Abstract: A welding or additive manufacturing power supply includes output circuitry configured to generate a welding waveform, a current sensor for measuring a welding current generated by the output circuitry, a voltage sensor for measuring an output voltage of the welding waveform, and a controller operatively connected to the output circuitry to control the welding waveform, and operatively connected to the current sensor and the voltage sensor to monitor the welding current and the output voltage. A portion of welding waveform includes a controlled change in current from a first level to a second level different from the first level. The controller is configured to determine a circuit inductance from the output voltage and the controlled change in current, and further determine a change in resistance of a consumable electrode in real time based on the circuit inductance.

Abstract: A power control circuit includes an alternating current (AC) power source, a rectifier and a valley-fill circuit. The AC power source is configured to receive an AC voltage. The rectifier is configured to convert the AC voltage into a rectified voltage. The valley-fill circuit includes: an inductor, having a first terminal coupled to the rectifier, and a second terminal; a first resistor, having a first terminal coupled to the second terminal of the inductor, and a second terminal; a diode, having a cathode coupled to the second terminal of the inductor, and an anode; and a first capacitor, having a first terminal coupled to the second terminal of the first resistor and the anode of the diode, and a second terminal coupled to ground.

Abstract: An ultraviolet lamp system is provided. The ultraviolet lamp system includes: (a) a bulb; (b) at least one magnetron configured to emit microwave energy configured to be received by the bulb; and (c) a power supply configured to provide electrical energy to the at least one magnetron, the power supply being adapted to modulate the electrical energy provided to the at least one magnetron such that light output from the bulb is more uniform in at least one of intensity and spectral output.

Abstract: Aspects of the disclosure provide a circuit. The circuit includes a control circuit and a return path circuit. The control circuit is configured to operate in response to a first conduction angle of a dimmer coupled to the circuit. The first conduction angle is adjusted to control an output power to a first device. The dimmer has a second conduction angle that is independent of the control of the output power to the first device. The return path circuit is configured to provide a return path to enable providing power to a second device in response to the second conduction angle.

Abstract: An illumination device (1) comprises: input terminals (2) for coupling to AC mains; a LED string (10) connected in series with the input terminals; a rectifier (30), having input terminals connected in series with the LED string; a controllable voltage source (40), having input terminals coupled to the rectifier output terminals; a series arrangement of at least one auxiliary LED (51) and a second ballast resistor (52) connected to the output terminals of the controllable voltage source. The voltage source comprises: a series arrangement of an adjustable first resistor (46) and a second resistor (47) connected in parallel to the input terminals; a tuneable Zener diode (49) connected in parallel to the output terminals, having a control input terminal (48) connected to the node between the two resistors; wherein positive output terminal is connected to positive input terminal and negative output terminal is connected to negative input terminal.

Abstract: The present invention is directed to a fluorescent light fixture assembly including a ballast and a novel lighting element that includes an array of LEDs and at least one converter module that enables the existing ballast providing an AC power input to supply DC power to the LED array. The lighting element includes a body that contains the LED array and the converter modules and shares the configuration of the lighting element that is to be retrofitted. The lighting element receives power from the pre-existing ballast, wherein the converter module provides a constant current source to power the LED array. Thus, the lighting element, including the converter module, replaces the conventional fluorescent light tube in a cost-effective retrofit manner with the existing ballast.

Abstract: A driving circuit for a solid state lighting apparatus includes a full wave rectifier configured to rectify an alternating current (AC) input voltage signal to generate a rectified input signal, a boost conversion circuit configured to receive the rectified input signal and responsively generate a direct current (DC) output voltage signal and to supply the output voltage signal to a solid state light source, and a boost control circuit coupled to the boost conversion circuit and configured to cause the boost conversion circuit to operate in a constant power mode.

Abstract: A passive anti-arcing protection components for electronic ballasts of fluorescent lamps. This protection component is a bridge-rectifier-resistor-capacitor network, containing at least a diode, a resistor, and a capacitor. The component's circuitry is electrically connected to the ballast at the lamp side, acting as a low-resistance redirection path for any sudden change in energy. When an arcing condition is about to occur, this protection circuitry absorbs the spark energy, ceasing the arcing condition.

Abstract: A method for operating a high pressure discharge lamp, with the high pressure discharge lamp being operated by a current inverter with a square wave lamp current having a positive phase with positive current flow and a negative phase with negative current flow, and with the current inverter being controlled by a control arrangement wherein the method comprises the steps of measuring a value for the positive current flow representing the lamp wattage or the square wave lamp current, measuring a value for the negative current flow representing the lamp wattage or the square wave lamp current; calculating a predetermined setpoint value in each case from a guide variable of a lamp wattage or of the square wave lamp current and the measured value for the phase with positive current flow; calculating a predetermined setpoint value in each case from a guide variable of a lamp wattage or of the square wave lamp current and the measured value for the phase with negative current flow; and outputting the two predetermin

Abstract: In various embodiments, a device for controlling power supply towards at least one light source comprising a load having a value variable as a result of switching of at least one switch coupled thereto, is provided. The device may include: a power supply set controllable to determine the intensity of the current fed towards said load; a current feedback loop sensitive to the intensity of the current fed towards said load, said current feedback loop connected to said power supply set to maintain the intensity of the current fed towards said load upon variation of said load; and a voltage control sensitive to the voltage across said load, said voltage control likewise connected to said power supply set to maintain the intensity of the current fed towards said load upon variation of said load.

Abstract: A power supply for use in a UV curing lamp assembly is disclosed. The power supply is powered by two intermediate frequency (200-400 Hz) low voltage sinusoidal power sources that drive the primary windings of a dual laminated transformer. The low voltage sinusoidal power sources are configured to have different phases. The out-of-phase low voltage sine wave sources are converted to high voltage sine waves on the secondary windings of the dual laminated transformer having the same phase difference relationship. A single rectifier comprising six high voltage diodes, called a ladder rectifier, combine the two out-of-phase sine waves into a single, approximately DC output power source. By modulating a phase difference between two input sine wave power sources, the approximate DC output voltage exiting the ladder rectifier may be alternated between a low ripple mode of about a 13.84% ripple, a high current mode, a high voltage mode, and an intermediate mode with a ripple in the range of about 13.84% to about 100%.

Abstract: An energy efficient apparatus includes a switching device, a frequency dependent reactive device, and a control element is provided. The switching device is coupled to a source of electrical power and includes a pair of transistors and is adapted to receive a control signal and to produce an alternating current power signal. The frequency of the alternating current power signal is responsive to the control signal. The frequency dependent reactive device is electrically coupled to the pair of transistors for receiving the alternating current power signal and producing an output power signal. The frequency dependent reactive device is chosen to achieve a desired voltage of the output power signal relative to the frequency of the alternating current power signal. The control element senses an actual voltage of the direct current power signal and modifies the control signal delivered to achieve the desired voltage of the direct current power signal.

Abstract: A driving circuit for a LCD backlight source comprising a BOOST structure which comprises a capacitor C12, a capacitor C13, an inductor L2, a diode D2, and a MOSFET, wherein the driving circuit further comprises a capacitor C11, a capacitor C14, a diode D3, and a diode D4. One terminal of the diode D3 is connected to one terminal of the capacitor C13, and the other terminal is connected to one terminal of the diode D4; the other terminal of the diode D4 is connected to one terminal of the capacitor C14 which is the output terminal of the circuit, and the other terminal of the capacitor C14 is grounded; one terminal of the capacitor C11 is connected between the inductor L2 and the diode D2, and the other terminal of the capacitor C11 is connected between the diode D3 and the diode D4.

Abstract: A driver device for driving an LED lighting device includes at least one power switch adapted to operate at a switching frequency of greater than 500 KHz and adapted to control the driving current provided to the LED lighting device. Operating the power switch at such a high frequency allows a substantial reduction in passive devices such as inductors and capacitors.

Abstract: A discharge lamp drive device for driving a discharge lamp including a first electrode and a second electrode, include: a power supply unit which supplies alternating power to the discharge lamp by inputting alternating current between the first electrode and the second electrode, wherein the power supply unit includes a power reduction control unit which reduces the alternating power from a first level to a second level lower than the first level, and a duty ratio control unit which steppedly varies duty ratio of the alternating current in a predetermined period at the time of reduction of the alternating power.

Abstract: The invention relates to electric lighting facilities powered from an external electrical network. The light-emitting diode lamp comprises a step-down voltage converter (1) made up of a chain of capacitors (2, 3, 4) connected in series, one of which is a power take-off capacitor (3) and is connected to at least one pair (5) of inverse-parallel connected light-emitting diodes (6, 7). The invention makes it possible to achieve extremely low electrical energy consumption for lighting, ensure optimum performance, and use the circuit for the additional function of supplying power to external users of, for example, mobile telephones.

Abstract: A circuit arrangement for operating a low-pressure discharge lamp may include a voltage source with two terminals; switches; and a series resonant circuit; a controller configured to control the switches such that an AC voltage is applied to the resonant circuit; a PTC thermistor coupled on one side to a circuit point of the resonant circuit and on the other side, at least one of via a diode, to the first terminal of the voltage source and, via a diode to the second terminal of the voltage source; a resistive element connected in series with a diode in the circuit between a terminal of the voltage source and the PTC thermistor; and an evaluation device configured to tap off the voltage drop across the resistive element and being coupled to the controller in order to deactivate the controller.

Abstract: A series connected light string using LEDs connected to an AC power source is disclosed. In order to make some or all of the lights color change, twinkle, and/or flash, controllers are provided in series with all or some of the LEDs. Because the supply source AC, but the active elements are essentially rectifiers, the circuit becomes a half wave DC circuit. Half wave DC will cause unpredictable behavior in DC circuit components. This will cause the controller to shut down during the zero voltage portion of the pulsating DC cycle. To prevent this a current supplying element is placed in parallel with the controller.

Abstract: An enhanced control mechanism for an LED light string system is provided for switching between one of two DC output phases or polarities so as to actuate one or the other of two LEDs within the bulbs on the light string. The control mechanism is further configured to allow switching so as to pass through the input power provided by a light string that is plugged into its electrical power feeding end. The control mechanism may provide either AC, rectified AC, or DC voltage of various values to the LED string according to the particular needs of the LED bulbs.

Abstract: A light emitting element lighting device includes: a rectifying unit which rectifies an AC voltage; a smoothing unit which smoothes a ripple voltage from the rectifying unit; a power supply unit having a switching element; and a control unit which controls on/off of the switching element. Further, the smoothing unit servers as a partial smoothing circuit for partially smoothing a low voltage period of the ripple voltage outputted from the rectifying unit. The power supply unit supplies a lighting power to a light source unit including one or more light emitting elements. The control unit controls a switching frequency of the switching element to decrease as the output voltage of the smoothing unit decreases.

Abstract: An LED power supply device may include a power supply to control an LED component, a control unit to control the power supply, the control unit having a control interface for applying external control signals to the power supply, and a voltage supply unit connected to a connection of the power supply, wherein the control unit receives operating voltage from the voltage supply unit for continuous operation in an activated and non-activated control state of the LED component, wherein the voltage supply unit comprises a capacitor coupled to an output side of the power supply, the capacitor configured to supply a capacitor voltage as operating voltage to the LED power supply device, and wherein the control unit is configured to charge the capacitor using pulse-like control of the power supply such that, in the non-activated control state, a maximum charging voltage lies below the LED threshold voltage.

Abstract: A light-emitting module may be configured to have improved light emission efficiency and light distribution characteristics. A light-emitting module may include a substrate having a front surface side as a component mounting surface and a rear surface side as a flat heat dissipating surface, a plurality of light-emitting elements arranged in a manner protruding at a central portion of the component mounting surface of the substrate. The light-emitting elements may radiate light at least in an upper surface direction and in a direction along the component mounting surface. The module may further include one or more lighting circuit components electrically connected to the light emitting elements by a wiring pattern arranged on the substrate and which is arranged closer to the peripheral edge side of the substrate than the light emitting elements on the component mounting surface of the substrate, and a connector for power supply connection.

Abstract: A solid-state light engine comprised of light emitting diodes (LEDs) configured into a bridge rectifier with a current limiting module coupled to the LED bridge rectifier. The light engine may be packaged for high temperature operation. Optionally, the LEDs comprise wavelength-converting phosphors with a persistence that is a multiple of the peak to peak current period, to smooth and mask ripple frequency pulsation of emitted light.

Abstract: The invention relates to a discharge lamp with a floor plate and a roof plate designed for dielectrically impeded discharge, in which the minimum discharge distances are at least 10 mm.

Abstract: A light emitting diode (LED) device comprises a base and a cover packaging of a rectifier diode chip and a light emitting diode chip connecting in series with a metal wire. The LED device can be plugged directly into the socket of the LED light string without any other external rectifier circuits. Moreover, the device has advantages of small size, easy-to-use and easy-to-change. By adopting different connection methods with the LED device, it can achieve anticipative functions, such as half-wave, full-wave and bridge rectifier, etc.

Abstract: Solid state light source driving and dimming systems are provided that enable a plurality of solid state light source (e.g., LED) driver circuits to be coupled to a single AC voltage source. The driver circuits may include constant current circuitry configured to generate a constant AC current from the AC voltage source, and rectifier circuitry configured to generate a DC current to drive the solid state light source (e.g., LEDs). Dimming control includes shunt circuitry operable with a PWM switch to shunt the AC voltage source during certain portions of a PWM signal and to decouple the shunt circuitry from the AC voltage source during other portions of the PWM signal. Shunting the AC voltage source causes the interruption of the DC current to effectively turn off the LEDs. Decoupling the shunt circuitry may improve overall efficiency of power transfer to the LEDs.

Abstract: A passive anti-arcing protection components for electronic ballasts of fluorescent lamps. This protection component is a bridge-rectifier-resistor-capacitor network, containing at least a diode, a resistor, and a capacitor. The component's circuitry is electrically connected to the ballast at the lamp side, acting as a low-resistance redirection path for any sudden change in energy. When an arcing condition is about to occur, this protection circuitry absorbs the spark energy, ceasing the arcing condition.

Abstract: Embodiments of the invention provide for a linear lighting system with a plurality of discrete light sources. Other embodiments of the invention include heat dissipation techniques and apparatus for a linear light system. Other embodiments of the invention include a two component lighting system that includes rails and nodes. In some embodiments, the lighting and control aspects can be divided between the rail and node. In yet other embodiments a linear lens providing a unique photometric distribution is provided.

Abstract: A driver device for driving an LED lighting device includes at least one power switch adapted to operate at a switching frequency of greater than 500 KHz and adapted to control the driving current provided to the LED lighting device. Operating the power switch at such a high frequency allows a substantial reduction in passive devices such as inductors and capacitors.

Abstract: A VFD drive apparatus in which the filament of a VFD is coupled at a first terminal to an input voltage derived from a voltage source, and at a second terminal to a shunt voltage regulator that establishes a regulated filament current and a regulated cutoff voltage with respect to ground potential. Other electrical loads such as drive circuitry for the anodes and grid of the display are coupled between the second terminal of the filament and ground potential so that at least a portion of the filament current is supplied to such other electrical loads. Power dissipated by the shunt voltage regulator is thereby reduced, and the cost associated with providing additional voltage regulators for the other electrical loads is avoided.

Abstract: A fluorescent lamp adapted for effecting stepless dimming with a regular SCR dimmer, comprising a filter and rectifier circuit (1), a DC high voltage stabilizing circuit (2), a voltage signal detection and frequency control circuit (6), a lamp load (4), a lamp current feedback circuit (5) and a voltage signal sampling circuit (3) thereby changing the power factor and luminous intensity of the lamp in accordance with the variation of the conduction phase angle of the silicon controlled rectifier dimmer. The present invention solves the discontinuity and instability issues in course of dimming operation and is particularly adapted for use in an integrated compact fluorescent lamp.

Abstract: A driving device for driving a light source module (12), includes an inverter circuit (15) for converting a received signal to a signal driving the light source module, a feedback and filter circuit (13) for feeding back currents flowing through the light sources and filtering radio frequency interference (RFI) signals of feedback currents, and a controller (14) electrically connected between the feedback and filter circuit and the inverter circuit. The feedback and filter circuit includes at least one filter for filtering the RFI signals of the feedback currents, and a resistor (R) for feeding back the current flowing through the light source module. The filter includes an impedance (Z11) including a first terminal designated as an input of the filter and a second terminal, and a capacitor (C11). The capacitor includes a third terminal designated as an output of the filter and a fourth terminal electrically connected to ground.

Abstract: A discharge lamp ballast apparatus includes a DC/DC converter having a transformer T1 and a DC/DC converter having a transformer T2, which are connected in parallel; a control section 4 for controlling the output voltages of the DC/DC converters by varying their duties with shifting the operation phases of the transformers T1 and T2 of the DC/DC converters; and a voltage-multiplier rectifier circuit having diodes 7-9 and capacitors 10-12 for generating a high voltage used for starting a discharge lamp 22 by utilizing the potential difference between the output voltages of the transformers T1 and T2.

Abstract: A single-stage electronic ballast device outputs a square wave current to drive an HID lamp, which includes a rectifying and power factor correction unit, a bridge converter and a controller circuit. The rectifying and power factor correction unit has an input connected to an AC power source to rectify an AC power to a DC power. The bridge converter comprises two bridge arms formed by four switches, load terminals defined by midpoints of the two bridge arms and the HID lamp is connected between the load terminals. The bridge converter converts DC current to square wave current to drive the HID lamp with power control. The load terminals are selectively connected to output of the rectifying and power factor correction unit to adjust waveform of input current for higher power factor. The controller circuit has output connected to DC link voltage terminal and load terminal of the bridge converter.

Abstract: Disclosed is a low cost LED string circuit design that uses an inexpensive half-wave rectification and low-pass filter circuit that is designed to produce minimal flicker in the LED string that is connected to the circuit. The components of the half-wave rectification and low-pass filter circuit are selected in accordance with design principles that prevent glittering and flickering of the LED string. The circuit components of the half-wave rectification and low-pass filter circuit can be embedded in an outlet plug or as a separate independent unit between an AC power plug and the LED string.

Abstract: The present invention relates to a LED lamp set apparatus, comprises a gas discharge tube and a LED connected in series, the gas discharge tube is a neon tube, an argon tube, a helium tube or a krypton tube, or a gas tube in which the other inert gases is filled or is filled with a mixture of inert gases. When operating the LED lamp set apparatus provided by the present invention, a public AC power source can be directly input to the LED lamp set apparatus for lighting the LED, needless of an inverter; for protecting the LED, the LED lamp set apparatus can be connected in series with a current-limiting resistance, or the public AC power source can be input to a rectifying diode or a bridge rectifier for processing a rectifying operation and then input to the LED lamp set apparatus; a plurality of the LED lamp set apparatuses can be connected in parallel; or the LED lamp set apparatus can be integratedly-packaged and is inserted to a connector.

Abstract: A fluorescent lamp adapted for effecting stepless dimming with a regular SCR dimmer, comprising a filter and rectifier circuit (1), a DC high voltage stabilizing circuit (2), a voltage signal detection and frequency control circuit (6), a lamp load (4), a lamp current feedback circuit (5) and a voltage signal sampling circuit (3) thereby changing the power factor and luminous intensity of the lamp in accordance with the variation of the conduction phase angle of the silicon controlled rectifier dimmer. The present invention solves the discontinuity and instability issues in course of dimming operation and is particularly adapted for use in an integrated compact fluorescent lamp.

Abstract: A method of polymerizing by a free radical polymerization mechanism, product formed thereby, and apparatus for performing this method, are disclosed. The composition to be polymerized by the free radical polymerization mechanism is irradiated by a substantially constant radiation, the radiation being substantially without pulsation. The use of the substantially constant radiation without pulsation reduces premature termination of the polymerization. The substantially constant radiation can be the output of a lamp powered by a constant current, direct current power supply.

Abstract: An image display apparatus having a plurality of image forming devices. In an output circuit provided between constant voltage supplies and wiring for driving each of the image forming devices, MOSFETs are successively turned on from the one having a higher ON resistance at the time of switching to make a stepwise transition between outputs from the constant voltage supplies, and have steady potential, thereby limiting undesirable variation in signal potential at the time of switching.

Abstract: An improved decorative light string circuit comprises full bridge rectification located in or downstream of the front plug, wherein the rectification circuit contains one or more voltage reducing and/or filtering elements in order to reduce or limit LED drive current and reduce (filter) DC ripple and 1 or 2 LED series sets. Additional rectification circuits and LED series sets can be added in parallel to the first in “stacked mode”, with each rectification circuit and LED series set electrically independent of prior and subsequent circuits. This eliminates the rectifying diode current summation load restrictions imposed by prior art and associated safety hazard due to diode overheating.

Abstract: A fixed phase power controller that converts a line voltage to an RMS load voltage includes an analog control block with a capacitor that receives an input that is independent of a change in magnitude of the line voltage and that charges and discharges to provide a trigger signal at a first frequency, a reset circuit that periodically resets an initial condition of the analog control block, a synchronization connection that provides a sync signal that synchronizes the trigger signal with a waveform of the line voltage, and a control circuit that clips a load voltage based on the synchronized trigger signal to define the RMS load voltage. The controller finds application in a lamp where it reduces the line voltage to an RMS load voltage suitable for a light emitting element.

Abstract: A reliable and efficient circuit for lighting a discharge lamp is described. An inverter accepts a direct current supply voltage and outputs an alternating current lamp voltage to drive the discharge lamp at a relatively high frequency. In one embodiment, the inverter includes semiconductor switches in a full-bridge configuration, a transformer feedback circuit to control the semiconductor switches, and a series L-C resonant circuit. In one embodiment, the inverter includes semiconductor switches in a half-bridge configuration, a transformer feedback circuit to control the semiconductor switches, and a series L-C resonant circuit. The inverter can drive multiple discharge lamps in a parallel configuration. A bypass circuit can also be coupled across a cathode of the discharge lamp to extend the life of the discharge lamp. The bypass circuit activates when a lamp cathode wears out.

Abstract: A current-regulating driver circuit for a light emitting diode (LED) maintains energization drive to and thereby illumination provided by the LED at a prescribed, substantially constant value, over a relatively wide range of input (AC or DC) voltage. First and second input nodes are coupled to a source of AC or DC voltage and to a load, powered by the source of AC or DC voltage. An input rectifying diode is coupled to the first input node. A controlled current flow element is coupled in a first current flow path between the input rectifying diode and the LED and is controllably operative to supply current for illuminating the LED.

Abstract: An ionizing discharge device operating arrangement wherein initiation of discharges in for example a dielectric barrier discharge device is accomplished by a short circuit shunting of the charged electrodes of the device. A cycle of slow charging of the device inter-electrode capacitance followed by a high-speed electrode-shunting event is used for continuing operation of the device. In this operating cycle energy storage is accomplished by the inter-electrode capacitance of the device without causing ionization by way of a controlled rate of capacitance charging accomplished without assistance of additional storage elements. Desirable fast pulse rise-time energization characteristics are achieved in the dielectric barrier discharge device by way of using a fast, preferably electronic, switch in the shunting operation and maintaining the discharge in a circuit of relatively low inductance and minimal lead lengths.

Abstract: Improved method and apparatus for hand-held portable illumination. A flashlight and corresponding method are described. The flashlight includes a housing, a plurality of LEDs, and an electrical circuit that selectively applies power from the DC voltage source to the LED units, wherein the flashlight is suitable for handheld portable operation by a user. In one embodiment, the first electrical circuit further includes a control circuit for maintaining a predetermined light output level of the LED units as a charge on a battery varies. In another embodiment, the control circuit maintains an average predetermined light output level of the LED units as the charge on the battery cell varies by changing a pulse width or frequency as the charge on the battery cell varies to maintain a given average light output.

Abstract: A device for operating a dielectric barrier discharge lamp in which not only the efficiency is maintained, but in which a reduction of the irradiance over the course of use is advantageously prevented. The device includes a dielectric barrier discharge lamp and a feed device for applying a high voltage to this dielectric barrier discharge lamp, wherein the feed device via a set-up transformer applies a high voltage with an essentially periodic waveform to the barrier discharge lamp. Moreover, the applied high voltage first produces a steep rising waveform and then ringing, wherein the ratio of the difference between a second extreme value point and a third extreme value point to the difference between a first extreme value point and the second extreme value point of the ringing is less than or equal to 30%. It is a further object of an embodiment of the present invention to reduce or eliminate the ringing.

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: 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: A filament cut-back circuit is disclosed. The filament cut-back circuit comprises an impedance circuit coupled in series between either an AC voltage source and a primary filament winding, or a secondary filament winding and a filament. In response to an alternating voltage from the AC voltage source when coupled in series thereto or an alternating voltage from the secondary filament winding when coupled in series thereto, the impedance circuit operates as a short circuit when the alternating voltage is at a preheat frequency and operates as an open circuit when the alternating voltage is at an operating frequency.

Abstract: A dimming control system includes a first circuit (100) and a second circuit (200). First circuit (100) is coupled in series with the AC line source (10) and receives brighten and dim commands from a user. The brighten and dim commands are communicated to second circuit (200) by momentarily altering the AC voltage waveforms observed by second circuit (200). Second circuit (200) provides an adjustable dimming control voltage that is coupled to existing dimming control circuitry within an electronic dimming ballast. The dimming control voltage is adjusted by the second circuit (200) in dependence on the observed AC voltage waveforms.