Abstract: A method for converting power includes charging an inductor by coupling the inductor to a voltage source for a predetermined amount of time. Thereafter, the inductor is discharged by coupling the inductor to a ground until the current flowing through the inductor equals zero. A method for detecting a zero current flowing through the inductor includes coupling the inductor to a transistor and comparing the output of that transistor to a transistor coupled to ground.

Abstract: A power converter circuit having an inversely inductively coupled structure is disclosed. The inversely inductively coupled structure having a primary coil and a second coil wound around a core. As such, primary magnetic flux lines are generated by a primary alternating current flowing through the primary coil and secondary magnetic flux lines are generated by a secondary alternating current flowing through the secondary coil. The result is a mutual inductance of the primary coil and the secondary coil. The primary magnetic flux lines flow through the core in a direction diametrically opposing a direction in which the secondary magnetic flux lines flow through the core. Consequently, the flux swing within the core is minimized.

Abstract: A signal translating circuit is operable on applied input signal through recurring cycles of conduction and non-conduction of a junction type transistor in response to current transfers between inductors in collector and base circuits through an internal conduction path of the collector-base junction. The inductor in the collector circuit is connected to receive the input signal, and bias circuitry connected between the base and emitter receives the input signal for powering cyclic operation at a frequency determined in part by the values of inductance in the base and collector circuits. Output utilization circuitry produces output voltages of opposite polarity from oscillator output pulses of predominantly one polarity.

Abstract: Voltage stabiliser for electrical energy transportation and distribution applications, which consists of one or several electromagnetic devices of transformer type which, at discrete intervals, regulates the output voltage that reaches the consumer, taking the form of a transformer with a dual or quadruple primary winding and a simple secondary winding, the simple winding being able to be positioned before or after the parallel branch, the performance of the equipment remaining the same.

Abstract: A system for supplying power to a load connected to a power supply network, to achieve improve operating. the invention provides for the load to be connected via an inductive element, such as a duplex inductor, to the electrical supply network and to an energy store. With the inductive element having the same turns ratios, the impedance between the electrical power supply network and the energy store is greater by a factor of about 4 than that between the load and the power supply network or the energy store.

Abstract: To improve the performance of an inductive coupling system, the magnetic coupling between the primary (4) and secondary (8) windings is increased by adding auxiliary windings (26,28) on the primary (2) and/or secondary (6) yokes of the assembly near the air gap (18) between the yokes. Capacitors (30,32) are connected to the auxiliary windings (26, 28) which, together with the inductance of the auxiliary windings, resonate at the operating frequency of the primary AC voltage (Vp). The effect is an improved magnetic coupling between the primary and secondary windings (4, 8) without increasing the size of the magnetic assembly.

Abstract: An induction heating power supply is disclosed. It includes a power circuit having at least one switch and a power output. The output circuit includes an induction head. The output circuit is coupled to the power output. A controller has at least one feedback input connected to the output circuit, and has a control output connected to the switch. The controller predicts the switch zero crossing and preferably soft switches the switch. Current feedback is obtained from a coil placed between the bus bars. Each bus bar is comprised of multiple plates to increase current capacity.

Abstract: A technique for powering telephone lines using an unbalance current source and current sink; and a technique for improving attenuation/frequency distribution and return loss (impedance matching) of transformer-coupled wire-line communications circuits by using secondary series capacitance and an AC current pump signal source; and a generation of ringing voltage as positive voltage pulses with respect to a negative power supply voltage; and a technique for removal of AC power ripple by using an active linear floating filter for the purpose of powering telephone line circuits, and a technique for injection of real time tone samples into T1 transmissions circuits by use of a T1 framer idle code register.

Abstract: A power distribution network including a voltage support transformer is disclosed which uses the fault current from a line of the power distribution network in which a fault condition exists to support or stabilize the voltage across one or more other lines of the network connected to the same bus and seeing the same source impedance, to maintain the voltage in those lines substantially at the pre-fault levels. The voltage support or stabilization in the unfaulted line is based upon a current change due to the impedance change in the faulted line caused by the fault.

Abstract: A fluorescent lamp ballast utilizes a single a transformer for providing both tank inductance and current mode feedback to the ballast driver circuitry. The transformer has an "EE" core with inductor windings on the center legs and gate windings on one of the outer legs. The center leg is gapped to avoid magnetic core saturation and to adjust inductance to a desired value. Coupling can be adjusted further by gapping one or the other of the outer legs.

Abstract: A method and system for controlling the output current of large, low-voltage, DC power supply which includes at least one transformer primary by controllably switching an AC power line voltage to the primary as a function of actual and desired output currents. SCRs are used to switch, using phase control, the AC primary voltage to the transformer(s) of the power supply in order to control the output current. Given the incoming power line voltage, the current value from the previous power line cycle and the desired current for the present cycle, the function is used to find the SCR firing angle to attain the desired output current in the present power line cycle. Actual measurements of output current and power line voltage are used to modify the function to reflect changes in power line voltage and/or circuit impedance to obtain a modified function.

Abstract: A high-voltage pulse generating circuit of a charge transfer-type comprising a main capacitor for storing input energy and at least one magnetic pulse compression circuit comprising a saturable reactor, a saturable reactor on the side of a load comprising an energy recovery winding connected to the main capacitor via a rectifying element for returning unconsumed pulse energy from the load to the main capacitor. This circuit is suitable for an electrostatic precipitator.

Abstract: A voltage converter for traveller's uses includes: a 50 watts (0-50 W) transformer for converting an input voltage of 220 VAC to an output voltage of 110 VAC for normally powering a load of 50 watts or less; a 1600 watts (50-1600 W) transformer for converting an intput voltage of 220 VAC to an output voltage of 110 VAC for powering a load ranging from 50 watts to 1600 watts; and a sensing control circuit operatively sensing an output load having a power rating larger than 50 watts (50 W to 1600 W) for operatively actuating a relay for automatically switching an output terminal of the 50 watts transformer to the output terminal of the 1600 watts transformer for preventing burning or damaging of the output load connected with the voltage converter and for protecting the voltage converter itself.

Abstract: In a power supply apparatus for a load such a toroidal core testing apparatus, an input current is supplied to the load, and an output voltage of the load is obtained. A current corresponding to one part of the output voltage is negatively fed back to the input current.

Abstract: A universal phase-controlled reversible power converter having one transformer with multiple windings (i) couples a fixed d.c. voltage to an associated transformer winding through a fixed port having switches controlled for switching by fixed-phase signals, and (ii) couples any number of voltages having any waveform(s) whatsoever each to an associated transformer winding each through an associated variable port that has a filter with an inductor and controllable switches. Variable-phase switching control signals control the variable ports to produce any desired three-state demodulated waveform. A three-state demodulated waveform is filtered to present (i) a corresponding counter emf of any desired waveform to an input source or power, or (ii) any desired output waveform to a sink of power. Controllably producing the counter emf as a picture-of-the-line-input-voltage makes the load factor of the power converter, and all its loads, unity.

Abstract: To produce a high current carring inductor with a high inductance value in space normally too small, a transformer is chosen which meets space requirements and has a primary winding of sufficient current capacity, but too little inductance. A bidirectional current source drives the secondary winding under control of a feedback circuit in response to sensed primary winding current to effectively multiply the primary winding inductance.

Abstract: In a power supply apparatus for a load such a toroidal core testing apparatus, an input current is supplied to the load, and an output voltage of the load is obtained. A current corresponding to one part of the output voltage is negatively fed back to the input current.

Abstract: An inductive component for universal use in any electrical/electronic circuits, whose coefficient of self-induction (L) is independent of the signal, is constant, electrically controllable and can be varied significantly. The component (10) comprises two mutually independent, identical ring-shaped and self-contained ferro-magnetic cores (11, 12) which individually carry the partial windings (15.1, 15.2) of an induction winding (15) and jointly carry a control winding (17). The direction of coiling of the windings (15.1, 15.2, 17) is such that the magnetic fields produced by currents through the windings are mutually weakened, but in the other core (12) they are reinforced. The component (10) is connected via its induction winding (15) to a controlled circuit (25), and via its control winding (17) to a controlling circuit (27), or forms with its windings (15, 17) an element of this circuit (25, 27).

Abstract: A variable transformer, reactor having a core combining at least two complete core elements wiht a common yoke; primary winding divided into two independently fed sets of phase coils wound in opposite direction, arranged on symmetrical legs of core elements and separated by the common yoke; secondary winding with each phase coil divided into two wound in opposite direction portions carried by symmetrical core legs, adjacent to the primary coils and separated by common yoke. The secondary short-circuited reactor winding is reduced to at least one close loop member with loop portions separated by the common yoke. The single, polyphase apparatus has at least one primary coil per set that includes a controllable device in circuit relation therewith to enable control of one primary coil relative to the other, either in current magntidue or in current phase shift. The controllable device being either a silicon control rectifier, triac or transistor.

Abstract: A resonant power converter is disclosed which is constructed on an integrated magnetic core, with primary, secondary and tertiary windings occupying separate legs of the core. The tertiary winding is connected in a resonant circuit and induces a flux in the primary leg that causes the primary winding current to assume the shape of a series of generally sinusoidal pulses. Primary winding switching can thus occur at zero primary current between pulses, thereby eliminating prior interference problems. Furthermore, the converter can be operated in a pulse width modulated mode to accommodate for varying output load levels without the problems of low frequency operation encountered by prior frequency modulated resonant converters.

Abstract: A method and apparatus for effecting periodic current reversal in metal electro-deposition processes are disclosed. By using a circuit in which the current always flows in the same direction through a filter reactor, regardless of the current flow through the electro-deposition cell, faster reversal switching times are obtained. The overshoot and AC ripple encountered on current reversal are also decreased.

Abstract: A switching mode power supply provides a D.C. output voltage having a value related to the duty cycle of the supply's controlled oscillator produced signal. The inventive shutdown circuit inhibits operation of the supply if the duty cycle increases to a value indicative of failure of the supply to produce a minimum desired output voltage. Operation of the supply is inhibited for a predetermined shutdown interval following which a restart cycle deactivates the shutdown circuit for a period to allow the supply to attempt to establish its desired output.

Abstract: DC to DC converter having DC input and DC output, a first switching element to repetitively connect and disconnect the DC input to an inductance winding connected through the first switching element. A source of pulse width modulated signal provides a control signal based on the detected output voltage of the converter. A second detector which detects a variation in the output load. A second switching element which controls the inductance of the winding is actuated based on the second detected signal.

Abstract: A power converter utilizes an inverter operating at a frequency near 30 kHz to produce an RF voltage which is divided by a reactive voltage divider, one portion of the divider including a saturable reactor having a control winding which is driven by a negative feedback current from a level sensing circuit connected to the converter output. DC voltage is provided by a bridge rectifier and filter connected across the saturable reactor. The circuit is especially useful for supplying electrical power efficiently to instrumentation on multikilovolt transmission lines where a transformer cascade is used to conductively isolate apparatus operating at the potential of the transmission line from a ground level power source.

Abstract: An apparatus for stimulating and controlling the contraction of muscles includes conductive electrodes for contacting spaced-apart locations on the body between which are the muscles to be exercised. The electrodes are connected to a signal supply circuit which includes a pulse generator, a modulator circuit, a push-pull amplifier, a current control circuit and a transformer, the primary winding of which is driven by the amplifier and the secondary winding of which is connected to the electrodes. A second, lower repetition rate, pulse generator can be included to modulate the output so that signals are provided in spaced groups of pulses. The controlled current output is adjustable and monitored by a meter. A counter for counting pulse groups is included.