Abstract: The invention relates to a converter circuit comprising at least one phase module (100) having an upper and a lower converter valve (T1, . . . , T6), wherein each converter valve (TI, . . . , T6) has at least one two-pole subsystem. According to the invention, each two-pole subsystem (14) has four semiconductor switches (21, 23, 25, 27), which can be switched off and are connected electrically in series, four diodes (22, 24, 26, 28), which are each connected electrically back-to-back in parallel with one semiconductor switch (21, 23, 25, 27) which can be switched off, two unipolar storage capacitors (29, 30), which are connected electrically in series and in parallel with the series circuit comprising the semiconductor switches (21, 23, 25, 27), and an electronic system (32), whose reference potential connection (M) is electrically conductively connected to a common potential (P0).

Abstract: A plurality of half-wave bridge type oscillators are operated in a time-sharing method and connected through primary windings of a transformer to make the reverse bias hold time of each thyristor long. Therefore, it is possible to stably output a frequency and power which are several times as high as those in a conventional power supply.

Abstract: In a method for measuring motor speed and position by detecting the back-EMF generated during pole-pair interactions, fluctuations of a three-phase motor power supply that may affect back-EMF detection are reduced. One phase of the power supply is tristated for a certain interval preceding and during back-EMF detection. For a shorter interval during back-EMF detection, the voltage drop across the motor is reduced from the full power supply voltage. This preferably is accomplished either by pulling a first of the other two power supply phases low, while pulling a second of the other two power supply phases up to a regulated voltage below the power supply voltage, or by pulling the second of the other two phases up to the power supply voltage and pulling the first of the other two phases down to a regulated voltage above ground.

Abstract: A power conversion apparatus is formed by connecting unit communication-assisting means in series between an alternating-current terminal incorporated in a conventional current-type power conversion apparatus, and an alternating-current load. The communication-assisting means includes reverse-blocking-type self-commutated devices and a capacitor. By controlling the switching of the reverse-blocking-type self-commutated devices, a voltage is generated at the capacitor and additionally used for a power supply commutation operation or load commutation operation. By virtue of this structure, the power conversion apparatus can easily provide a large capacity (high voltage, large current), and can be improved in power factor. Further, the structure enables the number of required fundamental elements to be reduced, and hence enables the power conversion apparatus to be produced easily at low cost.

Abstract: A method and an apparatus for charging a filtering capacitor in the direct-voltage intermediate circuit of a voltage-controlled PWM frequency converter comprising a rectifier (20) connected to an alternating-current source (UR, US, UT), a direct-voltage intermediate circuit and an inverter unit (11)/inverter units for feeding a multi-phase alternating voltage (UU, UV, UW) of variable frequency into a load/loads (12), said rectifier bridge having controlled semiconductor switches (V1–V3), especially thyristors, in one arm, preferably in the upper arm, and diodes (D1–D6) in the other arm, preferably the lower arm, and said direct-voltage intermediate circuit being provided with a capacitor unit (CDC) of a relatively high capacitance for filtering the voltage.

Abstract: An electrical drive apparatus, in particular, a motor-driven motor vehicle window winder or motor vehicle belt roller, which can be operated via a full bridge circuit with at least four switching elements with a different load depending on the rotation direction, wherein the switching elements are individually designed on the basis of their different maximum loads, in the sense of an asymmetric full bridge.

Abstract: A converter circuit arrangement is disclosed for matching a variable DC voltage to a drive circuit for producing drive signals and having a three-point DC voltage intermediate circuit (2), which three-point DC voltage intermediate circuit (2) is formed by a first capacitor (3) and a second capacitor (4) connected in series with it, with one connection of the first capacitor (3) forming an upper connection (5) of the three-point DC voltage intermediate circuit (2), and the first capacitor (3) forming a center point connection (6) at the junction point with the second capacitor (4) and one connection of the second capacitor (4) forming a lower connection (7) of the three-point DC voltage intermediate circuit (2).

Abstract: An H-type motor bridge coil driver circuit is implemented with an electronic switch in each leg segment of an H-shaped circuit, this bridge circuit having its side legs each connected between a power supply and ground, with the inductive load of a motor coil being connectable as the cross leg of the H-shaped circuit. An alternate current path, voltage level stabilizing element may be connected across each leg segment electronic switch. A coil excess energy storage element may be connected to the coil nodes of the circuit, through alternate current path elements and utilized to temporarily store the discharging of the excess coil energy normally available because of the lagging nature of the motor coil current. This temporary storage element then may discharge this energy back to the power supply through a passive circuit element, and reverse polarity protection is included for the power supply.

Abstract: A fault current tolerant power supply circuit having a dc power source and switching devices for inverting dc current from the source into ac load current includes a protective circuit for protecting the switching devices from overvoltage conditions when an inductive load is short-circuited. The protective circuit uses a capacitive component to absorb charge during a short circuit to protect non-conducting switching devices from an overvoltage condition.

Abstract: A current source inverter (1) comprises a bridge circuit (2) having a plurality of bridge paths (5), in each of which a controllable power semiconductor component (6) is arranged. In the case of such an inverter, a loss in performance on account of inductance-dictated overvoltages during the turn-off of the power semiconductor components (6) is avoided by virtue of the fact that the controllable power semiconductor component (6) is avalanche-proof at least under loading in the forward direction.

Abstract: The invention concerns a device for powering an ozonizer (7), characterized in that it includes a direct current power source (8), at the terminals of which are connected a dual series converter bridge coupled with a resonant charge consisting of a high voltage inductance (14) series-connected with the ozonizer (7).

Abstract: An inverter having a large-capacity self-arc-extinguishing semiconductor element. Recovery capacitors recover energy stored in groups of elements for suppressing the rate of change in current, and are provided within a two-level or three-level inverter bridge. The thus-recovered energy is fed back to a d.c. voltage circuit by an energy regenerative circuit. The energy regenerative circuit controls the charging voltage of the recovery capacitors in proportion to the magnitude of a load current. In a case where the inverter includes inverter bridges connected to a single d.c. voltage circuit, the inverter bridges are divided into groups. A different energy regenerative circuit is connected to the inverter bridge on a per-group basis, and each of the energy regenerative circuits feeds power back to the d.c. voltage circuit.

Abstract: A high voltage inverter cascades a plurality of multiple voltage level inverter modules each fed by an isolated dc energy unit to reduce the number of stages of the inverter required to generate a desired ac voltage. Thus, where the dc energy unit includes the secondary winding of an ac transformer, the number of each winding needed is reduced. By using active rectifiers operated in a boost mode to convert the transformer secondary voltage to dc for powering the inverter modules, regenerative operation can be achieved.

Abstract: A power converter having two main switches connecting an outlet either to a positive rail or to a negative rail, two free-wheel diodes enabling the current through the load to be maintained, two snubber capacitors, and an auxiliary circuit. The auxiliary circuit includes an auxiliary inductor in series with two auxiliary switches coupled between the outlet and a midpoint of a capacitive voltage divider that provides a midpoint voltage. A detector detects current oscillation between the auxiliary inductor and the snubber capacitors, and then switches off the oscillation current and allows the intended main switch to conduct in response to the interruption.

Abstract: A fault tolerant power supply circuit for a series resonant load having an inductive impedance. The power supply circuit includes alternately conducting first and second sets of switches for supplying current to the load in alternating directions. One terminal of the load is connected to a point intermediate the switches. A protective coil is connected in series with the load and the point intermediate said switches. In one embodiment of the invention, a di/dt reactor is connected in series between the switches. In that embodiment, one end of the protective coil is connected to the load and the other end of the protective coil is connected to the di/dt reactor at a point intermediate the switches.

Abstract: A converter is specified which is distinguished in that a bus system is provided between the paths of a phase module of the converter and allows potential chambers to be formed around the semiconductor switches and/or the circuitry elements. The potential chambers surround the semiconductor switches and the circuitry elements. They comprise two longitudinal metal sheets which are arranged to be insulated from one another, in particular overlapping. In addition, transverse metal sheets may be provided, which are connected to the connections of the semiconductor switches and/or circuitry elements. The potential chambers result in each potential chamber having a potential difference which is only a fraction of the intermediate circuit voltage. The bus system carries out the insulation of the high potential difference corresponding to the intermediate circuit voltage.

Abstract: A converter circuit arrangement is specified. An extremely compact structure is achieved by virtue of the fact that the current rise limiting inductor concentrically surrounds the second stack containing diode and resistor. In particular, the inductor can be designed as a wire helix surrounding the stack. A very compact structure of the converter is produced, furthermore, by virtue of the fact that the first and second stacks, that is to say the stack of the switches and the stack of the snubber, belong to a common clamping lattice.

Abstract: A three-level NPC converter includes at least one phase leg including four series coupled electrical switches having a first pair junction between the first two switches and a second pair junction between the second two switches. First and second inner switch snubber capacitors are coupled in series at a neutral junction. First and second inner switch snubber diodes are respectively coupled to the first and second pair junctions and respectively coupled at first and second inner diode-capacitor junctions to the first and second inner switch snubber capacitors. First and second inner switch snubber resistors are respectively coupled between the first and second inner diode-capacitor junctions and respective portions of a DC bus. In one embodiment, the NPC converter further includes first and second outer switch snubber diodes coupled between respective first and second inner diode-capacitor junctions and respective portions of the DC bus.

Abstract: A low-loss power inverter is provided. Each inverter phase includes an upper and a lower bridge half, each having two power semiconductor switches, with antiparallel-connected diodes, with one tie point of the power semiconductor switches being connected using an isolating diode to a tie point of a d.c. intermediate circuit, an auxiliary circuit consisting of an upper and a lower auxiliary switch and a resonant inductor is provided, and at least one resonant capacitor is provided for power semiconductor switches of the inverter phase. This yields a low-loss power inverter which combines the advantages of a three-point inverter with those of an ARCP inverter.

Abstract: In a method for the drive of a number of coupled output stages drive signals for the output stages are generated. Given an over-voltage condition in one of the output stages, the output stage affected by the over-voltage condition is switched into a charge output mode for a limited time duration and at least one other output stage is switched into a charge pick-up mode for a limited time. This method is utilized in the operation of a control module and of a power amplifier, and achieves a charge compensation or balancing or equalization between the output stages with very little circuit-oriented outlay.

Abstract: A portable power unit is provided. A desired waveform signal indicative of a desired waveform having a desired frequency is generated. Switching control of a variable control bridge circuit is performed based on the desired waveform signal to cause the variable control bridge circuit to generate an alternating current output. A waveform of the alternating current output is detected to generate an output waveform signal indicative of the detected waveform of the alternating current output. A power factor is detected by comparing the desired waveform signal and the output waveform signal to generate a power factor signal indicative of the detected power factor. Voltage of the alternating current output is controlled based on the power factor signal.

Abstract: A novel solar inverter circuit is used to connect a solar photovoltaic (PV) array with an alternating current (AC) voltage source to convert direct current (DC) power from the PV array to AC power. The solar inverter circuit employs the current-voltage (I-V) characteristic of the PV or solar cell, and an H-Bridge circuit with gate controller. The gate controller synchronizes the H-bridge with the AC voltage source. The PV array and the solar inverter circuit can plug directly into a residential AC plug and provides electrical power as a supplementary AC supply. Electrical energy required by the home appliances is supplied by the municipal AC line and solar energy concurrently. Advantages of the solar inverter circuit of the present invention include the flexibility of using the solar inverter circuit with any number of solar cell panels through the implementation of an impedance transformer, and the implementation of an additional, optional output for DC battery charging.

Abstract: An AC current source circuit converts a DC input voltage into an AC output current, and comprises a chopper circuit for converting a DC input voltage into a chopper voltage; and an inverter for converting the chopper voltage into an output AC current of a predetermined frequency. The inverter comprises at least four switch elements, and clamp-type snubber circuits corresponding to each of the switch elements are provided. The snubber circuit releases electric charges to the input terminal of the DC input voltage of the chopper circuit. The chopper circuit is connected to the inverter through a DC reactor. The DC input voltage is converted into a DC current by the chopper circuit and the DC reactor and transmitted to the inverter.

Abstract: A power converting apparatus includes a power converter connected to a power line via a transformer 3, and current detectors 5A and 5B for detecting the currents of the windings of the transformer. The output signals of the current detectors 5A and 5B are mathematically processed to produce an exciting current component of a transformer 3. The exciting current component is mathematically processed to produce a flux density contained DC component. Further, the flux density contained DC component and a flux density contained DC component command value are mathematically processed to produce a voltage command correction value.

Abstract: The power converter extracts the accumulated energy accumulated in a snubber capacitor (a first capacitor) from the second capacitor in a series circuit, composed of a second capacitor and a diode, which is provided in parallel with that snubber capacitor, and uses it as the driving power source for a self-turn-off-semiconductor device.

Abstract: The MOSFETs or IGBTs of respective arms of an electronic inverter are in series with SCRs or TRIACs triggered into conduction during intervals of intended conduction of the respective MOSFETs or IGBTs connected to the high level rectifier terminal. The piloting of the SCRs or TRIACs is effected from the piloting of the MOSFETs or with delay or in a conditional manner. The circuit eliminates the effective transience on the inverter output.

Abstract: A circuit for powering a two-phase AC induction motor. The circuit generates a first signal of the form Vdc+A sin(2.pi.ft-0.degree.) and a second signal of the form Vdc+A sin(2.pi.ft-90.degree.). The first signal is input to a first error amplifier along with a first sampled difference signal from the motor. The second signal is input to a second error amplifier along with a second sampled difference signal from the motor. The outputs from each of the first and second amplifiers is input into a first comparator and a second comparator along with a sawtooth waveform to create a first sinusoidally modulated square wave signal and a second sinusoidally modulated square wave signal. The first and second sinusoidally modulated square wave signals are fed to driver circuits which in turn control an H-bridge circuit for powering the motor from a DC bus.

Abstract: A power supply for generating an uninterruptible AC power signal. The power supply utilizes leakage inductance in its transformer to eliminate the need for an output inductor. In standby mode, the AC power signal is generated from a battery by a switching circuit. Certain components of the switching circuit are also used to charge the battery when the power supply is operating in line mode.

Abstract: The accident detection circuit of the present invention is such that in a voltage-type self-excited power converter composed of anode reactors 13 and 23 connected in series, respectively, to power semiconductor elements 11 and 21 of self turn off type connected in series, there are provided anode reactor voltage direction-detecting circuits 16 and 26 which detect, respectively, that the voltage in the direction generated in the anode reactors 13 and 23 exceeds a predetermined value when the current flowing in the direction of from the anode to the cathode of the each element 11, 21 increases, anode current direction-detecting circuits 17 and 27 which detect, respectively, that the current flows in the direction of from the anode to the cathode of the each element 11, 21, delay circuits 18 and 28 which delay, respectively, the output signal of each arm current direction-detecting circuit by a certain period of time, and AND circuits 19 and 29 which designate the output signal of the each anode reactor voltage

Abstract: A gate drive circuit for a voltage-driven type power switching device, including a control device for generating a gate voltage for the voltage-driven type power switching device, and a correction device connected to the control device for receiving the gate voltage and for correcting an effect of a magnetic flux resulted from a main circuit current flowing in the voltage-driven type power switching device applied to the gate voltage to generate a corrected gate voltage. The corrected gate voltage is applied to a gate of the voltage-driven type power switching device.

Abstract: The apparatus for non-contacting feeding of a high frequency power according to the present invention comprises a double voltage full-wave rectifier circuit which converts an AC input into a DC output, Royer oscillation circuit consisting of FETs and which receives the DC output from the voltage double full-wave rectifier circuit and provides a high frequency oscillation, the gate windings ofhe FETs being the second winding of a saturable circuit, a starting gate bias stabilization circuit for the Royer oscillation circuit, and a main transformer which delivers a high frequency power produced in the Royer oscillation circuit, through the primary winding of the oscillation-use saturable transformer.

Abstract: A procedure and an apparatus for converting a first alternating voltage into a second alternating voltage with respect to frequency and amplitude by means of first (1) and second (2) bridges having switches (T.sub.1 . . . T.sub.12), and a resonant circuit (3) connected between the bridges. The invention also relates to the use of a frequency converter for the control of a motor. The voltages of a supplying network and the voltages of a load (M) are connected across the resonant circuit (3) in an alternating fashion by means of bridge switches (T.sub.1 . . . T.sub.6) and bridge switches (T.sub.7 . . . T.sub.12), respectively. The voltages are alternately connected across the resonant circuit for a period equal to respective half cycles of the characteristic frequency of the resulting resonant circuit formed. When power is supplied, a bridge change is effected after each period.

Abstract: A multi-resonant circuit has a series-resonant circuit coupled to the input of an inverter. The output of the inverter is coupled to a parallel resonant circuit. The output of the parallel resonant circuit energizes a load, which could be gas discharge lamps. The operating frequency of the inverter is between the resonant frequency of the series resonant circuit and the resonant frequency of the parallel resonant circuit.

Abstract: A method for controlling current converter valves of a load-guided parallel oscillator inverter of an induction furnace includes supplying the inverter from a direct current source having positive and negative poles, and adjusting a current flow from the direct current source across the parallel oscillator by firing two diagonally opposed current converter valves of the inverter at a time. The method of the invention includes firing the two diagonally opposed current converter valves at a time with a delay between them for intermittently producing a short circuit current from the positive pole of the direct current source to the negative pole of the direct current source through two of the current converter valves being directly series-connected.

Abstract: The invention relates to a series-resonant converter circuit, which includes a capacitive energy storage network coupled to an inductive energy storage network for supplying a load. A current switching network comprising a pair of controlled switches is provided for switching the converter circuit between discrete successive cycles. Voltage clamping means, such as a pair of clamping diodes, are used to control the magnitude and polarity of the voltage across the capacitive energy storage network. A freewheel inductance is arranged to supply freewheel current for allowing zero voltage switching of the controlled switches at a switching frequency which is less than the resonant frequency of the resonant tank.

Abstract: A relatively small and compact high voltage, high current power supply for a laser utilizes a plurality of modules containing series resonant half bridge inverters. A pair of reverse conducting thyristors are incorporated in each series resonant inverter module such that the series resonant inverter modules are sequentially activated in phases 360.degree./n apart, where n=number of modules for n>2. Selective activation of the modules allows precise output control reducing ripple and improving efficiency. Each series resonant half bridge inverter module includes a transformer which has a cooling manifold for actively circulating a coolant such as water, to cool the transformer core as well as selected circuit elements. Conductors connecting and forming various circuit components comprise hollow, electrically conductive tubes such as copper. Coolant circulates through the tubes to remove heat. The conductive tubes act as electrically conductive lines for connecting various components of the power supply.

Abstract: An electric power converter comprising a plurality of reactors, a plurality of self quenching type switching elements, the reactors and switching elements being series-connected per one arm, and surge-absorbing snubber circuits connected in parallel to the switching elements respectively, the switching circuits being driven by gate drive circuits connected to respective gates of the switching elements to thereby convert a DC voltage into an AC voltage or convert an AC voltage into a DC voltage. The electric power converter further comprises: an apparatus for recovering energy accumulated on at least one side of the reactors and the snubber circuits and an apparatus for generating a DC source for supplying electric power to each of the gate drive circuits, on the basis of the recovered energy.

Abstract: In a multi-series inverter arrangement comprising a DC circuit including a neutral point output terminal and a multi-series inverter including three series connections of first through fourth GTOs, each connected in parallel with the DC circuit, the juncture of the first and second GTOs and the juncture of the third and fourth GTOs being connected to the neutral point output terminal via respective clamping diodes and the first and third GTOs and the second and fourth GTOs being on and off controlled each other in a conjugate relationship, individual gate driving circuits for the second and third GTOs being designed to provide a larger gate current, in particular, a larger wide width gate forward current to the corresponding GTOs than that provided by individual gate driving circuits for the first and fourth GTOs to the corresponding GTOs.

Abstract: An electrical power converter having a phase converter constituted by positive side semiconductor switching elements connected in series and negative side semiconductor switching elements connected in series which converts a DC voltage to an AC output phase voltage having at least three potential levels, resulting in three possible modulation modes: dipolar, partial dipolar and unipolar. Dipolar modulation is realized by alternating positive and negative output pulses. Unipolar modulation is realized by output pulses having only the same polarity as the corresponding fundamental modulation wave. Transition is accomplished via partial dipolar modulation which is realized by alternating positive and negative output pulses in a first period of a half cycle by outputting alternating positive and negative pulses and in a second period by outputting pulses having only the same polarity as the corresponding fundamental modulation wave.

Abstract: A conversion apparatus including a plurality of high-speed switching devices, each being operable in latch type operation and non-latch type operation and a power source for supplying a first current to the high-speed switching devices, thereby forming a current path of the high-speed switching devices. The high-speed switching device is turned off after changeover from the latch type operation to the non-latch type operation. The conversion apparatus further includes a current regulation circuit provided in the current path for regulating a second current flowing through the current regulation circuit after the second current has reached a prescribed value. In case of overcurrent malfunction, the high-speed switching device is changed from the latch type operation to the non-latch type operation, and then is caused to be turned off while the current regulation circuit regulates the second current.

Abstract: A power inverter control device is designed to control a neutral point clamped power inverter apparatus including first to fourth self-extinction elements sequentially connected in series between two end terminals of a power supply having an intermediate terminal, four freewheeling diodes connected in parallel with the self-extinction elements in a direction opposite thereto, a series circuit of first and second clamping diodes, connected in parallel with a series circuit of the second and third self-extinction elements in a direction opposite thereto and having a node connected to the intermediate terminal of the power supply.

Abstract: An arrangement monitors a consumer in combination with an internal combustion engine or motor vehicle especially for monitoring an electric drive which is driven by an output stage in the form of a bridge circuit. Potentials are compared in the area of the consumer or of the output stage to pregiven threshold values derived from the normal operation. From this comparison, an alarm signal is generated in a time-delayed manner with the time delay being dependent upon the magnitude of the drive signal.

Abstract: This invention consists of a power conversion device wherein a circuit comprising semiconductor power elements and fuses connected in series with these, and feedback diodes connected in antiparallel with said semiconductor power elements is connected as a bridge, the A.C. terminals of said bridge circuit are connected to an A.C. power source, and the D.C. terminals are connected to a D.C. power source provided with a capacitor, characterized in that said feedback diodes are connected in antiparallel with the series circuits of said semiconductor power elements and fuses.By means of the layout described above, the fuses are prevented from melting when a D.C. short-circuit occurs, since the current that flows from the A.C. terminal to the D.C. power source on D.C. short-circuiting flows through a feedback diode or a bypass diode, and not to the fuses.

Abstract: In a control apparatus for controlling the firing timing of each of thyristor valves constituting a thryistor bridge by use of at least two series of control systems, a bypass-pair control circuit for thyristor bridge includes a circuit for detecting the conduction states of the thyristor valves, and a circuit for determining a conductive valve at the time of bypass-pair operation in accordance with a result of detection of the conduction state of each thyristor valve.

Abstract: In a quarter-bridge circuit for high currents the total current is subdivided into a plurality of parallel current paths. In each current path a semiconductor component (5.1, . . . , 5.n, 6.1, . . . , 6.n) that can be turned off via a gate, a freewheeling diode (7.1, . . . , 7.n, 8.1, . . . , 8.n) located opposite a midpoint, and a clamping capacitor (9.1, . . . , 9.n, 10.1, . . . , 10.n) are arranged in parallel with the freewheeling diode (7.1, . . . 7.n, 8.1, . . . , 8.n) and the turnoff semiconductor component (9.1, . . . , 9.n, 10.1, . . . , 10.n) in such a way that the respective freewheeling path has as minimal an inductance as possible. Provided between a load terminal (3) of the quarter-bridge circuit and each midpoint of a current path is one inductor (L11.1, . . . , L11.n, L21., . . . , L21.n) each which limits the rate of current rise, so that a current rush caused by an operating delay does not overload the turnoff semiconductor component (9.1, . . . , 9.n, 10.1, . . . , 10.n).

Abstract: A series resonant circuit and at least two push-pull connected electronic switches are traversed by a respective halfwave of the resonant-circuit current and via which switches the series resonant circuit is coupled to a d.c. source. GTO thyristors form the electronic switches, which thyristors are switched by a pulse generator device which generates a blocking pulse at the zero crossing of the resonant-circuit current and which generates a trigger pulse for the subsequently conductive GTO thyristor a predetermined delay time after activation of the blocking pulse to selectively shape the output current of the inverter to control the resultant power.

Abstract: A series resonant circuit is coupled to a direct voltage source via two push-pull connected thyristors and diodes connected inverse-parallel there across. A zero-crossing detector generates a zero-crossing signal as soon as the thyristor ignition pulse current through the series resonant circuit drops below a given value after its zero crossing, and an ignition pulse generator which is controlled by the zero-crossing detector generates ignition pulses for the thyristors. To prevent unintended interruption of the inverter operation, a measuring device measures the time interval between an ignition pulse and the subsequent zero-crossing signal, a memory stores the time interval for normal operation, and a circuit generates an auxiliary zero-crossing signal when the measured time interval exceeds the stored time interval by more than a predetermined value.

Abstract: A current source inverter power supply for an ozone generator which results in improved efficiency and reliability in operation of such generators has an AC/DC converter coupled through a large inductance to a DC/AC inverter that, in turn, is coupled at its output to the primary of a high voltage transformer. Such transformer has an air gap in its core to supply the electrical characteristics necessary for resonance with the load which is capacitive in nature. Thyristors in the inverter are naturally commutated so the switching frequency is close to, but slightly above, the natural resonant frequency of the inverter/transformer/ozone generator circuit.

Abstract: A power supply module for control electronics of a DC motor, the module comprising a power cell of the stepdown type controlled as a function of peak current, the current flowing in both directions, and the module including a bridge stage likewise capable of passing current in both directions and including a reactive element constituted by one of the windings of the DC motor. The invention is particularly suitable for space applications.

Abstract: A power converter for supplying an AC load with a sum of an output voltage of multiplexed PWM inverters each having an output transformer, and an output voltage from a direct-connection PWM inverter having no output transformer. One or a plurality of PWM inverters constituting the multiplexed PWM inverters comprise a circuit for controlling primary or exciting currents of corresponding output transformers connected thereto, and the direct-connection PWM inverter comprises a circuit for controlling a current to be supplied to the AC load.