporated for switching off the control circuit when the voltage over the buffer capacitor drops below a predetermined value due to a high phase angle adjusted in the TRIAC dimmer.

Abstract: A combination-type high frequency inverter connects an isolation leakage transformer, a smoothing condenser, a resonance condenser, a first field-effect transistor and a second field-effect transistor to a diode bridge and rectifies the voltage of an AC power source in a non-smoothing rectification manner. A load circuit has a secondary winding of an isolation leakage transformer, a fluorescent lamp and a condenser. The ‘on’ duration of the first field-effect transistor is variable. The duration of on-duty of the second field-effect transistor is fixed. Adjusting charge voltage on the smoothing condenser changes the high frequency output voltage and the load characteristics. Load characteristics, optimal for the current mode, are given to the fluorescent lamp, in accordance with whether the flourescent lamp is in either start-up or luminance mode.

Abstract: The invention relates to a circuit arrangement for operating a high-pressure discharge lamp. A buffer capacitor is shunted by a branch which comprises a series circuit of a second capactor and a unidirectional element for blocking a current with which the second capacitor charges the buffer capacitor Re-ignition after a zero crossing of the low-frequency alternating current has a comparatively high amplitude so that the lamp re-ignites in a reliable manner.

Abstract: The present invention is directed to a power supply circuit for controlling a load which, for example, includes both a gas-discharge lamp and an auxiliary load. The power supply circuit includes a ballast circuit for limiting current supplied to the gas discharge lamp. The auxiliary load, such as an occupancy sensor, is connected to receive an alternating current signal from a transformer winding, inductor coil, or other suitable portion of the ballast circuit. The power supply circuit includes a rectifier for rectifying the alternating current signal to provide a stable, low-voltage direct current signal to drive the auxiliary load.

Abstract: A half bridge driver chip for driving a resonant load, such as a ballast, has first and second pairs to which an oscillation frequency timing circuit, matched to the resonant frequency of the load. A constant voltage drop circuit is connected to these input pins to vary the voltage at the pins as a linear function of the input voltage V.sub.cc. Consequently, when V.sub.cc is increasing during the start-up of the circuit, the resonant frequency is initially high but decreases to its operation value as V.sub.cc increases. This produces a soft start characteristic and a timed preheat cycle of the resonant load. In one embodiment, the constant voltage drop circuit is a zener diode; in another embodiment, it is strings of anti-parallel connected diodes.

Abstract: An improved fluorescent light ballast circuit extends the on/off life of a florescent lamp within a lighting circuit having a pair of series connected fluorescent lamps. The ballast circuit includes a DC pulse generation circuit, filtering and voltage regulation circuitry, a step-up voltage transformer, and a current altering circuit which alters the current within selected filaments within the lamps. The current altering circuit includes a diode and a coil winding which connect across a filament within one of the fluorescent lamps. The net effect of the current altering circuit is to increase the voltage supplied across the lamp connected to the current altering circuit so that the voltage levels across both lamps are balanced.

Abstract: A modified valley fill circuit, including a main ballasting inductor for supplying an electrolytic capacitor, has an additional charging winding on the main ballasting inductor for charging the electrolytic capacitor to a predetermined voltage which maximizes the power factor of the input current by optimizing the conduction angle of the input current. In a discharge lamp ballast, the modified valley fill circuit reduces the lamp current crest factor by controlling the frequency with a lamp current control loop.

Abstract: A ballast for a gas discharge lamp circuit has a d-c output which contains three series-connected diodes connected across the output terminals, a pair of capacitors connected from different respective nodes of the diodes to respective ones of the output terminals, and a resistor connected between two of the diodes. The resistor increases the circuit power factor to greater than 0.95.

Abstract: A fluorescent lamp is connected in parallel with the tank capacitor of a resonant L-C circuit series-excited by a 30 kHz voltage from a self-oscillating inverter. The inverter's DC supply voltage is at certain times obtained directly from unfiltered full-wave-rectified 120 Volt/60 Hz power line voltage and at certain other times from an energy-storing capacitor kept charged to a given voltage level by up-conversion from the unfiltered full-wave-rectified rectified power line voltage. The up-conversion is accomplished via a FET transistor switched at 30 kHz with a gate-drive derived from the L-C circuit. Whenever the magnitude of the DC supply voltage exceeds a predetermined level, the gate-drive voltage ceases to be provided and the up-conversion process ceases. Whenever up-conversion does take place, the magnitude of the current drawn from the power line is proportional to the instantaneous magnitude of the power line voltage.

Abstract: In a microwave oven, a magnetron is powered by way of a self-oscillating flyback converter circuit, which operates at a conversion frequency controllable over a range of frequencies up to about 35 kHz. The converter circuit is powered from a DC voltage derived from full-wave-rectification and filtering of ordinary 120 Volt/60 Hz power line voltage. The output of the converter is applied to the magnetron by way of a flyback transformer.In one preferred configuration, the output fromthe flyback transformer is applied dirrectly to the magnetron--without the use of an intermediary rectifier. As a result, current to the magnetron is provided inthe form of triangularly-shaped pulses with a duty-cycle of about 60% and with a crest-factor of less than 3.5.In a second preferred configuration, the output from the flyback transformer is rectified and filtered by a capacitor-inductor combination, with the result of providing a nearly constant-magnitude current to the magnetron.

Abstract: A circuit arrangement for A.C. operation of gas discharge lamps comprises a full-wave rectifier (1) connected to an alternating voltage source. The direct voltage is supplied to a combinatorial circuit part (3 to 8) in the form of a direct voltage converter, to which is connected a bridge circuit (9) which comprises four thyristors. The transverse branch of the bridge circuit includes the lamp (5). The full-wave rectifier (1) is followed by a smoothing capacitor (2) and an electronic switching element (14) is connected parallel to the bridge circuit (9). The switching element is switched to the conducting state in the vicinity of the zero passages of the input alternating voltage. As a result shortcircuits in the bridge circuit are avoided.

Abstract: A load is provided, at all times when in operation, with a D.C. voltage having at least a minimum holding magnitude by: providing a source voltage having a peak magnitude greater than the holding magnitude; connecting the source voltage to the load only while the source voltage magnitude is greater than a preselected magnitude; charging from the peak source voltage magnitude an energy storage element while the load is connnected to the source voltage; energizing the load from the charged energy storage element whenever the source voltage magnitude is less than the preselected magnitude; increasing the effective impedance of the load whenever the load is energized by the storage element; and selecting the energy storage element to provide at least the holding voltage to the load during each time interval when the energy storage element is connected to the load.

Abstract: A high intensity discharge lamp operable from an AC potential source includes an arc discharge tube having a pair of oppositely disposed main electrodes therein and an associated external starting electrode, all disposed within a sealed envelope having an affixed base with a circuit means including a negative potential blocking device coupling the starting electrode to the AC potential source.

Abstract: A circuit is provided for regulating the application of power to a load which is relatively insensitive to rapid power fluctuation of the type exemplified by typical AC line sources. In one embodiment, an AC line source is applied at a controlled rate to a tungsten lamp whose operation is controlled by a transistor switching network. The transistor operation, in turn, is controlled by comparing a portion of the rectified signal with a signal proportional to the light output of the lamp.

Abstract: High frequency circuit for operating gaseous discharge lamps includes oppositely poled controlled semiconductor switches connected to a resonant circuit comprising a capacitor and inductor connected to the lamp load and serving both as a high-frequency ballast for the lamp and to effect alternating turn-off of the semiconductor switches. Diodes are connected to the switches in a manner to provide energy pulses on the lamp load without return to the supply source. A control circuit is provided for alternately triggering the semiconductor switches into operation.

Abstract: A circuit is disclosed which is suitable for controlling lighting in a building from a multiple number of points. AC current to light bulbs is controlled by a triac which in turn is controlled by the output of an optical coupler which is controlled by the output of a logic device. The output of said logic device is connected to control the input to the triac. Switches connecting to the input of the logic device each can independently determine energization or deenergization of the light bulbs.

Abstract: Color properties of high pressure sodium vapor discharge lamps are improved by disclosed operating circuit for applying pulsed direct current to the lamp. The circuit comprises a direct current supply circuit, a transistor switch in series with the lamp and the primary of a transformer connected across the supply circuit, a diode in series with the secondary of the transformer connected across the supply circuit, and SCR switch connected across the secondary of the transformer, and a control circuit connected to the switches for applying DC pulses to the lamp at a predetermined repetition rate and duty cycle. The circuit produces pulse waveforms which provide substantial color improvement in the lamp and makes efficient use of the energy supplied from the power source.

Abstract: A lighting control apparatus to provide variable intensity light from high pressure discharge lamps using two high pressure discharge lamp loads connected in series to provide more widely variable intensity of light. The outputs of two ballasts may be connected in series to feed the series connected discharge lamp load. Preferably a feedback signal proportional to load current is used to stabilize operation. In addition, circuitry is preferably provided to maintain a predetermined minimum current to prevent extinguishing of the lamps from low current and "hot restrike" circuitry is provided to limit the maximum load voltage when the lamps are extinguished.

Abstract: Operating circuit for gaseous discharge lamps, such as those of metal vapor type, having a ballast device of conventional type is provided with high voltage generating means for applying high voltage starting pulses on the lamp. The circuit may be combined with an auxiliary incandescent lamp for turning the latter on for safety lighting purposes when the gaseous discharge lamp goes out. The circuit includes an induction coil in series with the gaseous discharge lamp, a controlled switch connected to a tap on the induction coil, and a charging capacitor in series with the controlled switch. When used, the incandescent lamp is connected in series with the controlled switch in parallel with the charging capacitor.