Abstract: A DC/DC converter is described that can output power during both an on-period and an off-period of a switching element. The DC/DC converter may have a transformer and a switching element that may be turned on and off to connect or cut off the primary coil of the transformer. A first rectification device connected between the secondary coil of the transformer and an output terminal makes a first current on a path from the input terminal to the output terminal via the secondary coil to flow during an on-period, and cuts off the first current during an off-period. A second rectification device connected between the primary coil and the output terminal cuts off a second current on a path from the input terminal to the output terminal via the primary coil during the on-period, and makes the second current to flow during the off-period.

Abstract: A system for identifying the location of the mobile device uses standard fluorescent light fixtures commonly found in indoor environments and detects minor variations in the light output of those fixtures caused by normal manufacturing variation. These variations are catalogued as identifying fingerprints together with location of the light fixtures to provide for navigation.

Abstract: The present disclosure relates to a method and apparatus for controlling an illumination device, such as a light bulb, LED light, or the like. In one embodiment, a lighting control adapter is described, comprising a male base for physically attaching the lighting control adapter to a light fixture and for receiving power from the light fixture via a light switch connected to the light fixture, a female socket for receiving a base of an illumination device, a switching circuit for providing switchable power to the illumination device, and a processing circuit coupled to the switching circuit, for detecting one or more power toggles of the power received by the male base, and for controlling illumination of the illumination device based on the detection of one or more detected toggles.

Abstract: In some implementations, a device that powers a load includes a first terminal to couple with an alternating current (AC) power source, a second terminal to couple with the AC power source, and a full bridge rectifier arranged to receive power from the AC power source and provide direct current (DC) power between a positive node and a negative node. The device includes a first capacitor coupled in series between the full bridge rectifier and the first terminal or the second terminal, a load coupled between the positive node and negative node of the rectifier, and a second capacitor coupled between the positive node and negative node of the rectifier, in parallel with the load.

Abstract: A single-phase DC/AC inverter has a single-phase inverter bridge with binary switches connected to an RLC low-pass filter. Digital control logic in a control circuit (or in a microcontroller) determines and controls a logic state q determining the position of the switches in the inverter bridge from sensed iL, vC values from the RLC filter. The control logic selects one of multiple possible logic states q based on whether the sensed iL, vC values belongs one of multiple boundary regions of a tracking band in an iL, vC state space.

Abstract: A three-level chopper apparatus includes a protection switch circuit that changes a current pathway through which an overvoltage is applied to a second capacitor or a first capacitor to a current pathway through which no overvoltage is applied to the second capacitor or the first capacitor when a first switch or a second switch has a failure.

Abstract: A flash heating part in a heat treatment apparatus includes 30 built-in flash lamps, and irradiates a semiconductor wafer held by a holder in a chamber with a flash of light. Thirty switching elements are provided in a one-to-one correspondence with the 30 flash lamps. Each of the switching elements defines the waveform of current flowing through a corresponding one of the flash lamps by intermittently supplying electrical charge thereto. Radiation thermometers measure an in-plane temperature distribution of the semiconductor wafer during flash irradiation. Based on the results of measurement with the radiation thermometers, a controller individually controls the operations of the 30 switching elements to individually define the light emission patterns of the 30 flash lamps.

Abstract: A wireless charging system uses a transformer to adjust output voltage of the charging antenna to reduce the voltage in the resonant capacitor for a wireless charging coupling.

Abstract: A digital flashlamp controller, a flashlamp control system and a method of controlling a flashlamp bulb employing digital control electronics are provided herein. In one embodiment, the digital flashlamp controller includes: (1) a trigger interface configured to provide firing signals to control a trigger element for a flashlamp bulb and (2) digital electronics configured to generate the firing signals and control multiple pulsing of the flashlamp bulb.

Abstract: A thermal management system for reducing or eliminating heat-mediated degradation of LED performance and/or operating life. The system may include a thermal controller arranged to respond to an LED operating condition, and to responsively limit temperature in the LED. The thermal controller in one implementation includes a bypass circuit containing a bypass control element, such as a varistor, Zener diode, or antifuse device, and arranged to divert current from flowing to the LED so that the LED remains in a cool state, e.g., below 75° C. The system may be arranged to (I) at least partially attenuate the power supplied to an LED so as to reduce heat generation in such LED and maintain the LED below a threshold temperature and/or (II) remove heat from the LED to maintain temperature of the LED below a threshold temperature.

Abstract: System and method for protecting a power converter. A system includes a threshold generator configured to generate a threshold signal, and a first comparator configured to receive the threshold signal and a first signal and to generate a comparison signal. The first signal is associated with an input current for a power converter. Additionally, the system includes a pulse-width-modulation generator configured to receive the comparison signal and generate a modulation signal in response to the comparison signal, and a switch configured to receive the modulation signal and adjust the input current for the power converter. The threshold signal is associated with a threshold magnitude as a function of time. The threshold magnitude increases with time at a first slope during a first period, and the threshold magnitude increases with time at a second slope during a second period. The first slope and the second slope are different.

Abstract: A motor drive device includes a constant voltage power supply and a motor drive control unit. The constant voltage power supply includes an AC/DC converter, a zero-cross detector, a switching control unit and a switching regulator. The AC/DC converter converts an AC voltage supplied from an AC voltage source into a DC voltage. The zero-cross detector detects a zero-cross point of the AC voltage, and outputs a zero-cross detection signal. The switching control unit outputs a switching control signal based on the zero-cross detection signal. The switching regulator has a switching element. The motor drive control unit outputs a motor drive signal for driving a motor to the inverter. The AC/DC converter has a rectifier circuit and a smoothing capacitor. The switching regulator performs switching on a first DC voltage in accordance with the switching control signal at a timing corresponding to the zero-cross point.

Abstract: A device is provided for controlling an illumination device (50), including a control circuit (110) having an input (102) for coupling to a network voltage conductor (30) and an output (104) for coupling to a supply voltage conductor (40) of the illumination device (50). The control circuit (110) is designed to supply a supply voltage and control signals modulated onto the supply voltage to the illumination device (50) via the output (104). A button (120) influences the generation of the control signals. The control circuit (110) produces an internal supply voltage (Vint) from a voltage which reduces between the input (102) and the output (104) of the control circuit. In the non-actuated state, the button (120) bypasses the input (102) and the output (104) of the control circuit (110).

Abstract: An output power protection apparatus includes a DC conversion unit, an output protection unit, a high-voltage battery, a low-voltage battery, and a control unit. The DC conversion unit converts an input DC power into an output DC power. The output protection unit is connected in series to the DC conversion unit, and the output protection unit has a plurality of protection circuits connected in parallel to each other. When a short-circuit condition occurs between the high-voltage battery and the low-voltage battery or the low-voltage battery is reversely connected in polarity, the control unit generates a control signal to control the protection circuits to disconnect the connection between the low-voltage battery and a low-voltage device, and the DC conversion unit.

Abstract: An integrated drive circuit for multi-segment electroluminescent displays is provided. During a charging phase, the electroluminescent segments are charged by a common charge circuit, and partially discharged using separate discharge circuits associated with individual electroluminescent segments. A controller provides essentially independent control over the respective discharge circuits so, by the end of the charging phase, the EL segments can be charged to correspondingly different final voltages. Then during a discharging phase following the charging phase, the electroluminescent segments are completely discharged, thereby emitting an intensity of light that varies roughly in proportion to the final accumulated voltage. The controller can be pre-programmed with a spatial-temporal light pattern so that, using the disclosed integrated drive circuit, the electroluminescent display can be operated to generate rudimentary animations.

Abstract: A synchronous rectifier control circuit an includes a current transformer (CT), a bridge rectifier, and a comparator, where the CT is connected in series to a secondary side, performs sampling on a loop current of the secondary side to obtain a current detection signal, and outputs the obtained current detection signal to the bridge rectifier; the bridge rectifier acquires a secondary-side sampling current according to the current detection signal, and outputs the secondary-side sampling current to the comparator so that the comparator generates a voltage difference; and an output signal of the comparator turns over so as to control on and off of a synchronous rectifier transistor. In this way, high-speed and high-precision control over a synchronous rectifier transistor can be implemented. The control is simple and is low in cost.

Abstract: A projector that outputs a first image and a second image alternately, includes: a discharge lamp driving section that supplies, to a discharge lamp, a drive current that drives the discharge lamp; a state detecting section that detects a deteriorating state of the discharge lamp; and a control section that controls the discharge lamp driving section, wherein the control section controls the discharge lamp driving section so that the absolute value of the drive current becomes relatively small in the first period and relatively large in the second period and, in the second period, the control section controls the discharge lamp driving section so that the discharge lamp driving section supplies an alternating current to the discharge lamp as the drive current and controls the discharge lamp driving section so that at least part of the frequency of the drive current is decreased with the progress of the deteriorating state.

Abstract: A power relay assembly driving apparatus includes a relay unit which switches a connection between a terminal of a battery unit and a terminal of an inverter unit, a switching unit connected in parallel to the relay unit between the terminal of the battery unit and the terminal of the inverter unit, and a battery management system (BMS) which controls the switching unit upon a power cutoff of the battery unit in order to form an equipotential between the relay unit and the terminal of the inverter unit, and controls the relay unit in order to electrically separate the terminal of the battery unit and the terminal of the inverter unit from each other.

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 configurations of an electronic ballast are provided in the present invention. The proposed electronic ballast includes a filter circuit having a first and a second output terminals, a rectifier circuit having a first input terminal, a second input terminal coupled to the second output terminal of the filter circuit, and a first output terminal, and a continuous-conduction-mode charge pump PFC circuit including a first inductor having a first terminal coupled to the first input terminal and a second terminal coupled to the first output terminal of the filter circuit, a second inductor having a first terminal and a first capacitor having a first terminal coupled to the first terminal of the first inductor and a second terminal coupled to the first terminal of the second inductor.

Abstract: An electronic dimming ballast or light emitting diode (LED) driver for driving a gas discharge lamp or LED lamp may be operable to control the lamp to avoid flickering and flashing of the lamp during low temperature or low mercury conditions. Such a ballast or driver may include a control circuit that is operable to adjust the intensity of the lamp. Adjusting the intensity of the lamp may include decreasing the intensity of the lamp. The control circuit may be operable to stop adjustment of the intensity of the lamp if a magnitude of the lamp voltage across the lamp is greater than an upper threshold, and subsequently begin to adjust the intensity of the lamp when the lamp voltage across the lamp is less than a lower threshold. Subsequently beginning to adjust the intensity of the lamp may include subsequently decreasing the intensity of the lamp.

Abstract: A projector that outputs a first image and a second image alternately, includes a discharge lamp driving section that supplies, to a discharge lamp, a drive current that drives the discharge lamp; a state detecting section that detects a deteriorating state of the discharge lamp; and a control section that controls the discharge lamp driving section, wherein the control section controls the discharge lamp driving section so that the absolute value of the drive current becomes relatively small in the first period and relatively large in the second period and, in the second period, the control section controls the discharge lamp driving section so that the discharge lamp driving section supplies an alternating current to the discharge lamp as the drive current and controls the discharge lamp driving section so that at least part of the frequency of the drive current is decreased with the progress of the deteriorating state.

Abstract: A liquid crystal display (LCD) device's microcontroller is used drive an LCD lamp ballast such that the scrolling effect from its light leakage may be reduced to a visually imperceptible level. A check may be performed of lamp's control status in order to verify the microcontroller's ability to properly and accurately control the lamp ballast. The microcontroller may then determine a frequency and duty cycle to use for the microcontroller's PWM control signal. Thereafter, the microcontroller may generate the PWM control signal in accordance with the determined frequency and duty cycle, and drive the lamp ballast using the control signal.

Abstract: A damper circuit is operable to dampen resonance of an electromagnetic interference filter when a phase dimmer activates. The damper circuit includes a capacitor and a bipolar junction transistor (BJT). The capacitor includes a first terminal and a second terminal. The BJT includes a control terminal, a collector terminal, and an emitter terminal. The control terminal of the BJT receives a control signal to make the BJT operate in the amplified area, and the collector terminal of the BJT is electrically connected to the second terminal of the capacitor. The first terminal of the capacitor receives the resonance generated to by the electromagnetic interference filter, and the BJT and the capacitor cooperate to dampen the resonance generated by the electromagnetic interference filter when the BJT operates in the amplified area.

Abstract: The voltage detection module according to the invention comprises: a first electric terminal; a second ground terminal; a load resistor, connected to the first electric terminal; a main gas-filled spark gap, arranged in series between the load resistor and the second terminal; and a main capacitor, connected, on the one hand, to a first middle point situated between the load resistor and the main gas-filled spark gap and, on the other hand, to the second terminal. The voltage detection module also comprises a light source connected in series between the main gas-filled spark gap and the second terminal, the light source and the main gas-filled spark gap being separate from one another. The voltage detection module comprises an additional stage capable of limiting the voltage applied to the terminals of the gas-filled spark gap to a threshold voltage chosen so as to prevent the gas-filled spark gap from always being on.

Abstract: An electro magnetic ballast (110) for a gas discharge lamp (2) comprises: input terminals (3), for receiving a mains voltage; lamp connector terminals (4), for receiving a lamp; a controllable semiconductor switch (26) coupled in parallel to the lamp connector terminals; a current sensor (127) connected in series with the controllable switch (26); and a control circuit (28) for controlling the controllable switch (26) and responsive to the current sensor (127). When operating in a normal mode, the control circuit (28) is responsive to a current sense signal received from the current sensor to switch the controllable switch (26) ON if said current sense signal indicates a current flowing in the controllable switch (26) and to switch the controllable switch (26) OFF if said current sense signal indicates that no current is flowing in the controllable switch (26).

Abstract: A method and apparatus are provided for protecting a semiconductor device from damage. The method may include the steps of providing an active semiconductor device on a surface of a semiconductor substrate where the active device is surrounded by an inactive semiconductor area, and providing a soft metallic guard element in the inactive semiconductor area around at least a portion of the periphery of the active device wherein the metallic guard element is connected to ground potential and not to the active device.

Abstract: A damper circuit is operable to dampen resonance of an electromagnetic interference filter when a phase dimmer activates. The damper circuit includes a capacitor and a bipolar junction transistor (BJT). The capacitor includes a first terminal and a second terminal. The BJT includes a control terminal, a collector terminal, and an emitter terminal. The control terminal of the BJT receives a control signal to make the BJT operate in the amplified area, and the collector terminal of the BJT is electrically connected to the second terminal of the capacitor. The first terminal of the capacitor receives the resonance generated to by the electromagnetic interference filter, and the BJT and the capacitor cooperate to dampen the resonance generated by the electromagnetic interference filter when the BJT operates in the amplified area.

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: A discharge lamp lighting circuit includes an open protection circuit. The discharge lamp lighting circuit includes an open protection circuit and an over-voltage detecting circuit. The open protection circuit detects whether any of the discharge lamps are unlit, and sends a voltage control signal to a control circuit if one of the discharge lamps is not lit, whereby the control circuit sends a pulse signal to a buck converter according to the voltage control signal, and the buck converter generates and outputs a DC voltage according to the pulse signal. If the DC voltage from the buck converter reaches a predetermined voltage, the over-voltage detecting circuit conducts and sends a voltage control signal to the control circuit, and the control circuit ceases operating according to the voltage control signal. Consequently, damage to the other normal discharge lamps is prevented.

Abstract: An improved electron multiplier bias network that limits the response of the multiplier when the multiplier is faced with very large input signals, but then permits the multiplier to recover quickly following the large input signal.

Abstract: The invention relates to a lamp base comprising an electronic component with a mounting plate (20) and electronic SMD components (10) fixed thereon. The mounting plate (20) has bent sections (201-205), so that the surface (20a) intended for mounting the electronic components (10) has areas (201a-205a) located on different planes. The mounting plate (20) is preferably curved in a meandering fashion to allow a compact spatial placement of the electronic component (10).

Abstract: An inverter is powered from a DC voltage whose instantaneous absolute magnitude is equal to that of the AC power line voltage except for being prevented from falling below a level equal to half the peak of the power line voltage. The inverter's output is loaded via a series-tuned high-Q LC circuit. Two fluorescent lamps are loading the secondary winding of a transformer whose primary winding is connected across the capacitor of the LC circuit. The magnitude of the voltage present across the capacitor is normally limited by the loading of the fluorescent lamps. However, with the lamps removed, if not expressly prevented from doing so, the magnitude of the voltage across the capacitor will increase to a destructive level due to Q-multiplication.

Abstract: An input circuit for a dimming circuit control unit having a single input signal protocol includes a first input line to receive a first input voltage signal and a second input line to receive a second input voltage signal. A first voltage divider is electrically connected to the first input line to receive the first input voltage signal and to divide the first voltage of the first input voltage signal. A second voltage divider is electrically connected to the second input line to receive the second input voltage signal and to divide a second voltage of the second input voltage signal. An inverter is connected to the first voltage divider to invert the first input voltage signal. An analog to digital converter is electrically connected to the first voltage divider to convert the first voltage when the first input signal is analog such that the dimming circuit control unit always receives a digital signal having the single input protocol.

Abstract: A ballast circuit for a plurality of serially connected, high pressure gas discharge lamps comprises an electromagnetic ballast arrangement receptive of an input power signal, providing an output ballast voltage for driving the plurality of lamps, and providing an open circuit ballast voltage when the lamps are disconnected from the arrangement. A first ignitor circuit is connected between the ballast arrangement and the first lamp, and produces at least one ignitor pulse of high voltage and high frequency compared to the open circuit ballast voltage, to initiate starting of the first lamp. A second ignitor circuit is connected between the first lamp and a second lamp so as to be supplied with current through the first lamp. The second circuit produces at least one ignitor pulse of high voltage and high frequency compared to the open circuit ballast voltage after the first lamp begins to start and drops substantially in impedance, to initiate starting of the second lamp.

Abstract: A capacitor network includes a plurality of capacitors in series. Each capacitor has a preselected capacitance and breakdown voltage. The sum of the breakdown voltages of all the capacitors is at least equal to a desired voltage value. The capacitances of the capacitors are chosen to provide a desired capacitance value when connected in series. At least one capacitor has a break-down voltage equal to greater than fifty percent of the desired voltage value and a capacitance approximately equal to the desired capacitance value.

Abstract: A circuit arrangement for supplying a discharge lamp comprises a control circuit which is provided with an integrated circuit. Means for generating a signal which is a measure of the lamp voltage are coupled to one pin of the integrated circuit. The periodic switching of the integrated circuit between a first and a second state insures that the lamp voltage will not exceed a minimum admissible value and a maximum admissible value. The use of only one pin makes the integrated circuit simple and accordingly inexpensive, while in addition only a small number of external components is required.

Abstract: An electroluminescent lamp is driven by a driving circuit that can supply an approximately sinusoidal signal, a bi-directional sawtooth signal or a single-ended sawtooth signal. Switches selectively transfer energy from a battery to an inductor and then from the inductor to the lamp. In one embodiment, the lamp voltage is compared to a reference waveform, such as a sinusoid. The switches are activated responsive to the error between the lamp voltage and reference waveform to minimize the error. The lamp can thus be driven with a closer approximation of the reference waveform.

Abstract: A gas discharge lamp electronic ballast circuit including a gas discharge lamp (51); a rectifier circuit (11a, 11b, 11c, 11d, 13) responsive to AC power for providing a full wave rectified sinewave voltage across output terminals of the rectifier circuit; a transformer (T1) having a primary winding and a secondary winding; a switching circuit (29) for repetitively connecting the rectifying circuit full wave rectified sinewave voltage to the primary winding; a driving circuit (33, 35, 37, T2, 49) responsive to the secondary winding for driving the lamp with a sinusoidal voltage having a predetermined frequency; a current sensing circuit (39, 41, 45, 47, 43) for sensing an average of peaks of current flowing in the driving circuit; and a pulse width modulation circuit (25) responsive to the full wave rectified sinewave voltage and the current sensing means for pulse width modulating the switching circuit at the predetermined frequency such that the rectifier circuit provides a current having a flattened full wa

Abstract: A clocked power supply is proposed which contains a fault current detection means (32) which evaluates a voltage drop occurring at an ohmic measuring resistor (25), and emits a switch-off signal (40) to a clocked voltage converter (5). The ohmic measuring resistor (25) is arranged in a line (24) of the clocked voltage converter (5) in which the alternating operating current of the clocked voltage converter (5) flows, the frequency of which alternating operating current is equal to the frequency of a switching signal (23) with which a circuit breaker (16) is operated. In order to suppress the portion of the voltage drop which can be tapped at the ohmic measuring resistor (25) and whose frequency corresponds to that of the switching signal (23), means, for example a low pass filter (33) and/or a parallel capacitor (26) which bridges the ohmic measuring resistor (25) are provided.

Abstract: A new fluorescent device including an electronic fluorescent starter, a phase leading capacitor, a ballast, a bridge rectifier, a fluorescent lamp, a brightness compensation circuit, and a control circuit, the electronic fluorescent starter consisting of a master switch circuit, an ignition circuit and a time control circuit, wherein the electronic fluorescent starter matches with the ballast to turn on the fluorescent lamp; the control circuit turns the electronic fluorescent starter to the open circuit state when the fluorescent lamp is turned on; the brightness compensation circuit improves the intensity of light from the fluorescent lamp.

Abstract: A current supplied to a discharge lamp (100) is an A.C. current having a predetermined frequency from an inverter circuit (70), and its power control is carried out by changing the current setting (setting signal) of a chopper circuit (40) constituting a constant current circuit. When a value is set by an output luminance regulator (120), this set current value is inputted to a chopper control circuit (130). The chopper control circuit (130) checks the current detected by a current detector (110) and outputs a current control to a gate terminal (41) of the chopper circuit (40) so that the output current may coincide with the set current value. Accordingly, the power supplied from the inverter circuit (70) to the discharge lamp (100) is controlled by the chopper circuit (40).

Abstract: A key touch dimmer includes a switching device through which AC line current is passed to brighten a lamp in response to a control signal generated by a microprocessor. The microprocessor receives an input indicative of the zero crossing points of the AC line current and synchronizes this input with its own internal clock circuitry to generate a firing signal for the switching device at the correct phase angle in the next half cycle of the AC line current. The dimmer has memory capability whereby the lamp, when turned back on, will brighten to a preset level. This brightening is accomplished in a gradual manner. Likewise, a turned off lamp will fade to zero brightness, with the dimmer retaining the preset brightness level. The microprocessor shuts down quickly in the event of a power outage to preserve memory. An optional display includes a plurality of LEDs for indicating light level. Other options include providing the dimmer with several keys, each of which can be adjusted to a respective preset level.

Abstract: A circuit arrangement for preheating electrodes of a discharge lamp connected in series with a ballast by means of a supply voltage of alternating polarity. The circuit arrangement is provided with a switching element (S) which shunts the lamp and which is operated by means of a control signal. A circuit portion (II) adjusts both the phase and the frequency of the control signal in dependence on whether the ballast is inductive or capacitive. The electrodes of the lamp are preheated in a short period both for an inductive ballast and for a capacitive ballast.

Abstract: Power saving circuitry is provided for use with fluorescent lights, inductive loads and resistive loads. The circuitry comprises a power circuit connectable to an alternating circuit power supply and a control circuit. The power circuit includes a bilateral switch, and the control circuit includes means for timing the operation of the bilateral switch so that the switch conducts current for a predetermined time during each half-cycle of the power supply which terminates at a predetermined interval before the end of each half cycle. A preferred embodiment of the power saving circuitry, adapted for use with fluorescent lights or inductive loads such as electrical motors, also comprises a Back-EMF suppressor circuit. The bilateral switches are preferably made up of one or more unilateral switch devices such as field effect transistors. The subject circuitry reduces power consumption while at the same time providing for a power factor correction.

Abstract: A powder puff has a polyester pile fabric for applying cosmetics or the like to the skin.

Abstract: A starting circuit is used in combination with a high intensity discharge lamp having electrodes. An inductor is in series with the electrodes of the lamp, and a first switching transistor is arranged in series with a diode and a load resistor. The first switching transistor, diode, and resistor are arranged in shunt with the electrodes of the lamp and in series with the inductor for charging the inductor when the first switching transistor is switched ON. The energy stored in the inductor is discharged as a voltage pulse across the lamp when the first switching transistor is switched OFF. A first bias circuit turns the first switching transistor ON at a first voltage level from an AC power source. A second switching transistor turns the first transistor OFF at a second voltage level. A second bias circuit turns the second switching transistor ON at the second voltage.

Abstract: An electronic ballast for use with a fluorescent lamp. A pair of oppositely poled diodes connected in parallel with a transformer used to drive the switching transistors of an inverter in the ballast, ensuring operation of the transistors at zero current crossing.

Abstract: A discharge lamp lighting apparatus comprises a transformer for stepping up an AC power source voltage from an AC power source to produce a high voltage as an output voltage required for lighting a discharge lamp. Particularly, the lighting apparatus further comprises a diode for rectifying the output voltage of the transformer to be supplied to the discharge lamp. The amount of current supply from the AC power source is determined to obtain an output impedance capable of limiting the current which is to flow through the discharge lamp after the start of discharging to maintain the voltage across the discharge lamp at a level required for continuing the discharge.

Abstract: A two-terminal, alternating current power control device connected in an electrical path between a load and a remote switch, comprising a current switching device, a controlling device and a direct current power supply device. The current switching device provides a low impedance electrical path in response to the application of triggering signals thereto, and provides a high impedance electrical path in the absence of the triggering signals. A control circuit is provided for applying triggering signals to the current switching device as the proper time in the AC cycle, and is responsive to a momentary interruption in the applied AC voltage so as to effect change in the power intensity or timed duration of power delivered to the load. A remote switch in the electrical path can be the source of a momentary power interruption.