Abstract: A flash charging circuit has first and second transistors (TR1, TR2) which are connected to opposite terminals of a primary coil of a transformer, a battery is connected to a center tap provided in a middle portion of the primary coil, and first and second drive pulse signals (S1, S2) are applied to the first and second transistors to drive them alternately with each other, to induce an alternating secondary current in a secondary coil of the transformer. Each of the first and second drive pulse signals have a shorter pulse duration (Pd) than a pulse separation (Ps). The phases of the first and second drive pulse signals are determined such that both the first and second drive pulse signals take a low level for a time (Ta) before and after each drive pulse of the first and second drive pulse signals, so that both the first and second transistors are OFF immediately before either of them is turned ON.

Abstract: This push-pull switching power supply outperforms its counterparts. Each switch has twice the voltage ratings. However, only two main switches have current ratings as all four switches of the full-bridge power supply. That is only one half the current ratings of both switches of the half-bridge power supply. The input voltage is applied to a center tap of transformer's primary winding. The main switches are coupled thereacross for alternately applying the primary current to ground. Two diodes apply the leakage current of the transformer to a single capacitor. One or two auxiliary switches apply the primary current to the capacitor, whereby the leakage energy stored therein is immediately returned to the transformer. The auxiliary switches operate only a mere fraction of the time and thus their peak rather than continuous current ratings matter. The efficiency is significantly increased as a passive snubber network is eliminated and a reverse energy flow is prevented.

Abstract: A converter has an assembly with a transformer primary and secondary windings and two pairs of primary and secondary choke windings wound around a core. Switching circuits are coupled between the transformer primary winding and the two primary choke windings. Each switching circuit has a capacitor, diode and a MOSFET. The MOSFETs are switched on and off in a cyclical manner to provide a continuous output current from a continuous input current by operating in a push-pull manner.

Abstract: A circuit arrangement for multiple use of a transformer core, comprising a winding with center tap on the primary side and two separate windings on the secondary side, has a controlled switch in each feed line for the two primary windings which is preferably clocked with high frequency. A rectifier is connected to the first secondary winding in particular for forming a switching power supply, which is thus supplied with energy. An FET transistor is coupled to the second secondary winding, in particular for forming a driving pulse transmission, preferably via two Z-diodes with anti-serial connection, which transistor is thus supplied with driving pulses. The magnetic circuit for the transformer is actuated via switches which change polarities on the primary side of the transformer. The switch-on pulse duty factor for the switches is selected to be higher than 50%.

Abstract: Disclosed is a ballast circuit for a gas discharge lamp comprising a resonant load circuit incorporating the gas discharge lamp, a resonant inductance, and a resonant capacitance. A d.c.-to-a.c. converter circuit induces an a.c. current in the load circuit, and comprises first and second converter switches serially connected in the foregoing order between a bus conductor at a d.c. voltage and a reference conductor. The switches are connected together at a common node through which the a.c. load current flows. The switches each have a control node and a reference node, the voltage between such nodes determining the conduction state of the associated switch. The respective control nodes of the switches are interconnected, and the respective reference nodes of the switches are connected together at the common node.

Abstract: In a resonant DC-DC converter for converting a d.c. input voltage into a d.c. output voltage, a main switching element (3) switches the d.c. input voltage under control of switching pulses to supply an a.c. voltage to a primary side of a transformer (4). A resonant circuit (5) is provided at a secondary side of the transformer. A clamp circuit is connected to the main switching element and comprises a first capacitor (2-1) and an auxiliary switching element (2-2) serially connected to the first capacitor. The main and the auxiliary switching elements are alternately put into an on state under control of the switching pulses.

Abstract: A standby power system is provided having power conversion, output voltage control, and line-fault detection systems that make possible a significant reduction in the cost of the system. The standby power system provides backup power to a load, such as a computer system, when main AC line power fails. A system DC battery voltage is converted to an AC output voltage signal at line voltage levels by a power conversion system including a high frequency push-pull inverter, a light-weight low-cost high frequency transformer, a rectifier, and a line frequency inverter. The high frequency inverter is controlled to provide high frequency battery voltage pulse bursts separated by low frequency zero voltage dead times which are boosted by the transformer to line voltage levels and rectified by the rectifier. The line frequency inverter is controlled to provide the rectified line voltage level pulse bursts to the standby power system output in the form of a stepped square wave output signal at line frequencies.

Abstract: In a voltage converter for converting an AC input voltage into a DC high voltage and further DC power supply voltages, in which the AC voltage applied to the converter is applied to a rectifier arrangement (1, 2, 3, 4) whose output signal is coupled to two consecutively switched electronic switches (6, 7), and in which this DC voltage is converted into the DC high voltage and into the DC power supply voltages, the circuit arrangement has a simple structure in that a series arrangement of a capacitance (8), an inductance (9) and a primary winding (10) of a transformer (11) is arranged in parallel with one of the electronic switches (6, 7), in that a secondary winding (12) of the transformer (11) precedes a capacitance (15) at the output end, in that a control circuit (20) is provided which controls the switching frequency of the electronic switches (6, 7) in such a way that a DC voltage of the desired value decreases across the capacitance (15) at the output end, and in that the transformer (11) is provided wi

Abstract: Herein disclosed are a method and an apparatus for supplying an electrical energy to a pair of discharge electrodes spaced apart from each other to cause an electric discharge in a gap between the discharge electrodes. There are firstly provided an alternating voltage generator for generating, as the electrical energy, an alternating voltage having a frequency, and a capacitor connected to the discharge electrodes in series. The alternating voltage generator has a series resonant frequency. The alternating voltage of the alternating voltage generator is applied to the discharge electrodes through the capacitor. The frequency of the alternating voltage is set approximately to the series resonant frequency of the alternating voltage generator to cause a dielectric breakdown in and allow an electric discharge current to flow through the gap between the discharge electrodes.

Abstract: A converter has an assembly with a transformer having primary and secondary windings and two pairs of primary and secondary choke windings wound around a core. Switching circuits are coupled between the transformer primary winding and the two primary choke windings. Each switching circuit comprises a capacitor, diode and a MOSFET. The MOSFETs are switched on and off in a cyclical manner to provide a continuous output current from a continuous input current by operating in a push-pull manner.

Abstract: A power supply of the high frequency series resonant mode family for supplying power to audio amplifiers includes half and full bridge variations and supplies all of the required rail voltages while maintaining fixed frequency resonant operation throughout all combinations of loading of the amplifier outputs without the need for a large explicit resonant inductance. The elimination of switching loss enables the use of power supply switching devices optimized for low conduction loss, further improving performance under high current conditions. The power supply frequency is fixed by an oscillator of sufficient precision to ensure that the beat frequency that will result from heterodyning of the residual switching frequency noise between two identical but separate power supplies will be in the infrasonic range. Protection circuitry is provided to limit peak switch currents during the start up interval.

Abstract: An uninterruptable power supply module includes a DC power supply having an output for outputting a first DC voltage signal, a battery backup module in parallel connection to the output of the DC power supply and having an identical voltage level to that of the first DC voltage signal, boost converter means having an input coupled to the first DC voltage signal from the battery backup module for converting said first DC voltage signal to a second DC voltage signal, DC/AC conversion means having an input coupled to the second DC voltage signal from the boost converter means and an output for generating a first AC voltage signal in response to a variable duty cycle oscillation signal, pulse width modulator means powered by said battery backup module and having an output coupled to said DC/AC conversion means for generating said variable duty cycle oscillation signal, and shaping means having an input coupled to the first AC voltage signal from the DC/AC conversion means and an output for supplying a second AC v

Abstract: A DC-DC converter includes a transformer with two oppositely-wound primary windings, one on each side of a center tap, and at least one secondary winding connected to a load having a given capacitance. A reference voltage source is connected to the center tap of the transformer via an inductor so that the transformer is driven by a current source. Two switching devices are each connected in the return path of the reference voltage and in series with a respective primary winding. A control unit alternately and periodically connects the return path for the reference voltage to one or other of the primary windings. The control unit includes an oscillator generating squarewave signals has two complementary outputs connected directly to a control terminal of a respective switching device. The frequency of the oscillator is substantially equal to the resonant frequency of a circuit comprising the secondary inductance of the transformer and the capacitance of the load.

Abstract: An uninterrupted power supply system including a square wave oscillator, a square wave drive, a negative wave drive, a first bridge drive, a second bridge drive, a bridge circuit, a R/C low pass filter, an overload protection circuit, a high-voltage generator, and a full-wave rectifier, wherein the bridge circuit consists of pairs of oxide metal field effect transistors (insulated-gate semiconductors) respectively connected by bridging for the conversion of DC power supply into AC power supply; the high-voltage generator and the bridge circuit are mounted on an expansion card so that the output power of the system can be expanded by installing additional expansion cards.

Abstract: A DC--DC boost converter for directly driving a capacitive load employs four switches for cyclically commuting the connection configuration of an energy storing inductor. First and second switches are driven at a relatively high frequency and provide an impulsive charge path of the inductor by connecting one or the other end to a power supply rail. Third and fourth switches are driven in phase opposition to each other at a relatively low frequency and provide a discharge path from one and the other end of the inductor, respectively, toward an output node of the circuit to which the capacitive load is connected.

Abstract: In an AC to DC power converter (off line switcher) and a method of converting AC power to DC power in high voltage systems the flyback converter's low side semiconductor switch has a lower breakdown voltage than its high side semiconductor switch. The lower breakdown voltage is achievable by means of a shunt regulator that controls a clamp voltage across the low side switch. The efficiency of the converter's post regulator is improved by processing only a fraction of the system's total power output.

Abstract: A bipolar output transformer for use in a automobile audio amplifier. The transformer includes series connected primary and secondary windings and a diode bridge which together step up an input voltage providing an increased bipolar output voltage for efficient interface to the direct coupled power amplifier components.

Abstract: A single stage high frequency push-pull converter with input power factor correction. The boost converter for input power factor correction and the high-frequency push-pull DC/AC inverter are combined into a single stage converter thereby reducing the number of circuit components while at the same time reducing the voltage stress on the high frequency switching transistors of the converter.

Abstract: A low loss clamp circuit is provided for a dc to dc converter. The converter has a transformer with a secondary winding and a secondary circuit and a center tap primary winding. A dc voltage input is supplied to the primary winding center tap and to a circuit ground. A rectifier such as a bridge rectifier connects to two ends of the secondary winding and to the circuit ground to supply a dc output voltage. A pair of semiconductor switches such as FET switches are provided. Each end of the primary winding is connected through a respective switch to the common ground. The various circuits have energy storage means including the input capacitor 31 and input choke 32 in circuit with the primary winding. It will also be noted that the output capacitor 29 is a part of the energy storage means. This energy storage means is connected to return energy to the secondary circuit, not the primary circuit.

Abstract: The present invention provides a resonant power converter for changing the magnitude of a DC voltage. The converter includes a common magnetic core with three legs (an "EE" core). The core has primary and secondary windings wound onto a first outside leg, and a tank winding and control windings wound onto a second outside leg. Control switch means are provided for effecting alternate pulses of current flow through the primary winding to effectuate alternate flux flow, the control switch means and the primary winding having a predetermined parasitic capacitance with a predetermined delay time between the termination of a given pulse and initiation of the succeeding pulse. The secondary windings are oriented to conduct alternately in phase with the alternate flux flow, there being inherent in the first leg of the transformer a magnetizing inductance, such that the magnetizing current will be great enough to charge said parasitic capacitance in a controlled fashion.

Abstract: A power supply circuit of a switching inverter type includes a switching circuit including two switching elements capable of being alternately on-off controlled for converting an input from a dc power source into ac by switching of the switching elements and outputting it, a dc output circuit for full-wave rectifying and smoothing a supplied ac input to provide a dc output, a series resonance circuit provided in series to current flowing from the output terminal of the switching circuit, a parallel resonance circuit provided in parallel to voltage produced at the output terminal of the switching circuit, and a switching control circuit for intermittently turning on the switching elements of the switching circuit.

Abstract: A transformer has a secondary winding with an intermediate tap. Two switching elements are connected in series between terminals of the primary winding. A dc power source is connected between a connecting point of the switching elements and the intermediate tap of the primary winding. By turning on and off the switching elements alternately, parallel resonance is produced by primary self inductance and a capacitor provided on the primary side of the transformer. Series resonance is produced by leakage inductance between the primary and secondary sides and a capacitor provided on the secondary side. Turning on of the switching elements at a zero-voltage state and turning off of the switching elements at a zero-current state are realized. Since this transformer is a push-pull type one, currents flowing through the switching elements are reduced to half of a half bridge type transformer.

Abstract: This resonant power supply produces a varying magnetic field from a resonant inductor. Two active switches drive, but remain outside, a resonant circuit, also including resonant capacitor. A phase-splitting transformer provides, via a decoupling inductor, one connection for a power supply; the return is through the active switches, which are either off or are from time to time driven alternately by the controller so as to maintain the resonant current in the resonant circuit. Applications include induction heating and induction hobs for cooking, and also a power source for inductively powered vehicles (or other inductively powered devices) adjacent to an inductive pathway.

Abstract: A turn-off relief network for a direct voltage converter includes a transformer having a primary winding. At least one clocked power transistor is connected in series with the primary winding. A first series circuit connected parallel to the primary winding includes a diode and a capacitor. A second series circuit connected parallel to the capacitor includes a reversing inductor, a reversing diode for a capacitor voltage and another transistor.

Abstract: A switching regulator having a series resonance push-pull converter (GW) and two clocked boost regulators (AR1, AR2) connected in series with the converter, wherein: the converter comprises a transformer (Tr) having two primary windings (w1, w2) which are galvanically isolated from one another, and two push-pull switches (S1, S2) each connected in series with a respective one of the primary windings; each of the boost regulators comprises a series inductance (L1, L2) and an output capacitor (C1, C2); and the boost regulators are connected to the converter to form two push-pull branches, each of the push-pull branches being composed of the series inductance of one of the boost regulators connected in series with a respective one of the primary windings and a respective one of the push-pull switches, and the output capacitor of each of the boost regulators constituting a resonance capacitor of the converter.

Abstract: A Circuit for reversing the direction of current flow in a rectifying device of a power converter during a time interval just prior to when the rectifying device is to be rendered non-conductive is described. The current reversal substantially reduces or eliminates reverse-recovery currents in the rectifying device, which may cause short circuits and needlessly dissipates power. The circuit comprises an energy source, a magnetic storage device, and a switch for coupling the magnetic storage device to the energy source. The magnetic storage device may comprise an inductor or a transformer. The energy source may include a voltage source, the converter's input voltage, the output voltage, or a winding magnetically coupled to another magnetic storage device of the converter. The reversal circuit includes a circuit for coupling the reversing current to the rectifying device such that it partially or completely reverses the flow of current in the rectifying device.

Abstract: An electrical power inverter having an output voltage waveform that closely corresponds to a reference waveform under a wide range of load conditions is disclosed. The present invention allows for excess energy present at the output port of the electrical power inverter to be coupled back to the input port to maintain the correspondence of the output voltage waveform with the reference waveform when the inverter is providing power to inductive or light resistive loads.

Abstract: The present invention relates to a hybrid power supply for converting an alternating input signal fed to its input into a direct output signal produced at its output. The hybrid power supply comprises a rectifier for converting the alternating input signal into a mono-alternation signal; a capacitor for smoothing the mono-alternation signal into a direct signal; a switching regulator stage coupled to the capacitor for generating a pre-regulated direct signal having a constant amplitude; a 1/X frequency modulating circuit for generating two switching pulsed signals of constant pulse width at a variable frequency according to a 1/X function in relation to the direct signal originating from the capacitor; and a linear regulator stage coupled to the switching regulator stage for regulating the pre-regulated direct signal, and for generating the direct output signal.

Abstract: A power source having a first rectifier, a transformer having a primary coil and a secondary coil, switching elements having one end thereof connected to one of the terminals of the primary coil, a capacitor connected between other ends of the switching elements, diodes respectively connected between the terminals of the primary coil and the other ends of the switching elements, a choke coil for supplying the input DC voltage from the first rectifier directly to one of the terminals of the primary coil, and a second rectifier for supplying an output DC voltage to a load by rectifying the output AC voltage from the secondary coil.

Abstract: A highly efficient, tuned, switching power amplifier has components in a circuit configuration which minimizes switching losses and stored energy within the circuit. The circuit includes a pair of switches operating at the carrier frequency at substantially 50% duty. The switches are coupled through a transformer to a load, with the circuit being tuned, taking the particular load into account, so as to minimize the power loss in the switches by ensuring that immediately prior to, and during each, transition of each switch from its non-conducting (off) state to its conducting (on) state, both the voltage across the switch and the first derivative with respect to time of the voltage across the switch are substantially zero.

Abstract: A voltage converter is provided comprising a primary circuit which, with an input voltage, is connected through at least one primary winding to at least one respective secondary winding of at least one secondary circuit. The primary circuit and the at least one secondary circuit are tuned individually so that each comprises an oscillatory circuit with coinciding resonance frequencies.

Abstract: A pulse-width modulated, bi-directional DC-to-DC voltage converter having a regulated output, and capable of converting between a high-potential direct current voltage and a low-potential direct current voltage. The converter's magnetic components, as well as several of its semiconductor rectifiers, perform dual functions (one in the step-up mode, and another in the step-down mode), which serves to minimize the total component count, and allows the converter to be both compact and lightweight. Additionally, as the converter maintains a continuous input current during voltage step-up conversion, the generation of signals which might cause electromagnetic interference is reduced.

Abstract: The converter comprises a transformer having two primary windings; a voltage source having one of its terminals connected to the center tap; and two switches connected in series between the other terminal of the voltage source and a respective one of the primary windings, the switches having stray capacitances that impose a transition time between one of the switches switching OFF and the other switch switching ON. The transformer comprises a magnetic circuit having a gap, and each primary winding has a number of turns that is determined essentially as a function of the level of losses acceptable within the magnetic circuit, the size of the gap then being adjusted, taking account of the number of turns and the operating frequency, in such a manner as to reduce the magnetizing inductance of the transformer to a value such that said transition time is less than a given threshold corresponding to tolerances of the form factor.

Abstract: An unregulated D.C. input voltage (V.sub.IN) is processed by a high power chopper (34,36) to produce a first chopped signal having the same voltage as the input (V.sub.IN), and by a low power chopper (56,58) to produce a second chopped signal in synchronism with and having a lower voltage than the first chopped signal. The first and second chopped signals are algebraically combined by transformers (52,54) to produce an A.C. output signal which may be converted to D.C. (V.sub.OUT). The second chopped signal may be controlled to have the same polarity relative to the first chopped signal in which case the voltages add to increase the output voltage (V.sub.OUT), or to have the opposite polarity relative to the first chopped signal in which case the voltages subtract to decrease the output voltage (V.sub.OUT). The periods of addition and subtraction are alternated within the period of the first chopped signal.

Abstract: An integrated magnetic power converter for supplying power to a load includes a continuous magnetic structure having first and second legs and a magnetic path therebetween. Two transformers and two inductor devices are included on the core. The converter operates in four states determined by the state of two switches coupled to the transformer.

Abstract: The invention relates to a magnetic control process for transfering energy in a static converter comprising a voltage source (E) and an almost sinusoidal current generator IQS serially coupled with the primary winding of at least one saturable current transformer (TP). The secondary winding of the current transformer (TP) feeds a control circuit (C) which regulates as a function of one parameter, voltage or current, of this secondary winding the demagnetization of the whole magnetic circuit (TP) according to the desired energy transfer. The invention also relates to a static converter for implementing the method.

Abstract: Minimal energy storage is required in complementary converters, a family of zero-voltage switching circuits which achieve non-pulsating input and output currents by employing a ripple-cancelling technique instead of conventional filtering. The input voltage in these circuits is divided between a primary winding of a main transformer and a primary winding of a second transformer referred to as a complement transformer. The turns ratios of the two transformers are adjusted so that the secondary voltage of the complement transformer cancels the ripple in the rectified output of the main transformer. The symmetry of these circuits allows an AC voltage waveshape to be impressed upon the main transformer, independent of the load current passing through it. If desired, a sinusoidal voltage can be produced across the main transformer with only a small resonant current, which can be achieved with minimal energy storage.

Abstract: A circuit for converting on d.c. voltage to another d.c. voltage including a transformer having a center tap and first and second end leads. A d.c. source voltage is connected to the center tap of the transformer. The end leads are connected to ground through first and second MOSFETs and to the gate of the MOSFET through which the other end lead is connected to ground such that the circuit is nominally self-oscillating due to transformer saturation. Current spikes may be minimized with a control circuit, consisting of an oscillator, a flip-flop, and first and second transistors, connected to the gates of the first and second MOSFETs. The control circuit turns the MOSFETS off prior to their natural oscillation turn off caused by transformer saturation. The circuit is particularly suited to operation with a low voltage d.c. source and low voltage MOSFETS.

Abstract: New topologies for pulse width modulated resonant DC/DC converters are disclosed. The converters include a bridged chopper to convert the DC input to a high frequency AC which in turn is fed to a high frequency transformer whose secondary AC is rectified and filtered to produce a stable DC output. The bridged chopper has at least two semiconductor switches which alternately conduct. The duty cycles of the conduction of the switches are complementary with one another and adjustable to control the stable DC output. A resonant circuit is connected between the chopper and the high frequency transformer and contains a series capacitor, and a series or parallel inductor depending upon the preferred embodiment.

Abstract: A bootstrap circuit that operates in combination with switchmode DC to DC converter topologies that are based on forward (10), half-bridge/full-bridge (40) and flyback (60) configurations. Each configuration consists of an output circuit (18) and a bootstrap modified input circuit (12) that further consists of a bootstrap circuit (14) and a converter input circuit (16). The bootstrap function is achieved by charging a bootstrap inductor (L1) from current derived from the input voltage source and subsequently discharging the inductor through a bootstrap capacitor (C1) where an augmented voltage that is higher than the input voltage is developed. The converter then operates from the augmented voltage rather than from the input voltage. Thus, the invention is able to provide a constant output when operated over a wide-input voltage range while at the same time reducing the voltage stresses on the converter's primary switches and output rectifiers.

Abstract: Method and circuit arrangement for generating a sinusoidal line AC voltage from a DC voltage. For generating a sinusoidal line AC voltage from a DC voltage, the DC voltage is converted into a square-wave voltage having voltage pulses whose durations are controlled in accordance with the variation of the sinusoidal line AC voltage to be generated. The square-wave voltage is transmitted via a high-frequency transformer. Subsequently, the transmitted voltage pulses are respectively tapped and filtered for a given chronological duration. A secondary side of the high-frequency transformer is respectively shorted during pulse pauses caused by the sinusoidal control of voltage pulse durations for a simultaneous constant applied pulse frequency. In these phases, energy is transmitted back to the source of the DC voltage via the high-frequency transformer. As a result, the circuit arrangement can also be employed as a charging circuit.

Abstract: A circuit for reducing the commutation transient in a switch-driven (12) free-wheeling rectifier (20) applied to a load (10) via a continuously conducting energy conducting inductor (28), in which a further inductor (34) and diodes (32, 38) are interconnected with the switch-driven rectifier (20) to free-wheel recovered commutation energy from rectifier (20) when the switch is non-conducting. In other circuit variations temporary energy storage is aided by one or more capacitors (72) and additional diodes (52, 54, 80, 107, 122) during turn-on of rectifier (20), which energy recycled back into the circuit to minimize power dissipation and reduce circuit component heating.

Abstract: A pulse-width modulated, bi-directional DC-to-DC voltage converter having a regulated output, and capable of converting between a high-potential direct current voltage and a low-potential direct current voltage. The converter's magnetic components, as well as several of its semiconductor rectifiers, perform dual functions (one in the step-up mode, and another in the step-down mode), which serves to minimize the total component count, and allows the converter to be both compact and lightweight.

Abstract: A zero voltage switching DC/DC converter comprises a transformer with two opposed primary windings between which is a center tap and at least one secondary winding connected to a load by a rectifier and capacitor filter circuit. A first terminal of a constant voltage supply is connected to the center tap of the transformer. Two switching units are each connected in series between the second terminal of the voltage supply and a respective primary winding. The switches connect the second terminal of the voltage supply alternately and periodically to one or the other of the primary windings. A control device imposes between opening of one switch and subsequent closing of the other switch a switching time during which both switches are open.

Abstract: Current-fed push-pull converter. In a current-fed push-pull converter that is composed of a step-down regulator and of a push-pull controlled transformer, the transformer is connected following the step-down regulator. The converter also has push-pull switches, a transformer unit and at least one DC voltage top circuit for a respective output DC voltage. The transformer unit is formed by an auto transformer.

Abstract: A high frequency matrix transformer comprises a plurality of interdependent magnetic elements interwired as a transformer. The various component parts of the high frequency transformer are arranged and interwired to provide a transformer having very low leakage inductance and very good coupling from the primary to the secondary. The high frequency matrix transformer is particularly well adapted for transformers requiring high equivalent turns ratios, high frequency, high power, and high dielectric isolation. It can have a plurality of parallel secondaries, which can source current to parallel rectifier circuits with current sharing. It can also have a plurality of parallel primary circuits, which also will current share, to balance the load between source switching circuits, or to provide dual input voltage capability (i.e., 120/240 volts). The high frequency matrix transformer tends to be spread out, and can be very flat, making it easy to ventilate or heat sink.

Abstract: A novel resonant DC-to-DC converter has a source of direct current which is switched through a primary inductor, or the primary winding of a transformer in a primary circuit, to provide energy to an LC tank circuit. The sinusoidal, AC tank voltage is impressed upon an output winding that feeds an output smoothing inductor through a full wave rectifier. The resultant direct current output is made availabe to a load. A unidirectional switch operates in response to a switch control to perform the switching in the primary circuit at near zero current conditions. The switch control opens the unidirectional switch to end the current pulse. The length of the current pulse is proportional to the magnitude of the load.

Abstract: A DC to DC converter employs a push-pull oscillator which employs a transformer having a primary winding and a plurality of secondary windings. The transformer has a core which is of a square loop hysteresis type. The push-pull oscillator is supplied operating voltage by means of a voltage regulator circuit which operates to regulate the voltage applied to the push-pull oscillator according to both input voltage variations and output load variations. An output secondary winding of the transformer is coupled to a full wave rectifier. The full wave rectifier output is fed back to the regulator to control the voltage applied to the push-pull oscillator via the regulator. Due to circuit operation, the output voltage is extremely well regulated while having low ripple.

Abstract: An improvement is provided for a circuit having a first winding of N.sub.1 turns connected in series with a total inductance of L across a first voltage V.sub.1 and a second steering winding of N.sub.2 turns connected in series with a total inductance L.sub.2 across a second voltage V.sub.2 with the second winding magnetically coupled to the first winding and the first winding having an inductance L.sub.c produced by the N.sub.1 turns as seen across the first winding comprising L.sub.1 set substantially greater to zero and L.sub.2 set substantially equal to (L.sub.c) (N.sub.2 /N.sub.1).sup.2 ((V.sub.2 /V.sub.1) (N.sub.1 /N.sub.2)-1)). The setting of L.sub.1 and the setting of L.sub.2 providing an improvement to reduce ac ripple current.

Abstract: A flexible bulk container for the handling and storage of flowable or powdered bulk materials is provided which includes the combination of a flexible and collapsible bulk bag bottom component having an encircling first side wall, a bottom end with an opening therethrough through which contents are discharged connected about its periphery to a bottom end of said first side wall and an open upper end opposite said bottom end and a flexible and collapsible bulk bag top component having a top end, an opposite open lower end and an encircling second side wall connected about the periphery of the top end which is separably receivable within and generally complementary to the first side wall of the bag bottom component wherein the top and bottom ends and first and second side walls define an interior stoarage space therebetween for flowable granular or powdered bulk material with the second side wall being adapted to be in firm engagement with the first side wall when the storage space is at least partially filled.