Abstract: A zero-current switching converter converts power from an input source for delivery to a load. In the converter, a switch opens and closes at times of essentially zero current to enable energy transfer back and forth between said input source and said converter. A controller is connected to control the switch to initiate, during a first portion of each of a succession of converter operating cycles, forward energy transfer from said input source; and in at least some of said converter operating cycles, also to initiate reverse energy transfer to said input source at times not contiguous with said first portion.

Abstract: A switching circuit is provided to process a DC voltage and apply a low frequency AC voltage, having a trapezoidal waveform, to a co-axial cable transmitting the low frequency AC voltage to a load which may be powered by the low frequency AC voltage as well as a DC voltage. In one specific embodiment two of the switches are connected as part of buck regulation circuits to serve a dual purpose of polarity switching and regulation.

Abstract: A zero-current switching converter converts power from an input source for delivery to a load. In the converter, a switch opens and closes at times of essentially zero current to enable energy transfer back and forth between said input source and said converter. A controller is connected to control the switch to initiate, during a first portion of each of a succession of converter operating cycles, forward energy transfer from said input source; and in at least some of said converter operating cycles, also to initiate reverse energy transfer to said input source at times not contiguous with said first portion.

Abstract: An apparatus and method for generating a low frequency AC signal such as a ringing voltage signal for a telephone subscriber interface unit or the like. The apparatus comprises an oscillator which drives a pair of counters whose outputs differ by a desired low frequency. The output of the first counter is fed to a controlled current source so as to excite a resonant tank circuit and thereby provide a high voltage sinusoidal signal. The output of the second counter drives a switch which samples the high voltage sinusoidal signal. An alias frequency is thus generated which is filtered by an output capacitor. The method comprises steps which follow directly from the above-described apparatus.

Abstract: The capacitor coupled converter (CCC) is a DC-DC converter which produce a DC source as the output. It has two input terminals for connection to a DC voltage source, two output terminals for connection to a load, and a plurality of circuit control terminals for receiving a plurality of control waveforms. The basic elements of the CCC are two switches connected in series across the input terminals. An inductor in series with a transformer is connected to the junction of the two switches. Two capacitors with parallel diodes are connected across the input DC voltage source. The junction between the two capacitors is connected to one of the primary terminal of the transformer. The secondary terminals of the transformer is connected to an AC-DC converter, typically two diodes which rectify the AC to DC. The DC is then filtered by an inductor-capacitor filter. During operation, the two switches periodically and alternately open and close.

Abstract: Apparatus and methods for AC power regulation primarily intended for inductive loads (e.g., fluorescent lights, motors, etc.) which provide substantial reduction in power consumption while also providing a leading power factor, reduced harmonic distortion, reduced crest factor and reduced noise. The system is self-adjusting for a wide range of loads and can reduce power consumption by 25 percent in lighting loads while producing minimal reduction in light output. The system utilizes a Triac (32) and parallel capacitor bank (58) with the load (22). The Triac (32) is turned on in response to a near-zero differential voltage measured across the Triac (32) and is turned off near the peak of each AC half cycle by shunting current around the Triac (32). The capacitor (60) absorbs the inductive turn-off voltage spike caused by the collapsing magnetic field in the ballast at the instant of Triac turn-off.

Abstract: A DC voltage polarity switching circuit includes four switches connected in a bridge configuration. Switches in opposing legs are paired with each other and turned on and off in alternate phases to deliver a low frequency alternating signal having a trapezoidal waveform to a co-axial cable load. Circuitry is included to control the slew rate when the output signal transitions from one polarity to the other. Also, turn on of a switch in one phase is delayed during turn off of a switch in the end of the interval of presently conducting switches in one phase.

Abstract: An MOS transistor Q3 operates in a diode mode, and applies a voltage which is lower than a power supply voltage Vcc by an absolute value of its threshold voltage to the gate of an MOS transistor Q1. MOS transistor Q1 operates in a saturation region, and a supplies current which is in proportion to the difference between the threshold voltages of MOS transistors Q3 and Q1 to an output node 2. An MOS transistor Q4 also operates in a diode mode and applies a voltage equal to its threshold voltage to the gate of MOS transistor Q2. MOS transistor Q2 operates in a saturation region, and discharges current which is in proportion to the difference between the gate-source voltage and the threshold voltage. The currents flowing through MOS transistor Q1 and through MOS transistor Q2 are equal to each other. Accordingly, the dependency upon temperature of the threshold voltages is canceled, and thus an output voltage V0 with extremely low dependency upon temperature can be obtained at output node 2.

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: The object of the prevent invention is to provide a solar energy system of simple construction capable of utilizing the photovoltaic source always at a high efficiency without being affected by environmental changes or yearly declination of photovoltaic cell, etc.

Abstract: A resonant, snubber-based, soft switching, inverter circuit achieves lossless switching during dc-to-ac power conversion and power conditioning with minimum component count and size. Current is supplied to the resonant snubber branches solely by the main inverter switches. Component count and size are reduced by use of a single semiconductor switch in the resonant snubber branches. Component count is also reduced by maximizing the use of stray capacitances of the main switches as parallel resonant capacitors. Resonance charging and discharging of the parallel capacitances allows lossless, zero voltage switching. In one embodiment, circuit component size and count are minimized while achieving lossless, zero voltage switching within a three-phase inverter.

Abstract: A power supply is disclosed which is compatible with modern thin film technology which has an overall size compatible with modern miniaturized electronic components. Input power having an oscillating component in the 50/60 Hz 120/220 volt range is immediately switched to high frequency current exceeding 100 KHz and preferably switched with a frequency in the megahertz range. The switched current, otherwise unaltered from its current having an oscillating component, is then transduced in voltage at a thin film transformer, passed through thin film mounted electronic components for rectification and filtering. A regulator circuit modifies the semi-conductor switch duty cycle to control the rectifier output voltage. All transformer, rectifier, and filter components are of thin film variety and mounted to attain efficient heat dissipation together with size reduction comparable to the powered components driven by the power supply.

Abstract: A power supply apparatus and method for supplying direct current power to low and medium voltage DC loads wherein a multi-phase transformer having multiple secondary windings provides multi-phase power to multiple power cells, each of which have a single DC output and are controllable by a modulation controller. The primary and secondary windings in the power transformer may be star- or mesh-connected; the secondary windings may be shifted in phase. Because the power cells can be connected in series, the maximum output voltage for each cell may be less than the maximum line-to-line voltage. The power cell output can have variable DC voltage and current which can be controlled using pulse-width modulation techniques. AC input power is converted to DC output power for each power output line. Output power modulation can be produced by interdigitating a selected number of carrier signals so that harmonic components reflected back to the input are attenuated.

Abstract: A failure-free power source device memorizes the history of errors of a commercially available power source, monitors the stability of the power source on the basis of the history, directly outputs, when the power source remains stable for more than a predetermined period of time, an AC input as an AC output, and releases, when an error occurs in the power source, energy stored in an accumulator until a predetermined period of time expires to thereby output it as an AC output via an inverter.

Abstract: A control system for a pulse-width modulation controlled power converter composed of self-turn-off devices. The control system includes a voltage command value generator for the power converter, a carrier wave generator and a circuit for correcting at least one of the voltage command value and the frequency of the carrier wave to generate as a corrected voltage command value and a corrected carrier wave. The control system further includes a gate pulse signal generator for receiving a first signal and a second signal and for comparing the first and second signals to generate gate pulse signals to the self-turn-off devices for controlling the power converter based on a comparison result. The voltage command value is taken as e (-1.ltoreq.e.ltoreq.+1), and a level setting value is taken as E.sub.a (0<E.sub.a <1). The gate pulse signal generator receives the voltage command value and the carrier wave as the first and second signals when -E.sub.a .ltoreq.e.ltoreq.+E.sub.a.

Abstract: A light dimmer is provided in which semiconductor power devices for each of the polarities of an alternating current supply are coupled between the alternating current supply and a lamp load. In the course of varying average power supplied to the lamp load, the semiconductor power devices transition between an initial one and a subsequent other of substantially conductive and non-conductive power conditions. The duration of the transition by the power device is increased beyond the minimum possible duration to reduce generated EMI. Methods of restoring each power device to its initial condition, including during a subsequent half-cycle, are described.

Abstract: A regulated charge pump is provided to boost an amount of voltage while minimizing the well voltage fluctuation during the operation. The charge pump includes a charge pump core which has a first transistor, a second, a third transistor and an integration circuit. The first transistor has a first current electrode for receiving the first power supply voltage and a second current electrode coupled to the first terminal of the charging capacitor. The second transistor has a first current electrode coupled to a second terminal of the charging capacitor, a control electrode and a second electrode for receiving a second power supply voltage. The second transistor is proportionately conductive during the first predetermined time period. The third transistor has a first current electrode for receiving the first power supply voltage, and a second current electrode coupled to the second terminal of the charging capacitor. The third transistor is conductive during the second predetermined time period.

Abstract: An integrated current reference circuit provides a current output with a predetermined temperature coefficient, suitably zero, to provide constant current over temperature variations. The circuit is formed of only Field Effect Transistors (FETs), allowing the circuit to be implemented using conventional CMOS fabrication techniques. A current mirror provides a reference current in both branches of the circuit. The output of the current mirror is coupled to a circuit providing an imbalance in resistance between the two branches, and an offsetting imbalance in voltages between the two branches, resulting in a reference current that has a predetermined temperature coefficient. An output current is provided which is proportional to the reference current and thus has the same temperature coefficient as the reference current.

Abstract: A power supply device includes a series arrangement of an inductance (3), a switching device (4) clocked by a control circuit (12), and a current measuring impedance (5), which series arrangement is arranged between two terminals (1, 2) to which a supply voltage (Ue) can be applied. A voltage (Um) appearing across the current measuring impedance (5) is applied via an input resistor 17to an input (18) of the control circuit (12) to control the switching device (4), a capacitance (19) being in parallel with the input (18) of the control circuit (12).A diode (20) is arranged in parallel with the input resistor (17), dimensioned in such a manner relative to one another that the diode (20) becomes conductive only when the Voltage (Um) across the current measuring impedance (5) exceeds a given limit value. Also, the ohmic resistance of the diode (20) together with the capacitance (19) forms a smaller time constant than the input resistor (17) with the capacitance (19).

Abstract: To provide for an improved operating characteristic of a direct-current transmission between static converters (5a, 5b) of a high-voltage direct-current transmission installation, a method and an arrangement (1a) are provided in which the static converters (5a, 5b) are in each case supplied with control signals (.alpha.a, .alpha.b) which are assembled from part-control signals (.alpha.i to .alpha.n). The closed-loop control devices (11a, 11b) preceding the static converters (5a, 5b) are constructed as vector controllers in this arrangement.