Abstract: A first chopper circuit generates a first sequence of square wave voltages having a voltage level that changes to a positive side by chopping a direct current voltage at a system frequency. A second chopper circuit generates a second sequence of square wave voltages having a voltage level that changes to a negative side by chopping a direct current voltage at a frequency twice as high as the system frequency. The second chopper circuit further generates a third sequence of square wave voltages having a voltage level that changes to the positive and negative side in turns in the manner of sinusoidal wave by summing the first sequence of square wave voltages and the second sequence of square wave voltages.

Abstract: In a low-voltage power supply circuit for illumination that rectifies an ac power supply by means of a rectifier circuit, that controls this rectified output by means of a power-factor control circuit, and that supplies a low-voltage power supply for illumination, the power-factor control circuit is composed of a step-down circuit and is further provided with a current-limiting capability.

Abstract: Methods and systems for transforming electric power between two or more portals. Any or all portals can be DC, single phase AC, or multi-phase AC. Conversion is accomplished by a plurality of bi-directional conducting and blocking semiconductor switches which alternately connect an inductor and parallel capacitor between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then the energy is transferred out of the inductor to one or more output portals and/or phases, with said parallel capacitor facilitating “soft” turn-off, and with any excess inductor energy being returned back to the input. Soft turn-on and reverse recovery is also facilitated. Said bi-directional switches allow for two power transfers per inductor/capacitor cycle, thereby maximizing inductor/capacitor utilization as well as providing for optimum converter operation with high input/output voltage ratios. Control means coordinate the switches to accomplish the desired power transfers.

Abstract: A piezoelectric transformer driving device including: an oscillator; a frequency-divider outputting a pulse by dividing a clock signal from the oscillator by a frequency-divide ratio received thereto; a switching element driven by the pulse and intermittently applying a voltage to a primary side of a piezoelectric transformer; a frequency-divide ratio instructing unit holding a frequency-divide ratio instruction value of a real number having an integer part and an fractional part; a binarization unit binarizing the frequency-divide ratio instruction value into two different integer frequency-divide ratios and selectively outputting the frequency-divide ratios. The binarization unit adjusts an appearance ratio of the frequency-divide ratios such that an average of the frequency-divide ratios output from the binarization unit is equal to an average of the frequency-divide ratio instruction value.

Abstract: Methods and apparatus are provided for generating low EMI display driver power supply. The methods and apparatus include switching circuits that utilize two groups of parallel circuit traces, each of which is coupled to one end of a switching device. The two groups of traces are configured to be interleaved with each other such that no two traces from either group are next to any other traces from the same group. When the switching device is activated, current flows through the circuit and charges an energy storage element. When the switching device is deactivated, the energy storage element discharges a portion of its energy to a second energy storage element and to the driver circuits. In another embodiment, an additional circuit trace is provided which is only connected on one end and is free floating on the other end to capture the majority of EMI remaining that was generated by the switching circuit.

Abstract: A controller of an AC/DC flyback switching power supply uses adaptive digital control approaches to control the switching operation of a BJT power switch based on primary-side feedback to regulate the secondary-side constant output voltage and output current, without using the input line voltage. Switching-cycle by switching-cycle peak current control and limit are achieved based on the sensed primary-side current rather than the input line voltage in both constant-voltage and constant-current modes, operating in PWM, PFM and/or combinations of a plurality of PWM and PFM modes. The controller IC does not need a separate pin and ADC circuitry for sensing the input line voltage.

Abstract: A comparator detects whether a feedback signal of an output voltage detecting circuit for a switching power supply circuit reaches a control voltage. A comparator detects an operating state of the switching power supply circuit, which is instructed by a switching instruction signal, by comparing the instruction signal with a reference voltage. The comparators are connected to a decision circuit which outputs to a control circuit a signal instructing a normal state until the feedback signal reaches the control voltage, and thereafter a signal instructing a normal state or a stand-by state that is instructed by the switching instruction signal. Thus, the control circuit makes the switching power supply circuit operate in a normal state until the output voltage reaches the control voltage. After the output voltage reaches the control voltage, the switching power supply circuit operated in an operation state instructed by the switching instruction signal to enable stable startup.

Abstract: An aircraft induction oven excitation arrangement includes at least one connection for an on-board power supply system, at least one power supply rectifier that can be connected to a phase of the power supply system, a converter that is arranged downstream of the at least one power supply rectifier and that includes a switching element, a controller that drives the at least one converter, a rectifier that is arranged downstream of the converter in order to produce an intermediate circuit voltage, an inverter that is connected to the intermediate circuit voltage. The switching element has a turn-on resistance Rdson ?about 0.1? and a self-capacitance ?about 200 pF at voltages of ?about 200 V across the switching element.

Abstract: A control system for a power factor correction circuit performs stabilized oscillation operation and suppresses switching frequency variation due to change of the AC power source. A control system includes a voltage error amplifier for outputting a voltage error signal obtained by amplifying a difference between a DC output voltage Vo and a command value Vref of the DC output voltage, a current command value generating circuit for outputting a current command value Vi for controlling the input current Iin, a comparator comparing an inductor current signal obtained by detecting an inductor current running in the switching element by a current detecting resistor with a magnitude of the output signal Vi from the multiplier, a timer circuit for setting an off-period of the switching element corresponding to the voltage Vd, and a reset-set type flip-flop circuit for setting an off-timing of the switching element after an elapse of the off-period.

Abstract: In a switching power supply apparatus, multiplier 9 multiplies error voltage Verr generated in voltage error amplifier 8 and input voltage Vin to generate first threshold signal Vth1 in-phase with and similar to input voltage Vin and having an amplitude proportional to error voltage Verr. Second threshold signal generator circuit 14 generates second threshold signal Vth2 from first threshold signal Vth1. Switching device 7 is turned on and off so that the inductor current may change between first and second threshold signals Vth1 and Vth2. The switching frequency is detected and the proportional factor of first and second threshold signals Vth1 and Vth2 is changed to control the average switching frequency almost at a constant value for reducing the high frequency noises and the switching losses. The switching power supply apparatus facilitates reducing the noises and losses, improving the power factor thereof, and preventing the response performances thereof from being impaired.

Abstract: A power factor correction converter includes a diode bridge arranged to perform full-wave rectification on an AC input power supply, a switching element arranged to perform switching on an output voltage thereof, an inductor arranged to pass a current interrupted by the switching element and to accumulate and emit excitation energy, a diode, and a smoothing capacitor defining a step-up chopper circuit. A digital signal processing circuit detects a phase of an input voltage, and a switching frequency of the switching element is modulated in accordance with the phase. Accordingly, the switching frequency can be appropriately modulated without depending on an input voltage, so that a wide range of input voltages can be accepted while suppressing EMI noise with a peak generated in the switching frequency and higher-order frequency components thereof.

Abstract: A multiphase DC chopper converts an input voltage of an input capacitor into an output voltage of an output capacitor. The multiphase DC chopper has a plurality N of DC choppers connected in parallel between the input capacitor and the output capacitor in which case the nth DC chopper, with n?[1, . . . , N], providing on its output side an nth charge current for charging the output capacitor. A regulation device, which in each case regulates a phase difference signal of two charge currents, which sequentially charge the output capacitor to a value of 360°/N.

Abstract: This invention teaches power factor corrected 3-phase ac-dc power converters in which the duty-cycles are determined by “natural modulation”, that is, they are forced by a fixed algorithm that has been optimized for efficient switching. The duty-cycles do not regulate the output voltage but they do force the input currents to be proportionately correct for good power factor. A feedback control circuit modulates the effective turns-ratio of a variable dc-dc transformer to regulate the output voltage. For a buck converter, the most efficient duty-cycle is 100%, that is, the buck switch is always on. For a boost converter, the most efficient duty-cycle is 0%, that is, the boost switch is always off. “100% duty-cycle” as defined for a buck 3-phase ac input means that there is no off-time. The switch duty-cycles are as follows: The duty-cycle for the phase with the highest voltage magnitude (the dominant phase) is 100%, and sum of the duty-cycles of the other two phases equals 100%.

Abstract: An apparatus for coupling a switching mode power supply (SMPS) controller to a rectified line voltage. The apparatus includes a high-voltage startup transistor configured to provide a charging current during a startup phase of the SMPS controller and to provide substantially no current during a normal operation phase of the SMPS controller. A switch coupled to the high-voltage startup transistor. The switch receives a control signal from the SMPS controller, for turning off the switch during the startup phase and turning on the switch during the normal operation phase. A biasing device is connected in series with the switch and maintains the startup transistor in an off state when the SMPS controller is in the normal operation phase. A standby current in the apparatus is substantially lower when the SMPS controller is in the normal operation phase than the charging current in the apparatus when the SMPS is in the startup phase.

Abstract: Methods and systems for transforming electric power between two or more portals. Any or all portals can be DC, single phase AC, or multi-phase AC. Conversion is accomplished by a plurality of bi-directional conducting and blocking semiconductor switches which alternately connect an inductor and parallel capacitor between said portals, such that energy is transferred into the inductor from one or more input portals and/or phases, then the energy is transferred out of the inductor to one or more output portals and/or phases, with said parallel capacitor facilitating “soft” turn-off, and with any excess inductor energy being returned back to the input. Soft turn-on and reverse recovery is also facilitated. Said bi-directional switches allow for two power transfers per inductor/capacitor cycle, thereby maximizing inductor/capacitor utilization as well as providing for optimum converter operation with high input/output voltage ratios. Control means coordinate the switches to accomplish the desired power transfers.

Abstract: A power factor corrected (pfc) ac-dc converter has a modified boost input and a modified buck output. Unlike the prior art boost input, the boost switch returns to the output, not to ground. Unlike the prior art buck output stage, a third switch connects to the input. This allows much of the input current to pass through the converter to the output. There is no input current measurement, but nearly ideal power factor correction is achieved through “natural modulation.” A preferred pfc ac-dc converter uses a variable dc-dc transformer on its output, as a post regulator, to provide dielectric isolation and to provide voltage level shifting. The output of the pfc ac-dc converter has the control characteristics of a buck converter, so it is a natural mate for the variable dc-dc transformer. An ac-dc buck converter is most efficient at its maximum duty cycle. It cannot regulate for a lower input voltage, but it can reduce its duty-cycle to control for higher input voltages.

Abstract: An integrated circuit that includes a power stage and a driver stage, all stages using III-nitride power devices.

Abstract: Techniques are disclosed to control output power from a switching power supply. A sample power converter controller circuit includes a control circuit coupled to be coupled to a switch. The control circuit includes a current sense circuit to be coupled to a primary winding of an energy transfer element coupled to the switch. The control circuit also includes a measurement circuit to be coupled to a secondary winding of the energy transfer element. A feedback circuit is also included and is coupled to the control circuit and coupled to receive a feedback-signal derived from an output of a power converter. The feedback circuit is coupled to output a signal to the measurement circuit. An output of the measurement circuit and an output of the current sense circuit are coupled to control a switching of the switch to regulate a combination of an output voltage and an output current of the power converter.

Abstract: A negative voltage generating circuit includes a pulse generator U1, a switch, a resistor, a first capacitor, a first diode, a second diode, and a second capacitor. The pulse generator includes a positive voltage input pin coupled to a power supply, an oscillating output pin, and a negative voltage input pin. The switch includes a first terminal coupled to the oscillating output pin, a second terminal coupled to one terminal of the first capacitor, and coupled to the power supply via the resistor, and a third terminal being grounded. Another terminal of the first capacitor is coupled to the anode of the fist diode and the cathode of the second diode. The cathode of the first diode is grounded. The anode of the second diode is coupled to the positive voltage input pin of the pulse generator, and is coupled to ground via the second capacitor.

Abstract: This invention relates to a power module for a plug-in hybrid electric vehicle including an integrated converter having a rectifier changing AC to DC, a DC/DC converter changing from a first voltage to a second voltage, and a battery storing electrical energy. The integrated converter operates in three modes 1) AC plug-in charging mode, 2) boost mode supplying power from the battery to the electrical bus and 3) buck mode supplying power from the electrical bus to the battery. The integrated converter utilizes the same single inductor during each of the three operating modes to reduce cost and weight of the system.

Abstract: A synchronous machine regulator is provided to simplify an adjustment work of current distribution to thyristors, the synchronous machine regulator having a circuit board 32 mounting a gate drive circuit 33 for supplying a gate pulse to each of thyristor bridges constituting a plurality of thyristor rectifiers 44 connected in parallel and supplying excitation current to a field winding 2 of a synchronous machine 1, and phase control means 34 for controlling a phase angle of each gate pulse to be supplied to each thyristor, wherein the current distribution to thyristors is controlled by the phase control means 34.

Abstract: Choppers are provided respectively in the output stages of two diode bridges, and their output sides are connected in parallel to a smoothing capacitor. By controlling the operations of the two choppers, the currents which are allowed to be inputted to the diode bridges are made triangular waves of mutually opposite phases, or middle-phase waveforms of three phases.

Abstract: A hybrid constant current control system that uses both pulse width modulation (PWM) and pulse frequency modulation (PFM) control. When transitioning from constant voltage mode to constant current mode the present invention can continue to control using PWM. Thereafter, when the voltage has dropped, the present invention smoothly transitions to PFM mode. The point of transition is based upon the switching frequency and the lowest rated voltage of operation. The system and method avoids very short (narrow) Ton times which ensures accurate constant current (CC) control with bipolar junction transistor (BJT) devices. The present invention also avoids acoustic noise because the switching frequency is maintained at a high enough level to avoid such acoustic noise even when the energy transferred through the transformer is still substantial and the output voltage is not too low.

Abstract: An IGBT/FET-based energy savings device, system and method (1) wherein a predetermined amount of voltage below a nominal line voltage and/or below a nominal appliance voltage is saved, thereby conserving energy. Phase input connections (2) are provided for inputting analog signals into the device and system (1). A magnetic flux concentrator (3) senses the incoming analog signal (20) and a volts zero crossing point detector (5) determines the zero volts crossing point (21) of the signal (20). The positive half cycle (22) and negative half cycle (23) of the signal (20) are identified and routed to a digital signal processor (10) for processing the signal (20). The signal (20) is reduced by pulse width modulation and the reduced amount of energy is outputted, thereby yielding an energy savings for an end user.

Abstract: A DC chopper features a setting device, which sets a required current value signal being dependent on a filtered input voltage such that an oscillation of the input filter device and an oscillation of the current are phase-opposed. The DC chopper may further have a control device, which, depending on the input voltage, supplies a control signal and adds the control signal to the actual current value signal supplied to form a controlled actual current value signal. The DC chopper may optionally have a disconnection device, which receives a switch-off signal on the input side and, depending on the switch-off signal received, supplies a ramp disconnection signal, and an adding node which adds the actual current value signal to the ramp disconnection signal to form an elevated actual current value signal.

Abstract: A bi-directional boost circuit for power factor correction includes a power factor control circuit and a pair of diodes, a pair of inductors, and a pair of switches. A first diode, a second diode, a first inductor, a second inductor, a first switch, and a second switch convert the AC input voltage, rectify the AC input voltage, and output an intermediate DC voltage. The power factor control circuit receives the AC input voltage and receives the intermediate DC voltage. The power factor control circuit regulates the DC output voltage. Based on the AC input voltage and the intermediate DC output voltage, the power factor control circuit controls an inductor current waveform by driving the first switch and the second switch to create a substantially sinusoidal current as seen by the power source that is in phase with the AC input voltage.

Abstract: A universal input voltage device is presented which may receive a wide range of regulated and unregulated input voltages, both DC and a wide range of variable frequency AC, and output a desired regulated current at a desired voltage independent of the fluctuation of input voltage and frequency. The circuit includes a preconditioning input circuit, a Buck converter circuit with over voltage protection, flyback and boost circuits, and a shutdown circuit configured to drive a predetermined electrical or electronic device.

Abstract: The invention relates to an inverter for converting a DC voltage into an AC voltage having one or more phases, comprising an intermediate DC circuit having a first and a second DC capacitor unit connected in series between a first and a second terminal of the intermediate DC circuit, and a common earth terminal of the intermediate circuit, and at least one subcircuit for generating one phase of the alternating voltage, each subcircuit comprising: a first and a second auxiliary switch, each with a diode connected in parallel, an AC node for supplying a pulsed voltage, the first and second auxiliary switches being connected in series between the common earth terminal of the intermediate circuit and the AC node and the diodes of said power switches being connected to each other with opposite forward directions, and each of the subcircuits comprises two power switches, each with a diode connected in parallel, wherein said two power switches are connected in series between the first and second terminal o

Abstract: Methods for power factor correction (PFC) and for reducing conduction losses and switching losses in a power converter as well as the power converter and phase management circuitry for the power converter. The power converter includes a first PFC pre-regulator interleaved with at least one additional PFC pre-regulator, and a step down converter. The average input power is measured downstream of the front end at the step down converter and the average current sense signal is compared to a reference voltage. Each additional PFC pre-regulator is disable when output power generated by the front end is less than a first pre-designated rated power level and each additional PFC pre-regulator is enabled when the output power is greater than a second pre-designated rated power level.

Abstract: An adaptable electrical braking system for an electrical propulsion system of a traction vehicle is provided. The electrical braking system is configured to dissipate electrical energy in a plurality of resistor grids. The braking system includes a braking system assembly including a baseline chopper circuit topology. The baseline chopper circuit topology includes a first semiconductor-based circuitry in an enclosure for accommodating the first semiconductor-based circuitry. The braking system further includes a second semiconductor-based circuitry electrically coupled to the first semiconductor-based circuitry to produce a chopper including a chopper circuit topology fully contained in the enclosure. The second semiconductor-based circuitry includes a circuit topology selectable to adapt the baseline chopper circuit topology to meet distinct operational requirements to be fulfilled by the braking system.

Abstract: The invention relates to a vacuum plasma generator for providing a plasma discharge (10) for treating work pieces (5) by way of a pulsed plasma process in a vacuum chamber (2). Said vacuum plasma generator comprises a generator output (9, 9?) having an AC mains supply (6a), an AC/DC mains rectifier system (6) for rectifying the AC mains voltage to a DC voltage, a filter capacitor (6b), a first stage as clocked DC/DC voltage converter (7) with means for adjusting the DC output voltage which produces an intermediate circuit voltage (Uz), comprising a controlled power switch (7a) which feeds the primary winding of a transformer (14) and the secondary winding of which is connected to a rectifier (15) and a downstream intermediate capacitor (12) and configures a floating transformer secondary circuit (23). Said secondary circuit is connected to a downstream second stage which is a pulse output stage (8) and is connected to the generator output (9, 9?).

Abstract: The invention provides a control apparatus of a power conversion system for driving an induction motor via a VVVF inverter, wherein the AC voltage generated by the inverter is increased so as to expand the high-speed side property of the induction motor, to thereby improve the performance during power running and regenerative braking. In the present system, a DC power supply source having a power storage system with a capacity capable of processing the current flowing into or out of the inverter is inserted in series to the ground side of the input of the inverter, and the output voltage thereof is controlled from zero in a continuous manner to be added to the trolley voltage, which is then applied to the inverter.

Abstract: In a circuit apparatus for transformerless conversion of an electric direct voltage of a two-pole direct voltage source (1) connected to ground having a first voltage pole (+) and a second voltage pole (?) into an alternating voltage, hazardous capacitive leakage currents are avoided by connecting the direct voltage source (1) to ground and the DC-AC converter (400) is operated at a controlled intermediate circuit voltage, a DC-DC converter stage (300) being connected between the direct voltage source (1) and the DC-AC converter (400), said DC-DC converter stage providing at its output a +/? voltage that is symmetrical with respect to the grounding point, two series-connected capacitors (41, 42) having the same polarity and being connected to ground at their connecting point (V) and controlled are charged by two buck-boost choppers (100, 200) connected one behind the other.

Abstract: A regulating apparatus for a three-phase AC machine has a DC controller and an inverter. An input of the inverter is coupled to the DC controller and an output of the inverter can be coupled to the AC machine.

Abstract: In order to reduce the cost of a chopping converter supplying a continuous voltage at the terminals of a load (Z), a circuit with three windings (Lp, Ls1, Ls2) and a single magnetic core is proposed, according to the present invention, which enables the cost and the size of the circuit to be reduced. It is then necessary to add two diodes (D3, D4) to the circuit, but these elements are of low cost and of low size.

Abstract: In order to reduce the cost of a chopping converter supplying a continuous voltage at the terminals of a load (Z), a circuit with two windings (Lp, Ls) and a single magnetic core is proposed, according to the present invention, which enables the cost and the size of the circuit to be reduced. It is then necessary to add two diodes (D3, D4) to the circuit, but these elements are inexpensive and of small size.

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: An electrical power control apparatus and method for power factor correction in a conventional 60 hertz or other conventional frequency electrical AC power supply communicated to an inductive load. A plurality of interruptions of current in the line on both sides of an AC current oscillation, are created to control the power factor in a circuit energizing an inductive load. Additional power factor control and correction is provided by grounding of the line during each interruption. A controller controls the length and duration of each interruption based on preprogramming or input regarding current phase read or calculated in the line.

Abstract: A bi-directional boost circuit for power factor correction includes a power factor control circuit and a pair of diodes, a pair of inductors, and a pair of switches. A first diode, a second diode, a first inductor, a second inductor, a first switch, and a second switch convert the AC input voltage, rectify the AC input voltage, and output an intermediate DC voltage. The power factor control circuit receives the AC input voltage and receives the intermediate DC voltage. The power factor control circuit regulates the DC output voltage. Based on the AC input voltage and the intermediate DC output voltage, the power factor control circuit controls an inductor current waveform by driving the first switch and the second switch to create a substantially sinusoidal current as seen by the power source that is in phase with the AC input voltage.

Abstract: The invention focuses on a voltage transformer (VT) that includes at least two transformer stages (VT I, VT II), each of them with an input connection and to each of which an input subvoltage UEI, UEII is attached and added together they form an input voltage UE, and each of them with an outlet connection where an output subvoltage UAI, UAII is attached to each outlet, the total forming an output voltage UA. In order to prove that a concentration of electrical power of several stages is possible with or without a transformer, as well as to improve the efficiency and lower the cost, it is planned to attach a positive output subvoltage UAI at the first outlet of the transformer stage (VT I) with reference to a ground potential (P) and to attach a negative output subvoltage UAII with reference to this ground potential (P) at the outlet of the second transformer stage (VT II), whereby the sum of the individual output subvoltages UAI, UAII is the output voltage UA.

Abstract: A three phase buck power converter having input power control is described. The power converter uses a three input buck converter comprising switches for each phase, a catch rectifier, an inductor and an output capacitor. The duty cycle of the three switches is constrained to have a sine function relationship that may be derived from the input voltage wave form or from a reference oscillator. When so constrained, the input currents have high power factor. The output is a precise, high quality dc voltage, comparable to the output of a dc—dc buck converter, and the dynamic response is comparable. Voltage mode and current mode controls are shown, as is a precise line regulation feed forward for the voltage mode embodiment. The three phase buck power converter may be operated in reverse as a three phase boost converter, as they are reciprocal. A three phase ac—ac converter may have a three phase buck converter as its input and a three phase boost converter as its output.

Abstract: A power supply apparatus includes first and second switching elements respectively controlled by first and second clock signals, a first parallel resonance circuit connected between the first switching element and a dc power supply, a second parallel resonance circuit connected between the second switching element and the dc power supply, and a series resonance circuit connected between the first and second parallel resonance circuits. An output voltage of the power supply circuit is obtained from a node in the series resonance circuit.

Abstract: The invention relates to a series chopper comprising: a pair of input terminals A and B for connecting a DC input voltage Vin, a pair P of breakers SB, ST in series connected by the breaker SB to the input terminal B, ST comprising a control input Cm1 for setting ST either into an on state or into an isolated state, SB comprising a control input Cm2 for setting SB either into an on state or into an isolated state, a pair of output terminals C and D, for supplying, with an output voltage Vout, a load R the output terminal D being connected to the input terminal B and the output terminal C to the point of connection between the two breakers SB and ST in series across an inductor. The series chopper comprises K other additional pairs Pi of breakers in series between the input terminal A and the free side of the breaker ST with i=1, 2 . . . K. K input capacitors Cfi in series connected to the K pairs of breakers with i=1, 2 . . . K, . . .

Abstract: There are disclosed a synchronous rectifying type of DC—DC converter, a DC—DC converter control circuit constituting such a type of DC—DC converter, a monitor circuit for monitoring an operation of a DC—DC converter, and an electronic equipment having a DC—DC converter, considering a conduction current. A DC—DC converter has a main switch and a synchronous rectifying switch, in which said main switch and said synchronous rectifying switch are alternately turned on so that a voltage of a DC electric power is transformed and outputted. A state that said main switch and said synchronous rectifying switch are simultaneously turned on is detected.

Abstract: Device for reversible conversion of electric power capable of being connected between at least an input alternating voltage source and at least a load forming an output alternating current source, each input alternating voltage source having a supply terminal and a neutral terminal. The device comprises at least a switching block and includes an input terminal for connecting the supply terminal, a single reference terminal and an output terminal. Each switching block consists of a switching matrix formed of capacitors and switching cells, individually controlled. Each reference terminal is connected to a reference point other than the neutral terminal, and each block comprises elements for permanently maintaining at a constant or null sign the difference of potential between the first input terminal and the reference terminal.

Abstract: A cutting device for reversibly converting electric power between an alternating voltage source and an alternative current source, comprises switching cells each comprising first and second switches unidirectional in voltage and bidirectional in current. A first group of switches consists of the first switches of the switching cells connected in series between a first terminal of the voltage source and a first terminal of the current source, and a second group of switches consists of the second switches of the switching cells connected in series beween a second terminal of the voltage source and the first terminal of the current source, the unidirectional characteristics in voltage of the first and second switches belonging to a first half of the cells being respectively opposed to those of the first and second switches belonging to a second half of the cells.

Abstract: A piezoelectric ceramic light starter, which includes a power switch, a piezoelectric transformer, and a frequency tracking unit, is disclosed. The power switch connected to a pulse width modulated (PWM) harmonic signal output terminal closes when the PWM harmonic signal is in its positive period, and opens when which signal is in negative period. The piezoelectric transformer has the input terminal of its first-level coil connected to the power switch. The output terminal of the first-level coil generates a high-frequency AC signal to drive a cold cathode fluorescent light (CCFL). The frequency tracking unit is coupled to the output terminal of the CCFL. When the light starter starts, a first frequency is obtained when the CCFL is lighted and a second frequency is obtained when the CCFL is turned off. The PWM harmonic signal uses the average of the first frequency and the second frequency as the basis for output.

Abstract: Device for reversible conversion of electric power capable of being connected between at least an input alternating voltage source and at least a load forming an output alternating current source, each input alternating voltage source having a supply terminal and a neutral terminal. The device comprises at least a switching block and includes an input terminal for connecting the supply terminal, a single reference terminal and an output terminal. Each switching block consists of a switching matrix formed of capacitors and switching cells, individually controlled. Each reference terminal is connected to a reference point other than the neutral terminal, and each block comprises elements for permanently maintaining at a constant or null sign the difference of potential between the first input terminal and the reference terminal.

Abstract: A programmable motor controller for receiving three-phase input power at an input power frequency and having a polarity is presented. The controller includes a primary chopper for reversing each phase of electrical power according to a reference frequency. Each primary chopper has a power input, a signal input, and an output. The power input is electrically connected in wye connection to each phase of power. A transformer for each phase of power has primary and secondary terminals and is connected electrically by its primary terminals to the output of the primary chopper. A secondary chopper for each phase of power is configured to reverse each phase or electrical power according to the reference frequency and phase shifted according to a second reference signal. The secondary chopper has an input connected electrically to the secondary terminals of the transformer in an output connected to a winding of a motor.

Abstract: A direct conversion programmable power controller receiving polyphase input power at an input power frequency and with a polarity is provided. The controller includes a primary chopper for reversing each phase of electrical power according to a reference frequency that is substantially higher than frequency of the electrical power. Each primary chopper has a power input, a signal input, and an output. The power input is electrically connected in wye-connection to each phase of power. A transformer for each phase of power has primary and secondary terminals and is electrically connected by its primary terminals to the output of the primary chopper. A secondary chopper for each phase of power has an input connected electrically to the secondary terminals of the transformer. The secondary chopper is configured to reverse each phase of electrical power according to the reference frequency and to shift phases of electrical power according to a reference signal.