Abstract: An AC uninterruptible power source is disclosed that provides multi-phase wer output signals for actual use and a selectable single phase power output signal for use in testing. The AC uninterruptible power source further comprises at least one battery. The single phase output signal is connected to a dummy load by means of a power switch of the break-before-make type. The invention further includes the dummy load as preferably having metering capabilities to measure the frequency, current, and voltage parameters of the single phase output signal. The arrangement of the present invention allows for the single phase output to be mated to the dummy load without the need of removing input power to the AC uninterruptible power source so as to reduce, or even eliminate, transient caused failures to the AC uninterruptible power source and to its sensitive load equipment which the power source services.

Abstract: An ac electric drive system includes a bidirectional power semiconductor interface between a battery, or an auxiliary energy storage device, and a power inverter for boosting an input dc voltage and for decoupling the dc link voltage from the input dc voltage such that the dc link voltage is substantially independent of the input dc voltage and the parameters of the battery or energy storage device. The input dc voltage is controlled to maximize efficiency along predetermined torque envelopes.

Abstract: An electric cooking apparatus includes a single power converter section for converting power supplied from an external AC power source. A heating-energy radiator section receives the converted power from the power converter section and radiates heating energy to a heating chamber. A battery is also provided for supplying power to the power converter section such that a sum of the power from the external AC power source and the battery is converted by the power converting section when an instantaneous voltage of the external AC power source is smaller than a predetermined voltage level, which predetermined voltage level is smaller than a maximum instantaneous voltage of the external AC power source.

Abstract: Improvements to a power supply backup circuit used to backup the operation of a radio device or the like when a power supply therefor is interrupted. A reverse current preventing diode is connected such that its anode is connected to the junction point of a DC power source and a voltage stabilizing circuit and such that its cathode is connected to the stabilizing circuit. A transistor is provided which has a collector connected to the cathode of the diode, an emitter connected to one end of a capacitor, the other end of which is grounded, and a base connected to a DC power source via a first resistor, and which has a second resistor connected across the base and emitter thereof. A third resistor is further connected across the collector and emitter of the transistor.

Abstract: In order with a low degree of equipment complexity to convert two alternating-currents of 16 2/3 Hz of two separate single-phase generators (G1, G2) of approximately the same power into a three-phase current with 50 Hz, the single-phase generators are connected via a SCOTT transformer (Tr1) to a rectifier (SR1) of a converter with a direct-voltage intermediate circuit (3-6). The direct current transmitted through the direct-voltage intermediate circuit is transformed into three-phase current by two inverters (SR2, SR3) connected in series, and supplied to a national power system (10) via power transformers (Tr2, Tr3). The two single-phase generators (G1, G2) are controlled by one generator voltage controller (42) in each case, which affects the excitation of the single-phase generators (G1, G2) via a field rectifier (43), at the same amplitude of their generator voltages (u1, u2). Moreover, the single-phase generators (G1, G2) are controlled at a phase shift of their generator voltages (u1, u2 ) of 90.degree.

Abstract: The invention relates to a converter which can operate as a rectifier to rectify alternating current into direct current running in one direction (for example to charge batteries) or a converter where DC (from the batteries) can be converted to AC and supplement AC power, for example to supplement an alternator output in peak load conditions. The converter comprises a uni-directional electrical energy source (battery) and a bi-directional energy source (small battery bank connected for reverse direction current flow, capacitor or fuel cell) which is capable of initiating an alternating current when controlled by thyristors fired in sequence and with such periods that a sine wave can be simulated. The switches are controlled by a thyristor trigger logic current control unit which may for example be a micro processor.

Abstract: A power supply circuit includes a series circuit, made up of a current feeding element and a charge storage element, which is coupled in parallel to the output of a power supply source. The power supply circuit also includes a first diode, connected to one terminal of the current feeding element, for feeding a first current from the power supply source to a load, and a second diode, connected to the other terminal of the current feeding element, for feeding a second current from the charge storage element to the load. The charge storage element can be fully charged-up with the voltage coming directly from the power supply source.

Abstract: This regulating system for an array of solar panels or the like consists of a tap connection into the array, and a boost switching regulator connected to the tapped array. The tap connection divides the array into first and second portions, and the switching regulator is connected so that its power-input terminals are across only one of the two portions of the array. The power-output terminals of the switching regulator are connected across the load (i.e., across the entire array), and the sensing or feedback terminals of the regulator receive a signal which acts as a measure of voltage or current at the load.Boost regulators do not dump overvoltage into a dissipative load; hence the invention prevents local heat generation and resulting spacecraft heat-balance problems of conventional dissipative regulators.

Abstract: The present invention relates to supplying a load either from a direct-current source or from an alternating-current source. The power unit, according to the invention, is characterized in that it consists of a single conversion unit (CV) having unidirectional semi-conductor power components forming switches (I1, I2, I3, I4) controlled in appropriate fashion by a logic control in such a manner as to ensure the functioning of the conversion unit (CV) either in a chopper mode, or in a rectifier mode when the load functions to draw power, or to ensure energy regeneration when the load functions in a generating mode. The present invention has application particularly for supplying direct-current motors used in dual-current railroad locomotives.

Abstract: A circuit arrangement comprises two feed circuits which are connectible to a load with mutually opposite polarity. The circuit arrangement avoids mechanical contacts in the load circuit, at least with respect to one feed circuit. This is achieved in that switches, provided for the activation at at least one of the feed circuits, are disposed outside of the output circuit and in that a transistor is disposed between such a feed circuit and the load, this transistor being conductive given an activated feed circuit and being inhibited given a deactivated feed circuit. The circuit arrangement can advantageously be employed in remote feed devices of communications transmission device for the purpose of optionally feeding a remote feed section with a remote feed current or with a fault locating voltage.

Abstract: A circuit for combining independently controlled AC and DC voltages in which AC and DC voltages are respectively applied to different inputs of a first amplifier, its output is connected to a first output terminal, the DC voltage is applied to the input of a second amplifier, its output is connected to a second output terminal that is grounded for AC, a voltage divider is connected between said output terminals and the gains of the amplifiers for DC are the same.

Abstract: A load control circuit having an input terminal adapted to receive any one of a number of different input voltage signals including signals of at least first and second type. These signals may be, respectively, DC and AC input signals. Control circuits are provided for operation of the load from the input voltage signal. This control circuit includes at least first part responsive only to said input voltage signal being of first type for coupling said signal of first type to the load, and a second part responsive only to the input voltage signal being of second type for coupling the signal of second type to the load.

Abstract: An electric power unit capable of operating from different AC input power source voltages in which changes in the AC input voltage are compensated for automatically and rapidly. The power unit includes a rectifier circuit having both a voltage-multiplying rectification function and a non-voltage-multiplying rectification function. A switching circuit is provided for selecting as the operating rectification function one of the voltage-multiplying rectification function and the non-voltage-multiplying rectification function. A switching control circuit, operating with the AC input to the rectifier circuit as a reference potential, controls the switching circuit according to the value of the AC input voltage. An auxiliary power source establishes a voltage for powering the switching control circuit before the operation of the switching control circuit to select the rectification function is effected.

Abstract: A solid state relay provides for a discontinuous transfer contact function. The solid state relay includes a first field effect transistor (FET) in a first switch, and second and third FETs in a second switch. The first and second FETs are each connected with AC responsive bias circuits for biasing the respective FETs into a non conductive condition. A control circuit operates the first and second switches to provide a transfer contact function. In a switching transition between a supply of a talking battery via the second switch, to a telephone line, to a supply of a ringing battery line via the first switch to the telephone line, the third FET is operated to increase impedance between the talking battery supply and the second FET, to permit AC voltage from the ringing battery supply to bias the second FET OFF.

Abstract: The current from an external AC power source is rectified to charge a DC battery and conduct current therethrough in series with a load during one-half of each power cycle of the external source. During the other half of each cycle, current is conducted through the load by discharge of the battery through a transistor that is switched to its conductive state by a phase control transformer connected to the power source.

Abstract: A portion of the apparatus, which requires low voltage DC energy for its energization, is connected in series with an SCR between a single pair of input or energizing terminals. A series RC circuit is connected across the SCR, and the junction within this series circuit is connected through a zener diode to the gate of the SCR. When low voltage DC is applied between the input terminals, it turns on the SCR continuously and effectively appears across the noted apparatus portion to properly energize the latter. When high voltage AC is applied between the same input terminals, it turns on the SCR for only a predetermined part of each cycle of the AC. This part is made to be such that the resulting voltage across the noted apparatus portion is effectively the same when the high voltage AC is applied between the input terminals as it is when the low voltage DC is applied between the same input terminals.

Abstract: A wrist carried instrument includes a rechargeable electric energy source for providing power to the instrument. The energy source is recharged by a pair of generators, both operatively coupled to the source and generating complementary recharging currents from different physical phenomena. The first generator may be a photo-electric cell generating a recharging current in light such as exists from the sun in summer, while the second generator may be a thermoelectric element generating a recharging current from a temperature gradient such as exists in the dark or winter.

Abstract: In an electric power converting apparatus utilized to convert the power of a storage battery into an AC voltage, step up the AC voltage by use of a step up transformer and rectify the secondary voltage of the transformer to directly operate a DC driving motor of a car or an AC motor through an inverter, a rectifier and an inverter are provided to energize the secondary of the transformer from a commercial source and another rectifier is provided on the primary side of the transformer to charge the storage battery.

Abstract: A parametric energy coupling system for providing uninterruptible a-c power o electrical loads. In a normal mode, a parametric transformer couples a-c line power directly from an a-c power source to a load. Upon a power outage occurrence, an inverter is energized whereby a-c power is generated from a d-c source and applied to the load.

Abstract: Two sources of current are applied to a load. One source supplies a constant current which is at least equal to the maximum current to be supplied to the load in one polarity. The second source is in opposition to the first source and is capable of being controlled from zero to a value at least double the value of the constant current. A voltage feedback circuit in combination with a bipolar control signal provides a bipolar voltage across the load having maximum positive and negative voltage excursions equal to the control signal times the feedback circuit gain and current in either direction having a maximum value substantially equal to the constant current value. In this manner a high voltage regulated bipolar voltage can be controlled across a load using one controlled unipolar device while providing class A operation, that is, without cross-over distortion. An important feature of the invention is the positive and negative limiting of both load voltage and load current.

Abstract: A pulse width modulated motor control system in which the power supplies for forward and reverse operation for the motor are provided to supply electric energy at different levels. The control signals for the motor are provided in such a manner that the average energy of unbalanced pulse periods is the same, but the potential level differs by a substantial amount. Energy storage may be provided for in conjunction with the lesser of the two power supplies to assist in a rapid reversal, stop or shaft positioning of the motor.