Abstract: A DC to AC inverter used in a solar cell power system can include an improved control scheme for cooling itself and optimizing power output.

Abstract: An apparatus includes an inverter including a high-side switch coupled to a low-side switch, the inverter generating a time-varying drive current from a plurality of drive control signals, a positive rail voltage, and a negative rail voltage wherein controlling the switches to generate the time-varying drive current produces a potential transitory overshoot condition for one of the switches of the inverter; a drive control, coupled to the inverter, to generate the drive control signals and to set a level of each of the rail voltages responsive to a plurality of controller signals; and a controller monitoring one or more parameters indicative of the potential transitory voltage overshoot condition, the controller dynamically adjusting, responsive to the monitored parameters, the controller signals to reduce a risk of occurrence of the potential transitory voltage overshoot condition.

Abstract: A solid state relay has independent charge pumps isolating each gate of a full bridge to achieve faster and proper gate turn on. The low side MOSFETs of the bridge are the current sensing device reducing loss and allowing a device controlled by the relay to achieve peak performance. Dynamic braking is achieved by the two low side MOSFETs being fully conducted and applying a load across the DC motor. Addition of a microprocessor to the device provides undervoltage sensing, current vs time readings, motor stall sensing, and motor temperature sensing. Motor temperature is detected by checking impedance of the motor at microsecond pulses to see if the motor is getting hot.

Abstract: Optimal operating techniques are disclosed for using coreless printed-circuit-board (PCB) transformers under (1) minimum input power conditions and (2) maximum energy efficiency conditions. The coreless PCB transformers should be operated at or near the ‘maximum impedance frequency’ (MIF) in order to reduce input power requirement. For maximum energy efficiency, the transformers should be at or near the “maximum efficiency frequency” (MEF) which is below the MIF. The operating principle has been confirmed by measurement and simulation. The proposed operating techniques can be applied to coreless PCB transformers in many circuits that have to meet stringent height requirements, for example to isolate the gates of power MOSFET and IGBT devices from the input power supply.

Abstract: A synchronization detection PLL section generates an ON synchronized signal formed as a result of synchronization control based on a diode ON synthesized signal. The synchronization detection PLL section also generates an OFF synchronized signal formed as a result of synchronization control based on a diode OFF synthesized signal. A stator gate instruction generator PWM section generates a gate instruction signal for controlling the switching of a switching element on the basis of the ON synchronized signal and the OFF synchronized signal.

Abstract: In a grid-tie inverter, the DC input is phase and pulse-width modulated to define multiple phase shifted voltage pulses with the width of each pulse being modulated according to the grid AC amplitude for the corresponding portion of the AC phase.

Abstract: A resonant converter is provided which may be used for supplying power to the primary conductive path of an inductively coupled power transfer (ICPT) system. The converter includes a variable reactive element in the resonant circuit which may be controlled to vary the effective inductance or capacitance of the reactive element. The frequency of the converter is stabilised to a nominal value by sensing the frequency of the converter resonant circuit, comparing the sensed frequency with a nominal frequency and varying the effective inductance or capacitance of the variable reactive element to adjust the converter frequency toward the nominal frequency.

Abstract: A switching power supply exhibits high conversion efficiency and facilitates reducing the size thereof. The switching power supply includes a half-bridge circuit including a first series circuit formed of switching devices Q1 and Q2 and connected between the output terminals of a DC power supply; and a second series circuit connecting primary inductance Lr1 of transformer T1, primary inductance Lr2 of transformer T2 and capacitor Cr in series. The second series circuit is connected between the output terminals of the half-bridge circuit, and is made to conduct a series resonance operation. The switching devices Q1 and Q2 is controlled at the ON-duties of 0.5 for reducing the breakdown voltages of rectifying diodes D1 and D2 on the secondary side of transformers T1 and T2 and for improving the conversion efficiency of the switching device.

Abstract: A converter to supply an AC voltage and current from three DC voltages comprising two switching units provided with first switching means connected between an input and a switching output, said converter comprising, for each switching unit, second switching means connected between said switching unit and a modulated signal output, and a switching aid circuit, said converter comprising control means acting on the second switching means associated with the switching unit that is connected to the voltage input of opposite sign to the sign of said AC voltage to establish turn-off of said second switching means when said AC voltage and said AC current are of opposite signs. An uninterruptible power supply comprising the converter described above.

Abstract: Single-phase full bridge boost converter systems and methods are provided. One system includes a direct-quatrature (D-Q) control system configured to generate a control voltage (vcon) including direct-phase and quadrature-phase voltage components. The system also includes a comparator configured to compare vcon to a carrier waveform voltage, generate switching commands based on the comparison, and transmit the switching commands to a current switch. Another system includes a boost converter including multiple switches coupled to a load and an AC voltage source. The switches are configured to provide charging current to the load in response to receiving switching commands. A D-Q control system configured to receive and delay an ia value, and issue switching commands based on the ia and delayed ia value is also included.

Abstract: The present invention discloses a resonance circuit for use in an H-bridge DC-DC converter, the resonance circuit comprising: an H-bridge converter, capable of converting unstable DC power into stable DC power; a first resonance circuit, disposed on a buck side of the H-bridge converter for reducing the turn-off loss of a first active switching element; and a second resonance circuit, disposed on a boost side of the H-bridge converter for reducing the turn-on loss of a second active switching element. The H-bridge converter comprises: a first active switching element and a second active switching element; a coupled inductor with dual windings capable of storing energy; and a first passive switching element and a second passive switching element.

Abstract: A DC power source voltage is supplied to a center tap of a primary winding, and first and second semiconductor switches alternately turned on are disposed between each of both ends of the primary winding and a common potential point, and a current flowing through a load is fed back and PWM control of each of the semiconductor switches is performed. Also, snubber circuits are respectively connected between a ground and the center tap of the primary winding, and an abnormal high voltage at the time of switching is reduced. Also, a parallel running of plural inverters is simply performed by disposing PWM comparators corresponding to the first and second semiconductor switches.

Abstract: An inverter (1) for feeding electric power into a utility grid (7) or into a load is described. The inverter (1) contains direct voltage inputs (2, 3), one first intermediate circuit (8) connected thereto and comprising two series connected capacitors (C1, C2) that are connected together at a ground terminal (14), two alternating voltage outputs (5, 6) of which one at least is provided with a grid choke (L1) and one bridge section (10).

Abstract: An exemplary inverter circuit (200) includes a direct current (DC) input terminal (210); a transformer (230) including a first primary winding (231) and a second primary winding (232); a first switch transistor (240); a second switch transistor (250); a pulse generator (260) providing pulse driving signals to the first switch transistor and the second transistor respectively; and a resistor (29). The first primary winding and the second primary winding share a tap (235), the tap is connected to the DC input terminal via the resistor. A drain electrode of the first switch transistor is connected to the tap via the first primary winding, and a drain electrode of the second switch transistor is connected to the tap via the second primary winding.

Abstract: A power converter for converting an input voltage (Vin) into an output voltage (Vout), comprising a first supply potential and a second supply potential established by the input voltage, and at least one primary winding having two terminals, a center tap arranged between the two terminals and connected to the first supply potential, and at least one secondary winding magnetically coupled to the primary winding for providing at least one output voltage (Vout) and a first controllable switch connected between the second supply potential and one terminal of the primary winding and a second controllable switch connected between the second supply potential and the other terminal of the primary winding and a third controllable switch connected between the second supply potential and the one terminal of the primary winding and a fourth controllable switch connected between the second supply potential and the other terminal of the primary winding, and a control unit for controlling the switches such that the first, s

Abstract: Provided is a bidirectional DC/DC converter which can control a boost voltage in a wide range. The DC/DC converter includes: three series circuits formed by a first to a sixth switch, each two of which are connected in series between a plus terminal and a minus terminal of a high voltage side; two transformers in which primary windings are connected in series and input terminals of the primary windings are connected to connection points of the switching elements; and a seventh to a tenth switch. The transformers have secondary windings, each of which is divided at the middle point. The middle points are connected to a minus terminal of a low voltage side. Respective terminals of the secondary windings are connected to a plus terminal of the low voltage side by the seventh to the tenth switches.

Abstract: A circuit for transmitting signals includes a transformer having an input side and an output side, the input side having a first end and a second end. A first transistor is coupled to the first end of the transformer, the first transistor being configured to provide a first signal to the first end in response to an input signal transitioning to a first state. A second transistor is coupled to the second end of the transformer; the second transistor being configured to provide a second signal to the second end in response to the input signal transitioning to a second state. The output side is configured to output differential signals according to the first and second signals applied to the transformer.

Abstract: The invention provides a power supply apparatus for supplying electric power to a capacitive load. The apparatus has a transformer, a positive half-period driver and a negative half-period driver supplying positive and negative half-periods of voltage to the first coil. The second coil forms an electric resonance circuit and supplies electric voltage to the load. Zero crossings of the voltage supplied to the first coil are determined from a third coil on the transformer, and alternation between positive and negative half-periods of voltage supplied to the first coil is done at the zero crossings of the voltage supplied to the first coil.

Abstract: A converter for a wind energy installation and a method. The converter includes an inverter which drives a generator via a plurality of phases and an intermediate circuit having an intermediate-circuit voltage between an upper and a lower intermediate-circuit potential. The generator is driven with phase potentials at a variable frequency. A shift value is calculated between an extreme phase potential and one of the intermediate-circuit potentials, a separation value is determined between a middle phase potential and the closest intermediate-circuit potential, and an additional voltage is generated using the separation value as amplitude. The phase potentials are shifted through the shift value and the additional voltage is added to the middle phase potential. Accordingly, the switching elements in the converter do not need to be clocked in every second half-cycle resulting in reduced switching losses and increased current load capacity of the converter.

Abstract: A high frequency power supply includes a DC source unit (19) that outputs a DC voltage Vdc having an output level corresponding to a target voltage, an oscillation unit (13) that outputs a high frequency voltage signal having an output level corresponding to a target power, an amplification unit (14) that includes a plurality of amplifying elements, and amplifies and outputs the high frequency voltage signal output by the oscillation unit (13) utilizing the DC voltage output by the DC source unit (19), an output voltage detection unit (21) that detects an amplitude of the voltage between the amplified-side terminals of the amplifying elements in the amplification unit (14), or an amplitude of a voltage that is proportional to the amplitude of the voltage between the amplified-side terminals, and a target voltage decision unit (22) that decides a target value of the DC source voltage Vdc to be outputted by the DC source unit (19) based on the detection result from the output voltage detection unit (21).

Abstract: A DC to AC power converter is disclosed. The power converter has four power-switching devices, two diodes, a step-up and isolation transformer, a capacitor-choke filter and a controller. Two power-switching devices located on the primary side of the transformer are switched to provide alternate cycles of an ac current to the primary side of the transformer, which magnetically couples the ac current to the secondary side of the transformer. Two power-switching devices on the secondary side of the transformer are switched to alternately allow the forward and return ac currents from the secondary side of the transformer in the output path to a load connected to the output of the DC to AC power converter.

Abstract: A switched current power converter includes an input power source, an output terminal, and a plurality of current stages. Each of the current stages includes a converter coupled to the input power source for providing a current and a switch circuit that selectively couples the current in such current stage to the output terminal. A control circuit decouples the input power source from the current stage converters upon detection of a low load condition. Optionally, the power converter includes a low load circuit responsive to the control circuit that selectively couples current to the output terminal during the low load condition.

Abstract: A drive circuit includes a plurality of output drive terminals and a plurality of push-pull circuit stages. Each of the push-pull circuit stages includes a pair of complementary transistors having a common terminal connected to a respective output drive terminal. The drive circuit further includes a plurality of first transistors connected in series with at least one of the pair of complementary transistors of the push-pull circuit stages, respectively, and a common second transistor. The common second transistor is connected with each of the plurality of first transistors to form a current mirror circuit.

Abstract: A DC power source voltage is supplied to a center tap of a primary winding, and first and second semiconductor switches alternately turned on are disposed between each of both ends of the primary winding and a common potential point, and a current flowing through a load is fed back and PWM control of each of the semiconductor switches is performed. Also, snubber circuits are respectively connected between a ground and the center tap of the primary winding, and an abnormal high voltage at the time of switching is reduced. Also, a parallel running of plural inverters is simply performed by disposing PWM comparators corresponding to the first and second semiconductor switches.

Abstract: An inverter (1) for feeding electric power into a utility grid (7) or into a load is described. The inverter (1) contains two direct voltage inputs (2, 3), one first intermediate circuit (8) connected thereto and comprising two series connected capacitors (C1, C2) that are connected together at a ground terminal (14), two alternating voltage outputs (5, 6) of which one at least is provided with a grid choke (L1) and one bridge section (10). In accordance with the invention, a second intermediate circuit (9) that is devised at least for selectively boosting the direct voltage and is intended for supplying the bridge section (10) with positive and negative voltage is interposed between the first intermediate circuit (8) and the bridge section (10).

Abstract: An inverter (1) for feeding electric power into a utility grid (7) or into a load is described. The inverter (1) contains direct voltage inputs (2, 3), one first intermediate circuit (8) connected thereto and comprising two series connected capacitors (C1, C2) that are connected together at a ground terminal (14), two alternating voltage outputs (5, 6) of which one at least is provided with a grid choke (L1) and one bridge section (10).

Abstract: In a two stage inverter providing power to a load, a first stage component is operable to receive a first voltage input and a first control input to generate a first voltage output, which is higher than the first voltage input. The first control input is indicative of the power provided to the load. The first voltage output varies in response to a change in the first voltage input by a predefined function. A second stage component of the inverter is operable to receive the first voltage output and a second control input to generate the power as an output. The second control input is indicative of the power provided to the load. A controller component of the inverter is operable to receive a feedback input indicative of the power required by the load and generates the first and second control inputs.

Abstract: A power converter apparatus, such as an uninterruptible power supply (UPS), includes an inverter having an input coupled to a first DC bus and a second DC bus and configured to generate an AC output with respect to a neutral terminal at a phase output terminal thereof. The apparatus further includes first and second neutral coupling circuits, each configured to selectively couple the first DC bus and the second DC bus to the neutral terminal, and a control circuit configured to cause interleaved operation of the neutral coupling circuits.

Abstract: Described is an inverter device suitable for driving a cold cathode fluorescent lamp (CCFL), comprising a transformer having a primary winding and a secondary winding. The primary winding has two terminals connected to a return-path terminal of a direct current (DC) power source through a second switch and a third switch, respectively, and a center tap connected to an output of the DC power source through a first switch. A signal controlling unit is further included to control the switches in such a manner that the second and third switches are on concurrently or alternatively in cooperation with the first switch. As such, an alternating current (AC) power is fed to the primary winding of the transformer and an output of the transformer is supplied to the CCFL.

Abstract: A switched current power converter including an input power source, an output terminal, and a plurality of current stages. Each current stage includes a converter coupled to the input power source for providing a current, and a switch circuit for selectively coupling the current in such current stage to the output terminal. A control circuit selectively decouples the input power source from less than all of the current stage converters upon detecting a low load condition, thereby reducing circulating current losses and improving operating efficiency under low load conditions.

Abstract: An inverter component layout and mounting bracket are disclosed which allow for electrical components, or the inverter as a whole to be replaced easily in the field. The disclosed mounting bracket and component layout also improve the heat rejection properties of the inverter.

Abstract: A DC power source voltage is supplied to a center tap of a primary winding, and first and second semiconductor switches alternately turned on are disposed between each of both ends of the primary winding and a common potential point, and a current flowing through a load is fed back and PWM control of each of the semiconductor switches is performed. Also, snubber circuits are respectively connected between a ground and the center tap of the primary winding, and an abnormal high voltage at the time of switching is reduced. Also, a parallel running of plural inverters is simply performed by disposing PWM comparators corresponding to the first and second semiconductor switches.

Abstract: A switching power supply circuit includes a plurality of switching converters, each including a partial resonance voltage circuit combined with a current resonance type switching converter using a half-bridge connection system. For changeover control, a rectification circuit serves as a voltage doubler rectification circuit at an AC voltage less than or equal to 150V, but serves as a full-wave rectification circuit at an AC voltage greater than or equal to 150V. The voltage output of the converters is fed back to a rectification current path by a power factor improving transformer, the rectification current being interrupted by means of a rectification diode to expand the conduction angle of the AC input current. A DC switch circuit in the rectification current path is switched between on and off conditions in response to the input of a predetermined starting signal to control the starting order of the secondary side DC output voltage.

Abstract: A programmable AC/DC power converter receives a plurality of input voltages and outputs a single voltage from an input voltage system. A transformer receives the single voltage. One of the plurality of input voltages is provided at a center tap of a secondary winding of the transformer. A transformed voltage is output. A rectifier receives the transformed voltage and outputs a DC voltage. A buck regulator receives a DC voltage, creates a regulated voltage, and outputs the regulated voltage and a regulated current to a portable appliance. A error correction system receives a programming signal and regulated signals and verifies that the regulated signal to programming signal ratio is within an acceptable range.

Abstract: In a two stage inverter providing power to a load, a first stage component is operable to receive a first voltage input and a first control input to generate a first voltage output, which is higher than the first voltage input. The first control input is indicative of the power provided to the load. The first voltage output varies in response to a change in the first voltage input by a predefined function. A second stage component of the inverter is operable to receive the first voltage output and a second control input to generate the power as an output. The second control input is indicative of the power provided to the load. A controller component of the inverter is operable to receive a feedback input indicative of the power required by the load and generates the first and second control inputs.

Abstract: A controller for controlling at least two power circuits comprises a phase-shift selector for generating a reference signal according to variable input signals, the reference signal is programmed to indicate an amount of phase-delay according to a number of CCFL power circuits connected; and a pulse generator for receiving the reference signal and generating a pulse signal CLK in response to the received reference signal, the pulse signal is coupled to the CCFL power circuits connected for initiating the operation of the CCFL power circuits. The controller is used to control energy supplying to an electrical circuit comprising multiple CCFL power circuits and is more particularly to provide phase delay to the electrical circuit. Usually, the electrical circuit is applied to display devices, such as liquid crystal display monitors, liquid crystal display computers and liquid crystal display televisions.

Abstract: A wide-range compatible voltage resonant converter provides high efficiency and allows use of low-breakdown-voltage products for a circuit. The voltage resonant converter is provided with a secondary-side parallel resonant circuit and a secondary-side series resonant circuit, and a loose coupling state is established in which the coupling coefficient of an isolation converter transformer is about 0.7 or less. Thus, a constant-voltage control characteristic is obtained as a sharp unimodal characteristic, which narrows the switching frequency control region required for stabilization of an output voltage. In addition, a primary-side parallel resonant frequency, a secondary-side parallel resonant frequency and a secondary-side series resonant frequency are set so that a favorable power conversion efficiency is obtained. Moreover, an active clamp circuit is provided to suppress the peak level of a resonant voltage pulse to thereby allow use of low-breakdown-voltage products for a switching element and so on.

Abstract: A DC converter alternately turns on and off a main switch Q1 connected in series with a primary winding P1 of a transformer T and a sub-switch Q2 contained in a series circuit connected to each end of the primary winding P1 of the transformer T or to each end of the main switch Q1, rectifies and smoothes a voltage of a secondary winding S1 of the transformer T, and provides a DC output. The DC converter includes a time difference detection circuit 13 to detect an interval between when the main switch Q1 reaches a minimum voltage after the sub-switch Q2 is turned off and when the main switch Q1 is turned on and a first delay circuit 14 to delay the ON timing of the main switch Q1 according to an output from the time difference detection circuit 13 so that the main switch Q1 is turned on at around the minimum voltage.

Abstract: A description is given of a power supply unit, an X-ray device having a power supply unit, and a method of controlling a power supply unit. In order also to control non-linear control paths, such as of a power supply unit operated with mixed-mode modulation, it is proposed that the control device be designed as a digital control device which calculates at least one correcting variable. The control device processes at least a first actual value Uout, which depends on the output voltage. A time difference value is calculated from two sample values of the first actual value Uout and is multiplied by a first controller coefficient Kout. The value of the first controller coefficient can in this case change as a function of the operating point of the power supply unit.

Abstract: A programmable AC/DC power converter receives a plurality of input voltages and outputs a single voltage from an input voltage system. A transformer receives the single voltage. One of the plurality of input voltages is provided at a center tap of a secondary winding of the transformer. A transformed voltage is output. A rectifier receives the transformed voltage and outputs a DC voltage. A buck regulator receives a DC voltage, creates a regulated voltage, and outputs the regulated voltage and a regulated current to a portable appliance. A error correction system receives a programming signal and regulated signals and verifies that the regulated signal to programming signal ratio is within an acceptable range.

Abstract: A switching power conversion circuit comprises a saturable load assembly, a first switching inductance coil assembly and a second switching inductance coil assembly. The saturable load assembly is composed of a load and a saturable reactor. The first switching inductance coil assembly is connected to the saturable load assembly and a first potential. The second switching inductance coil assembly is magnetically coupled with the first switching inductance coil assembly, and is connected to the first switching inductance coil assembly and a second potential. When the first and second switching inductance coil assemblies are power switched, the saturation effect of the saturable reactor is exploited to let the terminal potential of the saturable reactor drop before switching, hence letting the terminal potential of the transfer switch be zero.

Abstract: An over-power protection apparatus for self-excited power converter comprises a soft-start unit, an adjusting unit and a timing unit. A PWM unit of the self-excited power converter generates a switching signal in response to a compensating signal of the soft-start unit to control the output power of the self-excited power converter. The soft-start unit couples to the adjusting unit. The adjusting unit drives the soft-start unit and the PWM unit for modulating the switching signal to reduce the pulse width of the switching signal and the output power of the self-excited power converter once the short-circuit and over-load are happened at the output of the self-excited power converter. In the meantime, a timing unit starts to count. The timing unit drives the self-excited power converter to stop supplying the power source after the counting and the over-power lasting for a period of time.

Abstract: An input stage circuit of a three-level DC/DC converter is provided. The input stage circuit uses metal-oxide-semiconductor field effect transistors (MOSFETs) to discharge a flying capacitor to maintain the voltage across the flying capacitor at a half of the input voltage. Not only can the input stage circuit solve the high voltage issue across the flying capacitor in the prior art, but the circuit is able to operate normally without increasing power consumption during discharging, thereby avoiding problems of the prior art.

Abstract: A multi-stage, push-pull driven, resonant DC-AC converter ties the center-taps of primary windings of respective push-pull stages together, and drives each center-tap with a current source. Tying the center-taps of the primary windings of the respective DC-AC converters' transformers together forces the voltages at these locations to be the same, so as to achieve mutual resonant synchronization between the two stages. Connecting the center-taps to a current source provides the necessary power for each stage and allows for a variation in current between stages, as the center-tap voltages track one another. The tied-together center-tap voltage is monitored to obtain the zero voltage switching required for efficient operation of switching devices of each DC-AC converter stage.

Abstract: An inverter power supply system includes a half-bridge inverter circuit which includes a first switching element, a second switching element, a first auxiliary capacitor and a second auxiliary capacitor for converting a DC voltage from a DC power supply circuit to an AC voltage. An output control circuit outputs a first output control signal and a second output control signal with a phase difference of a half cycle to control the inverter circuit. An inverter driving circuit turns on the first (or second) switching element when the first (or second) output control signal turns ON while turning off the first (or second) switching element upon lapse of a first (or second) delay time for allowing the first (or second) auxiliary capacitor to discharge to a predetermined level after the first (or second) output control signal turns OFF.

Abstract: A frequency converter includes a transistor pair having a first transistor and a second transistor respectively having collector terminals commonly connected to each other and emitter terminals commonly connected to each other, the commonly-connected collector terminals of the transistor pair being connected to a power supply terminal by way of a first resistor, a third transistor having a collector terminal connected to the power supply terminal by way of a second resistor and an emitter terminal connected to the commonly-connected emitter terminals of the transistor pair, a third resistor having an end connected to the commonly-connected emitter terminals of the transistor pair, and another end grounded by way of a constant current source, and an output terminal connected to the commonly-connected collector terminals of the transistor pair.

Abstract: A controller for controlling at least two power circuits comprises a pulse generator and a selector. The pulse generator generates a first pulse signal which is coupled to a first power circuit of the at least two power circuits for initiating the operation of the first power circuit. The first power circuit then outputs a second pulse signal to a second power circuit of the at least two power circuits to initiate the operation of the second power circuit. The selector generates a reference signal which is coupled to each of the at least two power circuits for indicating a number of power circuits controlled. The controller is used to control energy supplying to an electrical circuit comprising multiple inverters and is more particularly to provide phase shifts to the electrical circuit. Usually, the electrical circuit is applied to display devices, such as liquid crystal display monitors, liquid crystal display computers and liquid crystal display televisions.

Abstract: A compact high-power pure-sinewave inverter amenable to mass manufacturing techniques. Methods for increasing the power rating, power density and/or power conversion efficiency of a sinewave-modulated pulse-width-modulated (PWM) inverter having a either half-bridge or full-bridge topology, including minimizing uncoupled inductances and loop inductances in the primary winding(s) by employing either ribbon-like conductors having a high crossectional aspect ratio or litz-wire. A compact linear heatsink adapted to cool a row of semiconductor devices (such as inverter switches) mounted on a high-current printed circuit board. Methods for inexpensive manufacture of a fluid-cooled linear heat sink. A transformer including a filter inductor core.

Abstract: An inductive device comprises an electric winding component having a generally toroidal shape, and a plurality of discrete magnetic components at least partially embracing the electric winding component so as to complete a magnetic flux path and to form at least one gap between end portions of the plurality of discrete magnetic components.

Abstract: An efficient power conversion circuit for driving a fluorescent lamp uses a minimum pulse generator circuit to control the minimum on-time of a time modulated signal to increase the dimming range of the fluorescent lamp operating over a wide range of temperature and supply voltage. A minimum number of lamp current cycles with respective amplitudes above a preset threshold is typically required to avoid flickering or shimmering during minimum brightness. The minimum pulse generator circuit counts the lamp current cycles and adjusts the on-time accordingly to guarantee the minimum number of cycles with respective amplitudes above a preset threshold under all operating conditions.