Abstract: Transformers are in a parallel circuit in which a tap changer with a control sensor is associated with each of the transformers and all control sensors are connected together by a communications connection. Each control sensor generates a measurement that is transferred by the communications connection. A measurement is generated with each of the control sensors, and at least one of the measurements of the control sensors of the transformers by the communications connection is transferred to N?1 control sensors. Then a controlling deviation caused by a circuit reactive current is calculated for each control sensor on the basis of the measurements of the control sensors. Finally the tap changer associated with each transformer is actuated by the respective control sensor as a function of the calculated controlling deviation such that minimization of the circuit reactive current is carried out for the respective transformer.

Abstract: A programmed start ballast circuit is presented having a mode control circuit to selectively switch an inverter output load to control operation for cathode preheating, step dimming and/or anti-arcing operation.

Abstract: The present invention relates to a high efficiency LED driver, and driving methods thereof. In one embodiment, a high efficiency LED driving method can include: (i) receiving an AC input voltage to obtain an absolute value thereof; (ii) receiving a DC bus voltage, and driving the LED device through a power switch; (iii) generating a first reference voltage according to a driving current and an expected driving current; (iv) comparing the absolute value against a sum of a driving voltage and the first reference voltage; (v) when the absolute value is greater than the sum of the driving voltage and the first reference voltage, turning off the power switch; and (vi) when the absolute value is greater than the driving voltage but less than the sum of the driving voltage and the first reference voltage, turning on the power switch to generate an output current.

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: A multi-lamp driving system includes a power stage circuit, a pulse width modulation (PWM) controller, a plurality of transformer circuits, and an abnormal detection circuit. Each of the transformer circuits includes a first primary winding and a second primary winding connected in series and a first secondary winding and a second secondary winding respectively outputting AC power signals to drive at least one lamp. The abnormal detection circuit is connected to a junction of the first primary winding and the second primary winding of each of the transformer circuits, and determines if voltages of the junction of the first primary winding and the second primary winding of each of the transformer circuits are different to determine if the at least two lamps are normal. The abnormal detection circuit further generate control signals to control the PWM controller upon the condition that one of the at least two lamps are abnormal.

Abstract: A brightness controller determines a lowest dimmer setpoint and an average power to a light source at the lowest dimmer setpoint. An average power supplied to the light source is set based on a setting of the dimmer relative to the average power at the lowest dimmer setpoint.

Abstract: A backlight unit and a liquid crystal display using the same are provided. The backlight unit includes a plurality of lamps, each including first and second electrodes, first and second substrates, a bottom case for receiving the substrates and lamps, first and second inverter units, and first and second wires. First and second common electrode patterns are formed on the first and second substrates and are commonly connected to the first and second electrodes, respectively. The first and second inverter units are disposed on a rear surface of the bottom case at positions corresponding to the first and second substrates, respectively. The first wire connects the first common electrode pattern and the first inverter unit via holes in the first substrate and the bottom case. The second wire connects the second common electrode pattern and the second inverter unit via holes in the second substrate and the bottom case.

Abstract: Disclosed is an inverter device which is provided with a plurality of transformers and is used for driving a plurality of discharge tube lamps (L1-L6) by using each of the output voltages (VL1-VL6) of the plurality of transformers as voltages to be applied to the plurality of discharge tube lamps (L1-L6), respectively, wherein at least one of the driving frequencies of the plurality of transformers is shifted for each prescribed period of time.

Abstract: Disclosed is an inverter device which is provided with a plurality of transformers and which drives a plurality of discharge tube lamps using the output voltage of the plurality of transformers as applied voltages that are respectively applied to the plurality of discharge tube lamps, wherein at least one axial direction of secondary windings of the plurality of transformers is set in a direction that is different from the other axial directions.

Abstract: An inductive electronic module, comprising a core element having an inner limb (12; 29a) and at least two lateral limbs (14, 16; 33a, 35a; 37a, 39a) associated the inner limb on both sides, the core element being provided with windings (N1, N2, N3, N4) for forming a transformer. A first winding (N1, N2: 47, 49; 51, 53) is implemented as a series connection composed of two partial windings. A first partial winding is formed on a first lateral limb, and a second partial winding is formed on a second lateral limb.

Abstract: A multi-lamp driving circuit for driving a plurality of lamp groups includes an inversion circuit configured to drive the plurality of lamp groups and a current balance circuit electrically connected between the inversion circuit and the plurality of lamp groups. The current balance circuit includes a plurality of transformers, each including a first magnetic loop composed of a first primary winding and a first secondary winding and a second magnetic loop composed of a second primary winding and a second secondary winding. Numbers of turns of the second primary winding and the second secondary winding of each of the plurality of transformers are equivalent, and numbers of turns of the first primary winding and the first secondary winding of each of the plurality of transformers are equivalent.

Abstract: The present invention provides a multiple lamp driving capable of being applied to a multiple lamp system such as an LCD, wherein the multiple lamp driving device includes: a power supply unit for supplying a driving voltage to a lamp unit provided with first to 4nth lamps; and a balancing circuit unit including first to nth balance transformers for receiving the driving voltage from the power supply unit and balancing currents flowing through the first to 4nth lamps, wherein each of the first to nth balance transformers includes a primary side connected to the power supply unit in series and first and second secondary sides electrically connected to the primary side, each one end of the first and second secondary sides is connected to one end of one of the first to 4nth lamps, each of the other ends of the first and second secondary sides is connected to one end of another among the first to 4nth lamps, and the other ends of all of the first to 4nth lamps are connected to a ground.

Abstract: A circuit comprises a power tank, a pair of transformers and multiple loads. The power tank converts a DC input voltage to an AC voltage. The pair of transformers comprise a pair of primary windings and a pair of secondary windings and transform the intermediate AC voltage to an output AC voltage. The pair of primary windings are coupled to the power tank for receiving the intermediate AC voltage, and the pair of secondary windings provide the output AC voltage. The loads are coupled to the pair of secondary windings for receiving the output AC voltage. The pair of secondary windings are serially coupled to each other through the series-coupled loads to achieve current balance among the loads.

Abstract: A lamp driving circuit is provided for controlling individual block luminances provided by corresponding locally dimmed blocks of a backlight unit of an LCD system where the backlight unit employs high voltage discharge lamps that each need to have an AC excitation signal of at least predetermined minimum high voltage level developed there across in order to generate light. The lamp driving circuit includes a plurality of isolation transformers and corresponding low voltage switch circuits. Each isolation transformer has primary windings and a secondary winding. The secondary winding is interposed between a high voltage AC power source and a corresponding one or more lamps. The equivalent circuit impedance of the secondary winding determines what voltage will develop across its respective lamps.

Abstract: The present invention provides a balance circuit including: a first balance trans having a primary coil and a secondary coil, the primary coil being connected to an output terminal of a first lamp, and the secondary coil being connected to an output terminal of a second lamp and having a current controlled by the primary coil; and a second balance trans having a primary coil and a secondary coil, the primary coil being connected to an output terminal of a third lamp, and the secondary coil being connected to an output terminal of a fourth lamp and having a current controlled by the primary coil connected to the output terminal of the third lamp, wherein the secondary coil of the first balance trans is connected to the primary coil of the second balance trans, and an inverter circuit including the same.

Abstract: A fluorescent lamp includes three transformers, a power supply, a converter, and four lamp tubes. The converter converts a direct current (DC) provided by the power supply into an alternating current (AC) generated in a first transformer and a second transformer for driving the four lamp tubes to emit light. The third transformer is connected to the four lamp tubes to balance working electric potentials of the four lamp tubes.

Abstract: There are provided a current balance circuit having a protection function that prevents the current balance circuit from being damaged during a preset time period by maintaining a constant level of power being supplied to the lamp, and a power supply. The current balance circuit having the protection function includes a current balance unit maintaining current balance of lamp driving power supplied to a lamp unit including a plurality of lamps, and a protection unit detecting the lamp driving power supplied to the lamp unit from the current balance unit, cutting-off the lamp driving power after a preset time period when the lamp operates abnormally, and controlling a voltage level of the lamp driving power to a preset reference voltage level or lower during the preset time period.

Abstract: Provided is an inverter circuit capable of suppressing an increase in EMI level. In at least one embodiment, the inverter circuit includes: a drive circuit for outputting a pulse signal; a transformer for outputting a drive signal corresponding to the pulse signal to a fluorescent lamp, the transformer including a secondary winding having one end connected to the fluorescent lamp; a detection control circuit for detecting a detection signal corresponding to the drive signal supplied to the fluorescent lamp; a wiring line connecting another end of the secondary winding of the transformer and the detection control circuit; and a wiring line provided together with the wiring line so that magnetic fields generated are cancelled out each other.

Abstract: A method of driving a lamp of a liquid crystal display device includes generating a control signal; generating a first drive signal using the control signal; generating a second drive signal by shifting a voltage level of the first drive signal; selectively outputting one of a high potential supply voltage and a low potential supply voltage in response to the second drive signal; transforming the selectively outputted voltage; and supplying the transformed voltage to a lamp.

Abstract: The present invention provides a multiple lamp driving capable of being applied to a multiple lamp system such as an LCD, wherein the multiple lamp driving device includes: a power supply unit for supplying a driving voltage to a lamp unit provided with first to 4nth lamps; and a balancing circuit unit including first to nth balance transformers for receiving the driving voltage from the power supply unit and balancing currents flowing through the first to 4nth lamps, wherein each of the first to nth balance transformers includes a primary side connected to the power supply unit in series and first and second secondary sides electrically connected to the primary side, each one end of the first and second secondary sides is connected to one end of one of the first to 4nth lamps, each of the other ends of the first and second secondary sides is connected to one end of another among the first to 4nth lamps, and the other ends of all of the first to 4nth lamps are connected to a ground.

Abstract: A multi-lamp driving circuit includes a power supply, a booster converter including a first winding and a second winding, a plurality of current balance circuits and a plurality of balance converters. The first winding of the booster converter is coupled to the power supply. Each of the current balance circuits includes a plurality of current balance sub-circuits each including a capacitor and a lamp connected in series. One end of each of the current balance sub-circuits is connected to one end of the second winding of the booster converter. A first winding of each of the balance converters is electrically connected between the other end of the second winding of the booster converter and the other end of the current balance sub-circuits of corresponding current balance circuits. Second windings of the balance converters are connected in series.

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: A system for driving a plurality of lamps may monitor the faults of the lamps by detecting the voltage variance of the first, second and third detecting resistors connected to the low voltage ends of the first and second secondary winding for providing the power to the lamps.

Abstract: In a backlight, for example, a pair of U-shaped discharge tubes are connected to connectors of a discharge tube lighting circuit. A secondary output voltage of a first transformer is applied to a first end of one U-shaped discharge tube via a power supply electrode. A secondary output voltage of a second transformer is applied to a first end of the other U-shaped discharge tube via a power supply electrode. A secondary output voltage of a third transformer is applied in common to the other (second) ends of the U-shaped discharge tubes via other power supply electrodes. The secondary output voltages of the first and second transformers are the same in polarity, and are opposite to the secondary output voltage of the third transformer in polarity.

Abstract: Embodiment relate to a lamp driving device and a liquid crystal display device having the same. The embodiments include a plurality of lamps having first and second electrodes, an inverter substrate supplying a high voltage alternating current to at least one of the first and second electrodes of the lamps, a plurality of capacitors connected to the first and second electrodes of the lamps, and a board capacitor connected to at least one of the capacitors.

Abstract: A driving circuit of multi-lamps including a power supply module, a transformer module, a first detection module, and a control module is provided. Whether the power supply module is turned off is controlled by a control signal. The transformer module respectively provides a driving signal and an inverted driving signal to a first terminal and a second terminal of each lamp according to the AC signal. The first detection module detects a first indication signal combined by signals of the first terminal of one lamp and the second terminal of another lamp. The control module generates the control signal according to the first indication signal. Therefore, whether the lamps have a problem of a short circuit or an open circuit, or are in abnormal states can be known from the variations of the first indication signal, and a protection function for the driving circuit can be activated.

Abstract: The present invention provides a protection means for a driving circuit which drives a set of external electrode fluorescent lamps (EEFL). The driving circuit with protection function for driving a set of EEFLs consistent with the present invention includes: a transformer connected to the set of EEFLs; a switching network connected to the transformer which delivers power to the transformer; a sensing circuit connected to the set of EEFLs which detects disconnection if one light source is disconnected; and a controller connected to the switching network which controls the switching network to reduce the total current supplied to the EEFLs which remain connected, if the sensing circuit detects that one EEFL is disconnected. Appropriate protection can therefore be implemented when the EEFL is disconnected on one end or both ends.

Abstract: An inverter includes a pulse width modulation (PWM) circuit, a direct current (DC) voltage input terminal, a storage capacitor, a first transformer, a soft start circuit, and a first transistor. The PWM circuit includes a first output terminal. The first transformer includes a first primary winding. The first primary winding includes a first terminal and a second terminal capable of being grounded via the storage capacitor. The soft start circuit includes an inductor and a first capacitor. A gate electrode of the first transistor is connected to the first output terminal. A source electrode of the first transistor is connected to the first terminal of the first transformer via the inductor. A drain electrode of the first transistor is connected to the DC voltage input terminal and connected to the source electrode via the capacitor.

Abstract: A ring balancer comprising a plurality of balancing transformers facilitates current sharing in a multi-lamp backlight system. The balancing transformers have respective primary windings separately coupled in series with designated lamps and have respective secondary windings coupled together in a closed loop. The secondary windings conduct a common current and the respective primary windings conduct proportional currents to balance currents among the lamps. The ring balancer facilitates automatic lamp striking and the lamps can be advantageously driven by a common voltage source.

Abstract: There is provided a multiple discharge lamp lighting apparatus, which includes an inverter and plurality of inverter transformer. In the multiple discharge lighting apparatus, a discharge lamp is connected to the secondary winding of each inverter transformer, a ballast impedance element is connected in series between a switch of the inverter and the primary winding of each inverter transformer, and a current balancing unit is provided between each two adjacent inverter transformers.

Abstract: A multi-lamp backlight apparatus is disclosed. The multi-lamp backlight apparatus includes 2N lamps, N balancing transformers, and a high-voltage power source. N is a positive integer and k is an integer index ranging from 1 to N. The kth balancing transformer among the N balancing transformers includes a first primary winding, a second primary winding, and a secondary winding. The first primary winding connects in series with the (2k?1)th lamp of the 2N lamps. The second primary winding connects in series with the first primary winding and the (2k)th lamp. The secondary winding corresponds to the first primary winding and the second primary winding. The high-voltage power source is connected between the first primary windings and the second primary windings.

Abstract: A current fed bipolar junction transistor (BJT) based inverter ballast includes base drive circuits configured to drive respective BJT switches, and high-speed drive reverse peak current limiting circuits, configured to operate in conjunction with the respective base drive circuits.

Abstract: A discharge-lamp lighting apparatus includes first and second cold cathode fluorescent lamps (CCFLs) and first and second transformers. The first transformer has a primary winding and a secondary winding. The primary winding receives an AC voltage generated by turning on/off a first switching element pair that is connected to a first DC power source. The second transformer has a primary winding, a first secondary winding, and a second secondary winding. The primary winding of the second transformer receives an AC voltage generated by turning on/off a second switching element pair that is connected to a second DC power source. Polarities of the first and second secondary windings of the second transformer are set so that a voltages of each of the first and second secondary windings becomes additive to a voltage of the secondary winding of the first transformer.

Abstract: A light module includes a plurality of light sources for generating light, a power controller, a bridge converter, a first piezoelectric transformer, a second piezoelectric transformer, a resonance balance circuit, and a protection circuit. The power controller is used for generating a power driving signal based on a control signal. The bridge converter is used for generating a supply voltage signal based on the power driving signal. The first piezoelectric transformer is used for transforming the supply voltage signal into a first driving voltage signal to a first end of each of the plurality of lamps. The second piezoelectric transformer is used for transforming the supply voltage signal into a second driving voltage signal to a second end of each of the plurality of lamps.

Abstract: A driving device for driving discharge lamps (14) includes a first pulse circuit (11), a second pulse circuit (13), and a primary driving circuit (12). The first pulse circuit includes an input end, a first output end (1), and a second output end (2). The second pulse circuit includes an input end, a third output end (3), and a fourth output end (4). The primary driving circuit is connected between the first pulse circuit and the second pulse circuit for generating drive signals. The second output end of the first pulse circuit is connected to the third output end of the second pulse circuit, and the fourth output end of the second pulse circuit is connected to ground.

Abstract: A lamp current balancing device comprises an electronic power switch, a transformer, a current transformer and a pulse width modulation (PWM) IC; the transformer having a primary side connected to the electronic power switch and both ends of a secondary side connected to one end of each one of two lamps respectively, with another end of each one of the two lamps connecting to one end of a primary side of the current transformer respectively, the PWM IC being coupled between a secondary side of the current transformer and the electronic power switch; since the two lamps being cascaded in series with a same current flowing through them, thus providing current balancing capability, furthermore, the current transformer being used to detect an operating current of the lamps and to feed back the operating current to the PWM IC, the PWM IC receiving and processing the operating current to obtain a control signal, then outputting the control signal to the electronic power switch to control a pulse width outputted by

Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, efficient, and good performing. Embodiments include configurations that are applicable to any number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple lamps in parallel. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.

Abstract: A protective and measure device for multiple cold cathode fluorescent lamps includes an electronic ballast functioning as a high-frequency power source for driving multiple cold cathode fluorescent lamps (CCFLs), primarily by parallel connecting one end of each of a plurality of CCFL to a measure element to measure the LED power source provided by the measure element's photocoupler, and concurrently serially connect the photocoupler's collect-emitter terminal, followed by employing comparators to assess the open circuit, over current, and under current among multiple cold cathode fluorescent lamps. Said electronic ballast serves to protect CCFLs, and thus contribute to the quality and protection required for large LCD monitors.

Abstract: A pathway lighting system has self-contained, battery up scaled lighting modules (20), each module including at least one secondary coil. A plurality of primary coils are housed within a carrier assembly (1) together with voltage circuitry (14). Primary and secondary coils, positioned in the carrier assembly and in the lighting modules and the respectively allow electricity to flow between these members. The secondary coil output voltage is able to be rectified with the use of a rectification circuit, housed in the lighting module. Upon a mains failure, a battery charger/changeover circuit would switch the power requirements of the light sources inside the pathway lighting module over to internal back up batteries.

Abstract: A technique for driving one or more EEFLs, having first and second ends, in a bank of EEFLs involves driving the EEFLs at both the first and second ends. In a non-limiting embodiment a device constructed according to the technique includes a bank of EEFLs connected in parallel. The device further includes a first transformer, wherein a secondary winding of the first transformer is coupled to the first end of the bank of EEFLs. The device further includes a second transformer, wherein a secondary winding of the second transformer is coupled to the second end of the bank of EEFLs.

Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, efficient, and good performing. Embodiments include configurations that are applicable to any number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple lamps in parallel. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.

Abstract: A power supply arrangement is provided for supplying power to a plurality of back and/or edge illumination devices (5) in a liquid crystal display unit (1), comprising a mains connection (7), a power converter (6) and at least one inverter (8). The power converter (6) is arranged to convert an AC voltage input to a DC voltage output, and the inverter (8) is connected to said DC voltage output, and arranged to convert said output to a DC voltage level adequate for driving said illumination devices (5). Furthermore, the inverter (8) is provided with mains isolation. By virtue of this arrangement, no conventional adapter is required, and the LCD can be connected directly to the mains. The conversion down to a low DC voltage is eliminated, without violating the current-limitation safety requirements. This leads to a more effective power supply.

Abstract: An apparatus and methods for balancing current in multiple negative impedance gas discharge lamp loads. Embodiments advantageously include balancing transformer configurations that are relatively cost-effective, reliable, and efficient. Embodiments include configurations that are applicable to an unrestrained number of gas discharge tubes, such as cold cathode fluorescent lamps. The balancing transformer configuration techniques permit a relatively small number of power inverters, such as one power inverter, to power multiple paralleled lamps or paralleled groups of lamps with balancing transformers coupling the lamps or groups of lamps in a zigzag topology. One embodiment of a balancing transformer includes a safety winding which can be used to protect the balancing transformer in the event of a lamp failure and can be used to provide an indication of a failed lamp.

Abstract: A backlight inverter for an LCD panel which is capable of detecting a fault in a transformer device or an open-lamp condition and performing a control operation to stop its operation upon detecting the fault in the transformer device or the open-lamp condition. The inverter supplies a PWM signal through a switch in normal operation. The inverter also detects a voltage corresponding to current flowing through each lamp in a lamp device and determines from the detected voltage whether the open-lamp condition has occurred. The inverter further detects a voltage at a midpoint of secondary windings of the transformer device and determines from the detected voltage whether the fault exists in the transformer device. In the event of the open-lamp condition or the fault in the transformer device, the inverter turns off the switch.

Abstract: An energy-saving light marking device with low power consumption including a head transformer (10) where the primary winding (12) is powered by an alternating current source and several marking lamps in series (14-1 to 14-3) connected to the terminals of the secondary winding (13) of the head transformer, each of the marking lamps being a fluorescent lamp (16-1 to 16-3) powered by the secondary winding of a second transformer (18-1 to 18-3), the primary windings of all the secondary transformers of the marking lamps being connected in series between the terminals of the head transformer's secondary winding (13). The starting of each of the fluorescent lamps (16-1 to 16-3) is provided by the voltage surge generated at the terminals of the secondary winding of the secondary transformers (18-1 to 18-3) when the primary winding of the secondary transformers is powered while the lamps are not yet started.

Abstract: A airport runway lighting system, including a power source (10) supplying a constant current to a primary circuit (12) and several marking lights (14-1 to 14-6) each being connected to the primary circuit by a current transformer (16-1 to 16-6), the secondary winding of which supplies the lamp current. At least several adjacent transformers form a multiple assembly without a connection cable. Each transformer features a built-in male connector and a female plug or two built-in female plugs. The transformers are stacked to form the multiple assembly, the male connector of one of the transformers being inserted into the female plug of the immediately adjacent transformer, the male connector of the first transformer and the female plug of the last transformer being connected in series to the primary circuit.

Abstract: An incandescent lamp is designed to operate at lower than the AC line voltage and includes a voltage conversion circuit for lowering the line voltage to the operating voltage of the lamp. The circuit includes an output transformer which is disposed in the screw base of the lamp, the remainder of the circuit, which is high-temperature-intolerant, being disposed outside the base and the envelope of the lamp. In a reflectorized embodiment of the lamp, the high-temperature-intolerant portion of the circuit is disposed adjacent to the mouth of the reflector envelope on the outer surface thereof and, in a non-reflectorized bulb embodiment, the high-temperature-intolerant portion is disposed between the envelope and a skirt which is connected to the base.

Abstract: A first intermediate direct voltage is generated from a current source or board voltage, and a second sinusoidal intermediate alternating voltage is generated with a current inverter. This intermediate alternating voltage is transformed by one or more transfer systems to the various triggering and maintaining voltages of different cold cathode discharge lamps. Frequency-synchronous dimming is regulated by the pulse-pause ratio of a pulse group regulator in a broad frame by optically commanded triacs which are triggered in the zero crossing. The preconditions for the starting and maintenance characteristics of the lamps are thus always ensured.

Abstract: Ballasting system for fluorescent lamps having improved energy transfer capability and which delivers a sinusoidal current waveform free of high order harmonics and induces a similar waveform into the power distribution system. The system includes a low leakage reactance auto-transformer which is tuned to the line frequency, and a separately-wound heating transformer and means for switching energy from the heating transformer each half cycle.

Abstract: A device for regulating the intensity of light emitted by a lamp includes a core of magnetic material, a first electrical circuit having a primary inductor wrapped around at least a portion of the core of magnetic material, and a second electrical circuit having a secondary inductor wrapped around at least a portion of the core of magnetic material. The first electrical circuit is designed for electrical connection to the lamp, and the primary inductor is arranged in the first electrical circuit in a manner such that a variation in the inductance of the primary inductor will cause a corresponding variation in the intensity of light emitted by the lamp. The second electrical circuit includes a control device (e.g.