Abstract: High-frequency transformers using solid wire for welding-type power supplies are disclosed. An example welding-type power supply transformer includes: a first coil assembly comprising a first plurality of turns of a first solid wire wrapped around a first bobbin to form a first single-layer primary winding, and a second plurality of turns of a second conductor over the first plurality of turns to form a first single-layer secondary winding; a second coil assembly comprising a third plurality of turns of a second solid wire wrapped around a second bobbin to form a second single-layer primary winding, and a fourth plurality of turns of the second conductor over the third plurality of turns to form a second single-layer secondary winding; and first and second cores disposed at least partially within the first and second bobbins.

Abstract: An LED drive method drives an LED by a drive current. The LED drive method uses a voltage conversion unit, which includes a coil and a first switch, and converts an external voltage into a first voltage, which is a DC voltage, by controlling the first switch to be on in an on-pulse period of a first drive signal. A constant current drive unit is provided with the first voltage and generates a drive current based on a second drive signal.

Abstract: If a dimming ratio of a light source unit is higher than a first ratio, an ON width of a first switching device is increased with a second switching device kept off when the dimming ratio is increased, and also the ON width of the first switching device is decreased with the second switching device kept off when the dimming ratio is decreased. If a dimming ratio of the light source unit is lower than the first ratio, the ON width of the second switching device is regulated with the ON width of the first switching device held at a lower limit.

Abstract: An LED driver includes a transformer, current control loop and current adjustment circuit. The primary side of the transformer transfers energy to the secondary side of the transformer responsive to an input signal. The secondary side delivers output current to one or more LEDs at a magnitude corresponding to the amount of energy transferred to the secondary side. The current control loop controls current in the primary side so that the output current equals a reference current signal. The current adjustment circuit injects a current adjustment signal into the current control loop responsive to a phase-cut signal which removes a portion of the input signal. The current control loop also decreases the current in the primary side responsive to the current adjustment signal so that a brightness of each LED connected to the secondary side is decreased by an amount corresponding to the magnitude of the current adjustment signal.

Abstract: An LED driver has a power supply configured to receive power from a power input. A primary controller configured to receive power from the power supply and output power to a power output. The power output is configured to be connected to LED lights. A dimmer provides a dimming signal, and the dimmer has an adjustable voltage circuit. An offset voltage is added to a ground path on the adjustable voltage circuit. The offset voltage can be created by a silicon diode adding the offset voltage to a transformer's secondary winding ground path on a DC regulated voltage circuit. The adjustable voltage circuit can be formed as the DC regulated voltage circuit. The DC regulated voltage circuit is a 10 VDC regulated voltage circuit.

Abstract: The present invention relates to a multi-output self-balancing power circuit. In one embodiment, a multi-output self-balancing power circuit can include: a transformer formed by a primary winding and n (e.g., greater than 2) series connected secondary windings; n output circuits corresponding to the n secondary windings, where each of the n output circuits can include a rectifier diode and a filter capacitor, and a load can be parallel coupled with the filter capacitor; n output circuits series coupled between a first output terminal of a first secondary winding and a second output terminal of an nth secondary winding; and (n?1) current balancing capacitors coupled between a common junction of n secondary windings and a common junction of n output circuits.

Abstract: A semiconductor light emitting element drive device includes: a converter circuit configured to supply a light source unit with a load current from a first-primary winding; and a current regulation circuit. The converter circuit further includes a second-secondary winding. The current regulation circuit includes a switching device (second switching device) connected in series with the second-secondary winding. In a dimming ratio of the light source unit is lower than a first ratio, the second switching device is controlled to ON and OFF so as to decrease the load current through the light source unit by a shunt of a part of the energy stored in the primary winding.

Abstract: A multi-lamp driving system includes a power supply and at least one balance transformer. Each balance transformer includes two cores, two primary windings, two secondary windings and two protection windings. Each primary winding is wrapped around a core and serially connected to a lamp to form a first circuit branch in parallel connection with each other. The first circuit branches are powered by the power supply. The Each secondary winding is wrapped around a core and connected to a primary winding. The two secondary windings are connected in series to form a short circuit loop. Each of the protection windings is wrapped around a core and connected to a primary winding. The protection windings are wrapped in opposite directions and connected in series to form a second circuit branch. The second circuit branch outputs voltage signals to the power supply when induced voltages crossing the protection windings are unequal.

Abstract: Disclosed is a liquid crystal display (LCD) backlight inverter. The LCD backlight inverter includes a lamp open detection unit outputting a first open detection voltage for a preset time period when it is determined that a predetermined lamp is open, based on a current voltage corresponding to the current of the predetermined lamp of a plurality of lamps, a first open determination unit outputting an open detection signal when the first open detection voltage is input, a second open determination unit outputting a protection signal when it is determined that all of the plurality of lamps are open based on detection voltages of the plurality of lamps, a temporary protection determination unit outputting a frequency change signal when both the open detection signal and the protection signal are input, and an operating frequency control unit changing an operating frequency to a preset protective frequency according to the frequency change.

Abstract: A secondary side post regulator arrangement for a plurality of LED strings. For each secondary winding, a first electronically controlled switch is provided arranged to control the power output, and a LED string is connected thereto. A second electronically controlled switch is further connected in series with the LED string, arranged to receive a PWM signal, thereby pulsing current through the LED string. A current sensing element is further provided outputting a voltage representation of the current through the LED string, and a synchronized sampling circuit is provided arranged to sample the voltage representation during the on period of the second electronically controlled switch. The sampled and held voltage representation is compared with a reference signal and fed back to control the first electronically controlled switch. The voltage output associated with each secondary winding is controlled, responsive to the reference voltage.

Abstract: A transformer arranged to be used for an illuminating apparatus includes a closed-magnetic-circuit core, a primary coil wounded around the closed-magnetic-circuit core, and multiple secondary coils wounded around the closed-magnetic-circuit core. The secondary coils include first ends and second ends. The illuminating apparatus includes multiple discharge lamps. Each of the first ends and each of the second ends of each secondary coil are connected to different discharge lamps.

Abstract: The present invention provides a transformer apparatus configured by integrating an inverter transformer and balance transformer to be a downsized form, and a drive circuit using the transformer apparatus. The transformer apparatus comprises an inverter transformer having a core potion on which a primary coil and a secondary coil are wound, and a balance transformer having a core portion on which a primary coil and a secondary coil are wound, wherein the inverter transformer and the balance transformer are integrally formed by sharing a part of the core portions.

Abstract: Disclosed is a liquid crystal display (LCD) backlight inverter. The LCD backlight inverter includes a lamp open detection unit outputting a first open detection voltage for a preset time period when it is determined that a predetermined lamp is open, based on a current voltage corresponding to the current of the predetermined lamp of a plurality of lamps, a first open determination unit outputting an open detection signal when the first open detection voltage is input, a second open determination unit outputting a protection signal when it is determined that all of the plurality of lamps are open based on detection voltages of the plurality of lamps, a temporary protection determination unit outputting a frequency change signal when both the open detection signal and the protection signal are input, and an operating frequency control unit changing an operating frequency to a preset protective frequency according to the frequency change.

Abstract: For having magnitudes of all currents for supplying for all passive elements in a same product be equal, a current balancing module, which has balancing transformers as more as approximately half an amount of all the passive elements, is provided for meeting such requirements. The provided current balancing module is for solving defects caused by complicated designs and increased volumes caused by an increased number of balancing transformers. Each current path in the current balancing module flows through two mutual-corresponding passive elements and at least one balancing transformer. All the current paths have a same magnitude in current with the aid of a pair of sinusoidal waves having same magnitudes and opposite poles, and the aid of all the balancing transformers having a same number of turns.

Abstract: A lighting circuit includes a capacitor and inductor for a resonance, and a first output, a second output, a resistor and a monitor circuit. A DC-AC converting circuit generates an AC voltage from a DC voltage. The resistor has an end connected to the second output and the other end connected to an end of a secondary winding. A monitoring output is connected to the other end of the resistor, and is provided for providing a signal for monitoring a current flowing to a discharge lamp. The end of the resistor is connected to a grounding conductor GND. The monitor circuit receives a signal from the monitoring output. The monitor circuit generates a signal for monitoring a current IL flowing to the discharge lamp.

Abstract: The invention provides a balance transformer and a backlight apparatus using the same. The balance transformer comprises a first main coil, a second main coil, a first induction coil, and a conductor. The first main coil has a first contact point and a second contact point, and the second main coil has a third contact point and a fourth contact point. The first induction coil is corresponding to the first main coil and the second main coil. The conductor is then series connected to the first contact point and the fourth contact point. Accordingly, the balance transformer drives the backlight apparatus to light and balances the currents of a plurality of light units of the backlight apparatus.

Abstract: A backlight assembly includes a light-generating unit and an inverter. The light-generating unit includes a first U-shaped lamp and a second U-shaped lamp parallel with each other. Electrodes of the first and second U-shaped lamps are disposed at one side of the light-generating unit. The inverter includes a multi-output transformer, a first output terminal and a second output terminal. The multi-output transformer generates a first driving voltage and a second driving voltage having a phase opposite to a phase of the first driving voltage. The first and second output terminals electrically connect the first and second U-shaped lamps with the multi-output transformer. The multi-output transformer applies the first and second driving voltages to the first and second U-shaped lamps via the first and second output terminals.

Abstract: A transformer arranged to be used for an illuminating apparatus includes a closed-magnetic-circuit core, a primary coil wounded around the closed-magnetic-circuit core, and plural secondary coils wounded around the closed-magnetic-circuit core. The plural secondary coils includ respective first ends and respective second ends. The illuminating apparatus includes plural discharge lamps. Each of the respective first ends and each of the respective second ends are arranged to be connected to discharge lamps, out of the plurality of discharge lamps, different from each other. This transformer prevents variation of lighting timings of discharge lamps, accordingly providing an illuminating apparatus and a display apparatus having little brightness variation.

Abstract: A backlight inverter includes a transformer boosting an input voltage at a ratio of a primary winding to a secondary winding of the transformer and outputting a first voltage and a second voltage; a protection level signal generator causing a phase delay between the first voltage and the second voltage, and generating a protection level signal, the protection level signal being a sum of the phase reversed first voltage and the second voltage; and an arc state detector comparing the protection level signal with a reference voltage and generating a detection signal; and a diving controller maintaining or stopping a supplying of an input voltage to the transformer in response to the detection signal, wherein in addition to the phase delay, another phase delay is caused by an open circuit in the transformer, so that a maximum value of the protection level signal is larger than the reference voltage and the input voltage is stopped.

Abstract: The field of the invention is mainly that of light boxes used for the illumination of display screens using optical valves, notably for liquid crystal matrix displays also known as LCD screens. The light sources used are generally fluorescent tubes powered with a high voltage by devices comprising Royer electronic oscillators. These electronic oscillators do not allow wide dynamic ranges of luminance, which can be necessary for certain applications, to be easily attained. The oscillator according to the invention comprises an electronic device for discharging the stored electrical energy, said discharge device being controlled by an electronic control device using chopping modulation, thus enabling wide dynamic ranges of luminance to be attained.

Abstract: This invention aims to decrease the leakage current of a dielectric barrier discharge lamp, and to prevent generation of the luminance slope between both electrodes. Electrodes 3 and 4 are formed in the outer surface of the dielectric barrier discharge lamp 1, and the high voltage side of the high frequency power sources 5 and 6 is connected to the electrodes 3 and 4, respectively. The low voltage side of the high frequency power sources 5 and 6 is connected to the grounding voltage GND. The output voltage waveform of the high frequency power sources 5 and 6 have different phases each other and inverted polarities each other.

Abstract: There is provided an ignition coil alleviating an insulating load between output terminals and at inside of the ignition coil and stabilizing insulating performance by constituting two outputs from the ignition coil by the same output electrode. Specifically, the invention is characterized in arranging two ignition plugs at a single cylinder, providing a center tap terminal at a secondary coil, regularly winding the secondary coil until reaching the center tap terminal and inversely winding the secondary coil from a regular winding direction to an inverse winding direction after reaching the center tap.

Abstract: A fluorescent lamp electronic ballast for use with fluorescent lamps of the preheat or heated filament type is provided. The electronic ballast includes a multiple output DC to DC converter with a primary winding and a plurality of secondary windings for connecting to a plurality of lamp filaments. Each secondary winding is connected to a lamp filament through a diode/capacitor combination with a current transformer primary located in a high frequency loop. A sensing circuit is connected to a current transformer secondary. A controller is connected to the sensing circuit and controls the filament power supply. Advantages include the ability to predict lamp end of life, detect disconnected filaments and other problems that appear as an open circuit such as loose or misinstalled lamps and prevent arcing, detect smoldering of a heavily carbonized lamp holder, or detect short circuits.

Abstract: An electromagnetic ballast for sequentially starting and simultaneously operating first and second gaseous discharge lamps includes a transformer having a magnetic core, a primary winding for connection to an AC voltage source and first and second secondary windings, all wound around the core. The first and second secondary windings are wound in opposite directions to produce voltages in opposition to each other. The ballast includes first and second series circuits, each including one of the lamps. The magnetic core has an elongated slot formed under the second secondary winding. The slot width relative to the core width, and to the slot length, are dimensioned to provide improved operating performance.

Abstract: An illumination unit comprises a high-frequency supply (1) and a low-pressure discharge lamp (2). The high-frequency supply (1) is provided with a first and a second output (13a, 13b). The outputs each deliver a HF-varying voltage with respect to ground. The voltages have the same magnitude and are in phase opposition. The supply (1) is provided with a further output (13c) which is substantially free of high-frequency voltage variations with respect to ground. The low-pressure discharge lamp (2) is provided with a tubular discharge vessel (20) with an ionizable filling.

Abstract: A power supply device for a gas filled arc-type lamp having a transformer with a core with a primary coil and a secondary coil, a power source coupled to the primary coil of the transformer core and providing a generally sinusoidal signal, a connector for joining the secondary coil of the transformer to the gas-filled arch-type lamp, and an unbalanced capacitance for introducing even-order harmonic distortion on the generally sinusoidal signal on the primary coil of the transformer and generating a generally sinusoidal signal on the secondary coil of the transformer such that a flow of ionized gas is created within the gas-filled arch-type lamp for dispersing any bubbles and standing waves in the lamp and so as to avoid adjustment of the power supply. The distorted signal has one-half cycle longer with a lower peak voltage than the other half-cycle.

Abstract: A low cost power supply with enhanced safety protection for neon lamps connected in a midpoint commoned lamp configuration. The power supply has a return path which is isolated from the earth ground so that a fault current does not flow from the output terminals to the earth ground. The windings are phased in a series opposing configuration such that the voltages between the output terminals sum to zero. This power supply of mid-point connected secondary coil design is capable of operating lamp lengths that typically require 15,000 volts of open circuit voltage while not exceeding 7500 volts to ground when any one output terminal is grounded.

Abstract: A fluorescent lamp ignition circuit of the type including a DC voltage stabilizer to process input voltage into a constant voltage by dropping or boosting, an inductance filter to receive output power supply from the DC voltage stabilizer and to remove surge from it, an oscillator having a transformer, which receives output power supply from the inductance filter and then provides a sin-wave output for igniting a fluorescent lamp, and a feedback circuit connected between the oscillator and the fluorescent lamp to provide a feedback signal to the DC voltage stabilizer, wherein the feedback circuit includes two shunt resistors, which connect the mid-point of the secondary side of the transformer of the oscillator to earth, and two diodes respectively connected between the shunt resistors and the DC voltage stabilizer to form a double-feedback loop.

Abstract: A dimming control circuit provides power from an ac source to a compact fluorescent lamp. The circuit generally includes a resonant half-bridge inverter driven by a pulse-duration-modulated voltage, for providing a high-frequency ac voltage between the lamp electrodes. A combination inductive and capacitive snubber circuit reduces switching losses in the inverter and increases the efficiency of the dimming circuit. A low-voltage transformer connected across the resonant portion of the inverter provides voltage to heat the lamp filaments. The filament voltage is substantially constant over a range of pulse-durations providing a dimming range from about 100% to 1% of full light output. A power supply circuit having a power factor of about 0.95 provides both high-voltage and low-voltage dc power to the dimming circuit with minimal losses. A shutdown circuit is provided to shut off power to the lamp if the dimming circuit is miswired or a ground fault occurs.

Abstract: A power circuit for N series connected loads according to the present invention includes N transformers having primary windings connected in series across a constant current AC source and secondary windings connected in series with the N loads. N-1 conductors are coupled from a junction between the loads to a corresponding junction between the secondary windings. Failure of one of the loads resulting in an open circuit will not interrupt power to the remaining loads.

Abstract: A current-balancing transformer is provided to supply plural parallel-connected electrical loads, especially loads such as gas discharge lamps which exhibit negative impedance and/or non-linear impedance over at least a part of their normal operating range. The current-balancing transformer forces current sharing among the loads so that each of the parallel-connected loads is supplied operating current.

Abstract: An electronic ballast-inverter circuit for powering one or more fluorescent lamps or the like includes two identical circuits operating at different DC offsets, each circuit including a tank circuit composed of a primary winding of the power transformer and a capacitor such that each tank circuit resonates at the same frequency, and including a switching transistor connected to each tank circuit. These two transistors are operative on alternate half cycles of the sine wave generated by the inverter, so as to obtain the push-pull operation needed by the inverter. Each circuit includes a base drive current source for each transistor that is controlled by the polarity of an additional primary winding of the power transformer. For improved efficiency, the circuit is designed to be operable from an unsmoothed DC voltage source.

Abstract: A distributorless ignition system of an internal combustion engine has a supplementary spark energy module to increase spark energy. Two ignition coils each have secondary coils with split secondary center taps. Each of the primary windings is coupled to its own ignition module. The supplementary spark energy module is coupled to each of the split secondary center taps. A pair of spark plugs is coupled to one of the secondary windings and another pair of spark plugs is coupled to the other secondary winding.

Abstract: A lighting system comprises gaseous discharge lamps (8) connected to a source (1) of regulated alternating current through current transformers (5). The primary windings (6) of the current transformers (5) are connected in series to the source (1). The gaseous discharge lamps (8) are connected to the secondary windings (7) of the transformers (5).The lighting system is designed for lighting industrial buildings, streets, highways, stadiums, mines, etc.

Abstract: An energy-saving instant-start series-sequence fluorescent lamp system includes power-reducing capacitor means connected in series circuit arrangement with one or both lamps in a two-lamp system. A protective device is connected in circuit with a first lamp of the system so that in the event the second lamp fails to operate and causes a high current to flow through the first lamp, the protective device reacts to prevent the system from being damaged. A lamp incorporating the power-reducing capacitor and protective device is also disclosed.

Abstract: An electronic ballast circuit for a multiple gaseous lamp load includes a feedback rectifier circuit coupled to a high frequency inverter circuit and to a DC source. The high frequency inverter circuit is also coupled to the multiple gaseous load and a variation in an alterable impedance of the feedback rectifier circuit causes a variation in power applied to the multiple gaseous load and power provided by the DC source.

Abstract: Electrical lamp ballast system for starting and operating fluorescent lamps with improved efficiency. System includes high leakage reactance autotransformer having primary and secondary windings, and a ballast capacitor connected in series with the secondary winding and two serially connected fluorescent lamps of low starting and operating voltage, the secondary circuit being connected to a tap on the primary winding for reducing the ratio of the ballast power input to the lamp light output. The system provides for reduced lamp current crest factor, thereby improving life and operating characteristics of the lamps.

Abstract: High efficiency push-pull inverters minimize undesirable energy losses usually resulting from simultaneous conduction and imperfect switching of the transistor switching means. In each of the disclosed circuits, a saturable inductor and a diode are connected in parallel and across the base-emitter junction of each transistor. Voltage on the base of each transistor causes its associated saturable inductor to saturate, and the saturated inductor then terminates the flow of base current and provides a path for rapid evacuation of the charge carriers stored in the transistor base-emitter junction in order to render the transistor rapidly non-conductive. Each diode provides a drain path for current continuing to flow through its associated saturable inductor after junction evacuation. A novel triggering means initiates oscillation of the inverters.

Abstract: A system for operating gas discharge lamps at high frequency from a high voltage supply, typically 115 V AC with a 160 watt, 25,000 Hz output. The system provides efficient conversion, having the capability of driving any number of lamps up to maximum wattage, inherent open-cirucit and short circuit protection, and higher efficacy from the lamps. Filament power may or may not be used. Filament power is not necessary under conditions when the lamps are forced into a glow discharge to charge each cycle through the use of a tuned resonant circuit. An unsaturated inverter provides fast cut-off times. Dimming capabilities may be provided.

Abstract: A highly efficient, energy saving ballasting and transfer circuit, utilizing a single high frequency inverter ballast unit, capable of powering multiple lamp loads from any direct or alternating electric power source, comprises a current feedback inverter in combination with a leakage transformer, which operates to permit coupling of the single inverter unit to any number of lamps, particularly the gas discharge type. The leakage transformer can power any number of lamps from a single source which, because of its linear transfer function, achieves controlled light output of the lamps proportional to the power input. Thus, an excellent dimming capability is achieved. It is important to note that this leakage transformer is a special case of a certain type of multi-path leakage transformer, where only one secondary coil is used to achieve the same dimming capabilities of multiple secondary embodiments.

Abstract: A highly efficient, energy saving ballasting and transfer circuit, utilizing a single high frequency inverter ballast unit, capable of powering multiple lamp loads from any direct or alternating electric power source, comprises a current feedback inverter in combination with a unique multi-path, independently controlled leakage transformer, which operates to permit coupling of the single inverter unit to any number of lamps, particularly the gas discharge type. The multi-path leakage transformer provides multiple and independent magnetic circuits to power any number of lamps from a single source which, because of its linear transfer function, achieves controlled light output of the lamps proportional to the power input.

Abstract: A circuit arrangement for bicycle lighting systems including a dynamo having an output winding. Front and rear lamps connected in series across the winding. A tap divides the winding into two parts, the lamps each connecting to a corresponding winding part and interconnecting at a junction joint. An impedance is interposed between the tap and lamp junction point. The number of turns and resistances of the winding parts are of value such that the junction point and tap are at the same potential, establishing system equilibrium, under normal operating conditions, despite variation in dynamo voltage and lamp resistance with bicycle speed. The impedance may be provided as the inherent resistance of a further winding connecting the junction point and tap and compensating for a difference in winding part resistance and turns ratios required for equilibrium. A further impedance may be coupled across the rear lamp.

Abstract: The disclosure relates to a ballast unit for gas discharge lamps, particularly fluorescent lamps, by which a substantially constant burning current is supplied to the lamp. The ballast unit includes a transformer mounted on a core having a defined air gap. The transformer is provided with a leakage inductance having a value resulting in a voltage drop of between approximately 15 and 30 percent of an input voltage applied thereto. One or more capacitors are connected in series with the transformer output supply to the lamp. The one or more capacitors provide a capacitance in series with the lamp substantially equal to the ratio of the burning current to the angular frequency of the input voltage multiplied by the secondary no-load voltage supplied to the secondary circuit.

Abstract: High efficiency push-pull inverters minimize undesirable energy losses usually resulting from simultaneous conduction and imperfect switching of the transistor switching means. In each of the disclosed circuits, a saturable inductor and a diode are connected in parallel and across the base-emitter junction of each transistor. Voltage on the base of each transistor causes its associated saturable inductor to saturate, and the saturated inductor then terminates the flow of base current and provides a path for rapid evacuation of the charge carriers stored in the transistor base-emitter junction in order to render the transistor rapidly non-conductive. Each diode provides a drain path for current continuing to flow through its associated saturable inductor after junction evacuation. A novel triggering means initiates oscillation of the inverters.

Abstract: Electrical lamp ballast system for starting and operating fluorescent lamps with improved efficiency. System includes high leakage reactance autotransformer having primary and secondary windings, and a ballast capacitor connected in series with the secondary winding and two serially connected fluorescent lamps of low starting and operating voltage, the secondary circuit being connected to a tap on the primary winding for reducing the ratio of the ballast power input to the lamp light output. The system provides for reduced lamp current crest factor, thereby improving life and operating characteristics of the lamps.