Abstract: A vehicle includes a battery that is rechargeable using an external power source coupled to the vehicle. The vehicle includes a controller that is programmed to estimate parameters of the battery using a parameter estimation algorithm. The controller is programmed to change a charging current when connected to the external power source to provide an input to the parameter estimation algorithm that is sufficiently dynamic such that the parameter estimation algorithm converges to an accurate solution.

Abstract: Systems and methods for medical imaging. The method may include acquiring a tube voltage switching waveform for a radiation source of a medical device. The method may include determining a tube current switching period based on the tube voltage switching waveform. The method may include determining a sampling period correlated with the tube current switching period. The method may include acquiring projection data according to the sampling period. The method may further include reconstructing an image based on the acquired projection data.

Abstract: A system and a method for acquiring image data of a subject with an imaging system is provided. The system can include a gantry that completely annularly encompasses at least a portion of the subject, with a source positioned within and movable relative to the gantry. The source can be responsive to a signal to output at least one pulse. The system can include a detector positioned within and movable relative to the gantry to detect the pulse emitted by the source. The system can also include a detector control module that sets detector data based on the detected pulse, and an image acquisition control module that sets the signal for the source and receives the detector data. The image acquisition control module can reconstruct image data based on the detector data. The signal can include a signal for the source to output a single pulse or two pulses.

Abstract: An electric power converter includes a DC stabilization circuit configured to stabilize a DC voltage from DC power supply, and an inverter configured to convert the DC voltage stabilized by the DC stabilization circuit to an AC voltage. The DC stabilization circuit includes an aluminum electrolytic capacitor configured to smooth the DC voltage, a saturable reactor configured to prevent the DC stabilization circuit from oscillating, and a film capacitor configured to supply a ripple current to the inverter.

Abstract: In an AC link type boosting device, DC terminals of two voltage inverters are connected each other in series in additive polarity and plural AC terminals of each of the voltage inverters are connected to a transformer. The two voltage type inverters are AC linked to each other via the transformer. An external voltage applied between the DC terminals of the AC link type booster is divided by the voltage-type inverters.

Abstract: A switching mode power supply (SMPS) includes a power transistor coupled to the primary winding of transformer and a resistor coupled between the input power source and a control terminal of the power transistor for triggering a primary current flow through the power transistor for providing startup power. A primary side control circuit is configured to regulate the output of the SMPS. A secondary side control circuit is coupled to the secondary winding and being configured to provide a first electrical signal to the secondary winding when an output voltage of the SMPS is less than a first reference voltage, whereupon an awakening signal is induced in the auxiliary winding and causes the primary side control circuit to provide a turn-on signal to the power transistor. The primary side control circuit is configured to enter a standby mode or a normal operating mode in response to the awakening signal.

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: An inductor current flows through an inductor of a flyback converter. In a constant voltage mode, the pulse width of an inductor switch control signal is adjusted to maintain a constant output voltage of the flyback converter. The inductor switch control signal controls a switch through which the inductor current flows. In a constant current mode, a comparing circuit, a control loop and a clamp generator circuit are used to maintain the peak level of inductor current. The comparing circuit generates a timing signal based on the ramp-up rate of the inductor current. The control loop uses the timing signal and a feedback signal to generate a time error signal. The clamp generator circuit uses the time error signal to generate a clamp signal that adjusts the pulse width of the inductor switch control signal to clamp the peak current output by the flyback converter in the constant current mode.

Abstract: A control device for controlling a recovery from a locking of a motor includes: a switching unit which supplies a motor current from a current supplying unit to the motor; and a driving control unit which supplies a PWM control signal to the switching unit to control a driving of the switching unit. The driving control unit supplies the PWM control signal with a low duty ratio lower than a regular duty ratio to the switching unit when the locking of the motor is detected depending on a variation in temperature of the switching unit. The driving control unit supplies the PWM control signal with the regular duty ratio to the switching unit when a cancel of the locking of the motor is detected depending on a variation in inter-terminal voltage of the motor.

Abstract: Circuits and methods of suppressing signal glitches in an integrated circuit (IC). A glitch on a signal entering a clock buffer, for example, is prevented from propagating through the clock buffer. In some embodiments, a latch is added to an input clock path that detects a transition on the input signal, and then ignores any subsequent transitions for a time delta that is determined by a delay circuit. In some embodiments, a multiplexer circuit is used to select between the input clock signal and the output clock signal, with changes on the input clock signal not being passed through the multiplexer circuit unless the time delta has already elapsed. In some embodiments, the delay is programmable, pin-selectable, or self-adapting.

Abstract: For the purpose of providing a resonant switching power supply device having a wide output voltage variable range by changing its switching frequency, the resonance circuit thereof comprises a switching transformer, a first resonance section connected in series with the switching transformer, and a second resonance section connected in parallel with the switching transformer, wherein the resonance frequency characteristic in the case that the DC load current is large is formed using the series-connected devices of the first resonance section, and the resonance frequency characteristic in the case that the DC load current is small is formed using the first resonance section, the second resonance capacitor of the second resonance section and the switching transformer.

Abstract: Power supply sequencing systems and methods are disclosed. In one embodiment, a programmable charge pump supplies a programmable current source, which drives an external NFET that controls whether power is supplied to a device or a portion of circuitry. The maximum voltage and the turn-on ramp rate supplied to the NFET are programmable and, therefore, the NFET can be operated safely within its rated limits without requiring external protection devices. If a high-voltage output terminal is not required to drive an external NFET, the output terminal, in accordance with another embodiment, may be configured to function as an open drain logic output terminal.

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: To provide an IC chip for contactless IC card that ensures reliabilities such as data retention of nonvolatile memory and reduces power consumption. Power supply voltages VDD and VSS, which are output from a rectifier circuit, are used as a power supply for driving an analog circuit, digital circuit, and memory control circuit to cause them to operate at low voltages. A booster circuit is provided for generating a power supply voltage VDDM, which is a boost voltage, to drive a memory circuit. Because the memory circuit can be operated at the same, high voltage and the other circuits can be operated at lower voltages than voltages that would be used in a case where the analog circuit, digital circuit, memory control circuit and memory circuit are driven by a common power supply, power consumption can be reduced.

Abstract: A voltage converter circuit uses a silicon-controlled rectifier for converting input voltage to selected levels of output voltage. The silicon-controlled rectifier is connected in a circuit including a capacitor which oscillates between charging and discharging to produce a resulting waveform that is applied to a transformer for developing high positive and negative output voltages. Pulses are produced which are asynchronous with alternating line signal. Since the silicon-controlled rectifier operates on DC voltages, an electrolytic capacitor of high capacitance values can be connected between the silicon-controlled rectifier and AC or DC supply lines to substantially reduce noise signals conducted back into the supply line.

Abstract: In a two-point or three-point inverter, a feedback circuitry is provided, which is disposed in parallel with a feedback capacitor (CR), and essentially include a semiconductor valve (SR) and a transformer (TR). As a result of switching the semiconductor valve (SR) once, the energy of the protective-circuit reactances, which have been stored in the feedback capacitor, is fed back into the link-circuit voltage source by the transformer. The arrangement according to the invention is distinguished by a high efficiency, accompanied at the same time by high turn-on/turn-off frequency of the semiconductor switch.

Abstract: Supply circuit adapted to supply a magnetron (1) and comprising a high loss inductive voltage increasing transformer (8) whose primary winding (13) is mounted in series with a commutation element (14) adapted to chop the voltage and whose secondary winding (19) is connected to the load (1). The circuit comprises also a self inductor (17) mounted in series with the primary winding (13) of the transformer (8), as well as a condenser (18) connected in parallel to the primary winding. The commutation element is a unidirectional current gate (14), and the secondary winding (19) of the transformer (8) is directly connected to the load (1). The circuit is useful, for example, in microwave ovens.

Abstract: An assembly is made enabling an inverter of a high-voltage generator to pass from a full-bridge use to a half-bridge use, in replacing a connection circuit of a mid-point of a first rectifier of this generator at a mid-point of the inverter by a circuit that is frequency controlled at the rate at which the inverter itself is controlled. By this approach, the two assemblies are made compatible and it becomes possible to pass from one assembly to the other as a function either of a high power to be supplied or of a ripple, which cannot be tolerated, of a residual voltage rectified by a second rectifier.

Abstract: A power converter apparatus for an electric train, including at least a first modular power converter unit having a main circuit formed of switch for interrupting power from a D.C. power source, a first D.C.-A.C. power converter connected to the switch, an isolation transformer connected between the D.C.-A.C. power converter and a rectifier and a second D.C.-A.C. power converter connected to the rectifier. The switch and the first D.C.-A.C. power converter are controlled by a control signal derived from the difference between the output voltage of the first D.C.-A.C. power converter and the sum of a delayed soft starting control signal and a settable reference signal. The second D.C.-A.C. power converter is pulse width modulated. Preferably a second modular power converter unit having the same construction as the first unit is provided and has inputs connected in series or in parallel with inputs of the first unit.

Abstract: A power supply including a resonant converter is provided with current shunt. The current shunt automatically shunts a portion of current flowing in the resonant converter at light loading of the power supply such that output current flowing in an output circuit connected to the power supply would be reduced toward zero as the operating frequency of the converter moves to a predetermined frequency.

Abstract: A magnetron (M) serving as the microwave source in a microwave oven is driven by a Switch Mode Power Supply (SMPS). The resonance circuit of the Power Supply contains a transformer (Tr), the secondary side of which is connected to the magnetron via a voltage multiplier consisting of a rectifier and voltage doubler circuit (C3, C4, D3, D4). In order to obtain a feedback signal which is proportional to the power fed to the magnetron thereby to regulate this power, a current transformer (ST) is connected in series with one of the diodes (D3) in the rectifier and voltage doubler circuit. The output signal of the current transformer is compared in a control circuit (K) with a reference signal and the result of the comparison is used to control the switch frequency and thereby the magnetron power.

Abstract: A direct-current high voltage obtained by rippling, stepping-up and rectification of a direct-current low voltage is regulated in such a manner as to ensure that the maximum value of direct-current high voltage attains a predetermined peak value at each ripple pulse of the inverter. To this end, a following pulse of the inverter is produced as soon as the high voltage of the direct-current high-voltage signal has become lower than the predetermined peak value reduced by the measurement of a variation in said direct-current high voltage during a preceding pulse.

Abstract: A power supply circuit for a high-frequency source (M) in a microwave oven includes a switched-mode-power-supply unit having a resonant circuit which contains a coil (L2) and a controllable switch (D1). The switching of the controllable switch is controlled by a control circuit (K) via a driving stage (S). The power supply circuit is cooled by a fan (F). The required DC voltages for supplying the driving stage, control circuit and fan are obtained by means of an auxiliary winding (W1, W2) on the coil (L2) and a rectifier (D3, D4). This results in a saving in both space and costs. At the same time, automatic supervision of the different functional units of the power supply circuit is obtained.

Abstract: A series resonant power supply is switched at a constant frequency above the audio range, in which a magnetic amplifier is used to control the magnitude of the output voltage. It can be run silently, while providing high power at relatively low cost. The power supply includes a full or half bridge rectifying circuit with first and second common terminals. A magnetic amplifier is coupled from the first common terminal to a second common terminal. The magnetic amplifier includes a first primary coil for conducting current from the first common terminal to the second terminal. A secondary coil for generating an output current, and a control coil receiving a control current are coupled with the first primary coil. A second primary coil is connected to conduct current from the second common terminal to the first common terminal. A second secondary coil and a second control coil are coupled with the second primary coil.

Abstract: Low-loss external wiring, for the switching-off relief of the semiconductor switching elements in a stage of a three-level inverter provides a switching-off relief capacitor which is connected to the stage output. Wiring capacitors are coupled to each of the upper and lower ends of the stage. The inverter also includes a diode network. Additional d-c consumers which are preferably either ohmic resistors or energy recovery devices take up energy which is interim-stored in the wiring capacitors.

Abstract: A series inverter, high voltage capacitor charging circuit includes current sensors for sensing the current through each SCR in the circuit. The sensed current is used to vary the gating frequency of the SCRs and to preclude firing of an SCR until the other is in a stable off condition. The gating of each SCR is delayed by an amuont of time determined by a control capacitor charging circuit. That charging circuit is inhibited as long as one of the SCRs is conducting and once the load voltage has reached a predetermined level. The time constant of that charging circuit can be changed as the desired level is approached of if insufficient reverse bias is applied to an SCR for quick turn-off of the SCR. Resolution of the system can be increased by a shunt regulator which shorts the output transformer. The circuit can be disabled if the high voltage capacitor does not reach its set level within a given time.

Abstract: A power supply circuit of voltage resonance type for supplying a high DC voltage to an X-ray tube includes a transformer, a capacitor for forming a resonance circuit in cooperation with a primary winding of the transformer, and a rectifier circuit coupled with a secondary winding of the transformer for supplying a high DC voltage to the x-ray tube. At the beginning of the operation of the power supply circuit, a great change of resonance conditions is offset to quicken the rise of the X-ray tube voltage. To this end, a power supply drive circuit to enable (turn on) the switches is arranged to prevent the switches from being enabled before one cycle of the resonance current in the resonance circuit is completed.

Abstract: The invention relates to a method and to an arrangement for controlling the respective conduction times of two directionally opposed electrical devices (9,10) which are mutually connected in parallel and permit current to pass therethrough solely in one direction, and which also permit current (I.sub.2) to pass through the primary winding (2) of a transformer during a respective half-period of an A.C. voltage (U.sub.1) applied to the primary winding, this control being effected so that the magnetizing current through the transformer can be advantageously minimized and/or held beneath a given limit value when an asymmetric load (4,5) is applied to the secondary side (3) of the transformer. A magnetizing current in the primary winding corresponding to the load (5) of the secondary winding (3) is controled through the agency of different conduction times of the two directionally opposed devices (9,10).

Abstract: In order to scrub a waste gas, for example, of foreign matter by means of an electrostatic filter, a power supply is provided which contains a converter whose output feeds the primary winding of a high-voltage transformer. The secondary winding is connected to the electrostatic filter via a high-voltage rectifier. Disposed in the intermediate circuit of the converter is a control element for the intermediate circuit current. This shields the supply network against the effects of the power converter commutations and of short-circuits in the filter to a great extent. A limiter for the filter voltage and a temporary separation of the transformer from the inverter in case of filter short-circuits may be provided to reduce the stress on the components which can be made small if a high-frequency working cycle for the setter and the inverter is used.

Abstract: An energy converter of the type utilizing a series-resonant bridge circuit (1) containing at least two thyristors (6A, 7A, 6B, 7B) with diodes (8A, 9A, 8B, 9B) antiparallel connected thereto, a high-frequency output transformer (12), and an energy buffer (2). A control circuit (3) is incorporated for generating trigger pulses for the appropriate thyristors in response to the energy of the buffer (2). The energy converter further comprises a switching circuit (24) connected in at least one of the supply lines of the supply source to the series-resonant circuit for ensuring that the diode, antiparallel connected to the last-conducting thyristor, starts to draw current immediately after this thyristor is blocked. The control circuit (3) furthermore generates signals indicative of the presence of current flowing through the diodes, which signals control the supply of the trigger pulses to the thyristors.

Abstract: A pulse arc welding power supply incorporating one or more series resonant converters (SRC) for converting D.C. power to A.C. power which is then rectified to supply welding current. Each series resonant converter includes a series resonant tank circuit consisting of a capacitor, an inductor and the primary winding of a transformer whose secondary winding supplies current to the welding arc. The undesirable secondary output capacitor of the prior art is eliminated, as all the capacitance in the series resonant circuit is located on the primary side of the transformer. Current sensors sense the ringing current in the resonant circuit and also the load current and produce respective feedback signals which are used to control the switching frequency of an SCR bridge in the tank circuit, thereby maintaining the welding current at a desired value.

Abstract: A versatile current source inverter power supply for an ozonator in which a gating control circuit controls the gating of a thyristor bridge inverter power supply in a manner in which the output current to the ozonator is controlled and regulated. The current source inverter power supply circuit includes a DC/AC thyristor bridge inverter circuit coupled at its input terminals to a direct current power source and at its output terminals to an electrical network which includes the capacitative ozonator load. The thyristor bridge inverter includes a first pair of thyristors and diodes coupled to conduct current in a first direction through the electrical network, and a second pair of thyristors and diodes coupled to conduct current in a second, opposite direction through the electrical network. The electrical network includes a step up high voltage transformer, with its primary winding coupled to the thyristor bridge inverter and its secondary winding coupled to the ozonator load.

Abstract: A high voltage DC/DC converter including a voltage resonance switching circuit formed by a coreless transformer, a GTO thyristor switching element connected between the primary winding of the transformer and a D.C. source, and a voltage resonance capacitor connected in parallel to the switching element. A rectifier circuit is connected to the secondary winding of the transformer to rectify an output current from the transformer circuit. The resonance frequency of the parallel resonance circuit made of the resonance capacitor and the coreless transformer is selected to be the frequency of that component of the current supplied to the circuit through the switching element, which has a greater amplitude than any other component of the current (including the fundamental frequency and other harmonic).

Abstract: A bridge inverter arrangement for use with high-voltage generators for X-ray apparatus includes a single phase transformer having primary and secondary windings, a capacitor series-connected via a current-limiting resistor to the primary winding so as to constitute a series resonant circuit, a bridge inverter having series-connected thyristors for inverting DC low voltage into pulsating low voltage, and a switching controller for controlling turn-on times of the thyristors. A switching circuit is connected in parallel to the resistor. The switching circuit is controlled under the switching controller in response to switching signals for the thyristors so as to vary the value of the pulsating low voltage, thereby changing the value of high AC voltage induced at the secondary winding and reducing the ripple components contained therein.

Abstract: A high voltage power supply system includes a DC-to-DC converter for producing a DC low voltage, a DC-to-AC inverter connected to a step-up transformer for producing an AC high voltage by transforming an AC low voltage obtained from the DC low voltage, and an inverter controller for controlling an operation time period of the DC-to-AC inverter longer than that of the DC-to-DC converter. Since a residual charge stored in a capacitor of the DC-to-DC converter is rapidly discharged by lengthening the operation time period of the DC-to-AC inverter, an unwanted AC high voltage is induced at a secondary winding of the step-up transformer.

Abstract: According to the invention, the system comprises a resonance type inverter, a diode rectifier bridge and single regulation loop controlling controlled switching means, forming a chopper, interconnected between the rectifier bridge and the inverter. The system is applied to X-ray equipment.

Abstract: A series resonant converter is interposed between an unregulated voltage source and an output circuit. The converter employs a pair of power switches each, when on, completing a series resonant circuit from the source to a resonant tank circuit including the primary winding of a transformer coupled to the output circuit. The power switches are alternately turned on and off so that sinusoidal current pulses alternately flow in opposite directions in the primary winding at a frequency dependent on input and output conditions. The current flowing in the resonant circuit is monitored and the power switches are additionally controlled to prevent turn on of one switch and turn off of the other when current is still flowing in the resonant circuit.

Abstract: A power supply 10 providing a DC output voltage comprises a voltage input circuit 11, a charge buildup and transfer circuit 14, a switch including SCR3 for selectively interconnecting the input circuit 11 and the charge buildup and transfer circuit 14, a trigger circuit including a unijunction transistor gating circuit 16 for triggering the SCR3, and a sensing circuit 22 including a current reference 26 for sensing the current output to the load 38 and comparing the output to current reference 26 while providing a comparison signal to the trigger circuit 16 so as to modify the triggering of SCR3 and thus the interconnection of the voltage input circuit 11 and the current buildup and transfer circuit 14.

Abstract: An apparatus for supplying high voltage pulsed direct current to an X-ray tube includes a transformer, a high frequency inverter circuit and a nonlinear feedback loop. The invention uses the high frequency inverter connected in series with a DC power supply source and the primary winding of the transformer in order to generate high voltage, high frequency AC in the secondary winding. A rectifier connected to the secondary winding supplies high voltage pulsed DC to the X-ray tube. A detector, such as a voltage divider, detects the voltage supplied to the X-ray tube and supplies a representation of it to a nonlinear feedback circuit connected between the detector and the high frequency inverter. The inverter circuit includes at least one switch generated by electrical pulses.

Abstract: A power supply is provided for supplying regulated power to an output from an unregulated DC voltage source. The supply includes low and high power series resonant converters, each including a pair of power switches which are alternately turned on and off for completing a series resonant circuit with the source and with a primary winding of a transformer coupled to the output. A switch control responds to loading of the output and drives the switches on and off at an operating frequency that varies with the loading. A converter control monitors the operating frequency and controls operation of the converters such that one or both converters operate in dependence upon loading to avoid operation within a particular frequency range.

Abstract: A power supply for providing a selectable predetermined regulated output voltage. A switching regulator circuit provides the conversion of an input voltage to a DC output voltage and a control circuit, which senses the output voltage, controls the conversion of the switching regulator circuit. In the present invention, an amplifier, having selectable gain values, is interposed in the feedback loop, i.e., between the output terminal of the power supply and the control circuit. Thus a predetermined portion of the output voltage is fed back to the control circuit, thereby selectively determining the output voltage without necessitating changes to the switching regulator circuit or the control circuit.

Abstract: A resonant type constant voltage supply apparatus has a LC series resonance circuit. Energy stored in both a resonance capacitor and a resonance inductor is directly transferred to the output or input terminal of the apparatus. A control transformer is provided in parallel with the resonance capacitor for deriving the energy stored in the resonance capacitor. The amount of the energy stored in the resonance capacitor can be controlled by changing the switching frequency of the apparatus or the inductance of the control transformer, so as to thereby control the amount of energy transferred to the output or input terminal of the apparatus and thereby stabilize the output voltage of the apparatus.

Abstract: A chopping type electrical converter having a primary circuit utilizing controlled rectifiers for chopping the input voltage, a secondary circuit for providing a DC output voltage, and a control unit which continuously monitors current flow in the secondary circuit and delays trigger pulses to the controlled rectifiers in the primary circuit whenever it is unsafe or undesirable to trigger them. In a preferred embodiment, the controlled rectifiers are mounted in series-connected pairs with a step-down transformer for each controlled rectifier. The number of pairs and the interwoven triggering order of the controlled rectifiers enables high voltage and high frequency operation with minimal stress on the converter components. The control unit prevents each member of each pair of controlled rectifiers from being triggered whenever the other member of the pair is still conducting, or whenever current is flowing in the secondary winding of the transformer associated with the controlled rectifier.

Abstract: An energy converter comprising a series-resonant bridge circuit (1) containing at least two thyristors (6, 7), first and second respective diodes (8, 9) connected antiparallel thereto, a high-frequency output transformer (23), and an energy buffer (2). A control circuit (20) is incorporated for generating trigger pulses for the appropriate thyristors in response to the energy of the buffer (2). The energy converter comprises means for ensuring that the diode, antiparallel connected to the last-conducting thyristor, starts to draw current immediately after this thyristor is blocked. The control circuit also generates signals indicative of the presence of current flowing through the diodes (8, 9), which signals control the supply of the trigger pulses to the thyristors (6, 7).

Abstract: An inverter system having a plurality of resonating current supplying stages connected in parallel, all resonant at the same frequency. The rate at which the stages operate is controlled by a feedback circuit responsive to the load output. The rate is maintained above the audible range for all but small total current values. Should the rate tend to vary outside a predetermined range, a different combination of stages is switched in. The stages supply currents which are binary weighted.

Abstract: A voltage converter apparatus is provided to energize a first load and a second load from a power supply connected through an inverter and a coupling transformer, with the transformer having a first secondary winding energizing the first load with first voltage pulses having a variable width determined by the operational frequency of the inverter and having a second secondary winding energizing the second load with second voltage pulses having a variable width determined by a phase controlled switching apparatus responsive to one of the voltage and the current of the second voltage pulses.

Abstract: A dc-dc converter employs a series resonant circuit which is driven by square waves of current. By adjusting the frequency of the square waves of current above the resonant point or by holding the frequency constant and varying the current supplied to the converter, the voltage on the resonant components can be stepped up and controlled. Switching losses in the inverter gate turn-off devices are low since the inverter feeds a lagging load which allows the use of lossless snubbers.

Abstract: A DC-DC converter that has an AC link includes an input current type inverter and an output voltage type inverter coupled together by a transformer. The negative terminal of the current type inverter is connected in series with the positive terminal of the voltage type inverter. Controlled rectifiers are used in the current type and voltage type inverters and the angle, relative to a fixed point in the AC cycle, at which the controlled rectifiers are turned on and off is varied to obtain desired converter action. A substantially smaller transformer, thus, is required.

Abstract: A dc-dc converter employs a parallel resonant circuit which is driven by square waves of current. By adjusting the frequency below the resonant point, the voltage on the resonant components can be stepped up. Switching losses in the inverter devices are low since the inverter feeds a lagging load allowing lossless snubber operation which allows the use of lossless snubbers.

Abstract: A high power generator for an ion discharge device used for the thermal treatment of metals in a rarified gaseous atmosphere. A variable width pulse generator is used to vary the input power to an inductance means. The frequency of the input pulses is held constant, while the pulse width is varied. An arc protection circuit is provided to sense and prevent an incipient arc across the secondary of the transformer. The arc protection circuit includes a voltage detector and a current detector with logic means to sense an under voltage-over current condition that presages the beginning of an arc. A second embodiment is disclosed which uses two circuits in parallel to drive the ion generator. One circuit is charged while the other is discharged. A third embodiment is disclosed which was a thyristor network for selectively loading the primary circuits of a pair of inductance circuits in response to an inductance-capacitance time constant.