Abstract: A power supply with multiple outputs including at least two power converters, each with multiple outputs, a first output of a first power converter being connected in parallel with a first output of a second converter to provide a first load with current. The power supply further includes a first regulating circuit for delivering to each power converter a command signal that is a function of the current delivered to the first load. The power supply also includes at least one other regulating circuit for delivering to an output regulator (postregulator) connected between each power converter and a load other than the first load, a command signal which is a function of the current delivered by each converter output to the load other than the first load.

Abstract: In the load flow calculating method of the present invention, a Jacobian matrix for reactive power with respect to voltage is made to coincide with a part of a Jacobian matrix for effective power with respect to phase by introducing variables of the quotients of differences between effective power and reactive power flowing through each node and specified values divided by the square of voltage on each node, whereby the need for triangular factorization of the Jacobian matrix for reactive power with respect to voltage is eliminated, and, at the time of calculating a voltage correction amount, the voltage correction amount is compensated by the use of the product of a Jacobian matrix for reactive power with respect to phase and a vector of phase correction amount, and by virtue of the needlessness of triangular factorization of the Jacobian matrix for reactive power with respect to voltage and nonnecessity, at the time of calculating the voltage correction amount, for calculating discrepancy of reactive power

Abstract: A multi-phase switched reluctance motor is driven from a tow-point d.v. supply (11) in which capacitors (12) and (13) are provided across the supply with their common point (14) constituting a third power supply point. The load windings W.sub.1, W.sub.3, W.sub.5 and W.sub.2, W.sub.4, W.sub.6 are connected in two different load circuits connected across the different capacitors. In order to prevent the voltage of the third point wandering because the currents in the the two load circuits are not the same, control means (21) can control the distribution of current between the various load windings by appropriate control of semi-conductor switches in the various load circuits.

Abstract: A controller for controlling an electrode boiler steam humidifier, of the type operable from a source of polyphase alternating current, is provided. A plurality of current loop transformers, coupled to the boiler electrodes, sense the individual currents drawn in each phase of the polyphase alternating current. A plurality of full-wave bridge rectifiers individually couple the secondaries of the current lube transformers to the input of a voltage amplifier such that the output of the amplifier is indicative of the highest of the currents sensed in each phase of the boiler electrode current. When the output of the voltage amplifier exceeds a predetermined threshold, a control effect is produced such that operation of the humidifier is controlled in accordance with the highest of the individual phase currents drawn through each of the boiler electrodes.

Abstract: A multisource power supply for supplying a plurality of various power levels from a common AC source, including a plurality of switchable power source modules, a power line conditioner PLC including a high voltage switching supply and logic level supply coupled between the AC source and each of the power source modules, a common controller coupled to each of the power source modules for setting and monitoring the output of each of the modules, each of the modules being removable from the multisource power supply, and an interlock control responsive to removal of any of the modules for disabling the high voltage switching supply.

Abstract: An inverter control system for selectively operating on one of an inverter and backup power source to supply a load current comprises a PLL circuit which includes an integrating amplifier and is operative to synchronize the inverter operation with the voltage of the backup power source. When the power supply to the load is switched from the backup power source to the inverter, a.c. switches for the switching operation are controlled so that both the backup power source and inverter are active simultaneously for a certain period, and during the parallel operation the integrating amplifier is supplied with a reference signal which operates on the inverter to increase its shared load current.

Abstract: A high integrity multiple output power conditioner operating from redundant dc sources utilizes circuits to combine the sources to share a load and provide source isolation in event of component failure in any one of plural converters employed. Multiple ground planes permit high integrity checking of individual operation of multiple power converters employed in the system.

Abstract: An electrical distribution system has parallel connected generators powered by variable speed engines. Loads connected with each generator are interconnected through an electrical distribution bus. Constant speed drives have inputs connected with the engines and outputs directly connected with the generators. The connections between the constant speed drive outputs and the generators are characterized by the absence of overrunning clutches used in prior systems. An improved electrical protective circuit senses a flow of electrical power from the distribution bus to a generator, driving the generator as a motor. If the power flow to the generator is excessive, the bus tie breaker is opened disconnecting the generator from the bus.

Abstract: A current-drive circuit (FIG. 1) is provided to drive each of forty electrodes 41. When selected, the circuit forces line 27 to a level of drive voltage Vdr minus a current-level reference voltage Vlev. A constant current is produced across resistor 25. Line 27 is connected through resistor 29a to line 27a, which is the same point in the current-drive circuit of the adjoining electrode 41a (FIG. 3) on one side of electrode 41. Line 27 is similarly connected through resistor 29b to line 27b, which is the same point in the current-drive circuit of the adjoining electrode 41b (FIG. 3) on the opposite side of electrode 41. Selection of the drive circuit also connects line 27 to the associated electrode 41. An unselected drive circuit for an adjoining electrode, such as the one connected to drive electrode 41a, has line 27a floating to the level dictated by Vdr through its resistor 25a, while its electrode 41 is disconnected.

Abstract: A current-drive circuit (FIG. 1) is provided to drive each of forty electrodes 41. Voltage at the electrodes 41 is monitored on line 49 as a control-input to a voltage-regulator circuit (FIG. 2), to produce the drive voltage Vdr. Vdr minus a current-level reference Vlev is applied as the input of a differential amplifier (transistors 3, 15, 51 and 53), thereby applying Vdr-Vlev on line 27. A constant current through the electrode 41 is produced across register 25. As the lowest voltage at all driven electrodes shifts, the regulator circuit (FIG. 2) shifts Vdr the same amount, employing differentially connected transistors 72 and 74, and Zener 120 to set the level of Vdr. Since most of the active elements operated within narrow limits, the circuit can be extensively miniaturized.

Abstract: A universal input-output apparatus has: a controllable source of electrical energy including at least one drive source having an output terminal and a return terminal; an electrical energy measuring device including at least one energy sensor having an input terminal connected to the output terminal of the controllable source of electrical energy; a twin leaded line having the first ends thereof connected to the output and return terminals of the drive source, respectively; and an integrity tester in the form of a zener diode connected across the second ends of the first and second leads, respectively, a first terminal connected to one of the second ends, a second terminal connected via a unidirectional conductor to the one second end and a third terminal connected via a resistive device to the one second end.

Abstract: A load control for a system comprised of a plurality of energy converters wherein the energy output of all converters is adjusted in parallel to maintain the total rate of energy output from the system equal to demand and wherein during steady-state conditions the rate of energy conversion for that converter having the lowest incremental cost is increased and simultaneously the rate of energy conversion for that converter having the highest incremental cost is decreased a like amount.

Abstract: A method and apparatus for controlling a current and/or power between interconnected power stations.A deviation from a base load in an active current or power flowing out of a power station and a deviation from a normal value in the terminal voltage of the power station are measured. A linear function of the ratio of the voltage deviation to the active current deviation is obtained, and a product of the active-current to voltage deviation function and an active current flowing out of the power station is calculated, and thus a reactive current is defined by the product.An internal generation current of the power station is controlled so as to coincide substantially with the sum of the current composed of the active current and the reactive current defined above, and other currents of the power station including the internal load current.

Abstract: A load, such as a logic network of the TTL type, is connected in parallel across a plurality of direct-current sources designed to maintain a substantially constant operating voltage. Each source includes a control unit which compares the load voltage with a reference level in order to stabilize the output voltage of an associated current generator at that level. If the generator current drops below a certain minimum value, however, a threshold sensor in the control unit raises the reference level up to an amount equaling about twice the maximum divergence possible between the reference levels of different control units, thereby ensuring that all sources contribute simultaneously to the load current.

Abstract: An electrophotographic apparatus includes a photosensitive member with a conductive layer, a photoconductive layer and an insulating layer; a variably controlled primary corona discharger for applying a charge of a predetermined potential onto the surface of the photosensitive member, a secondary corona discharger for applying a corona discharge containing a component of which polarity is opposite to that of the primary corona discharge; an imagewise exposure device for exposing the photosensitive member to an image light substantially simultaneously with the corona discharge by the secondary corona discharger, and high voltage source, for supplying predetermined high voltages to the primary and secondary corona discharger, having a high voltage transformer provided at least with a primary input coil, a secondary high voltage output coil and a tertially coil associated with a variable load impedance. An electrostatic latent image of a predetermined contrast is formed on the photosensitive member.

Abstract: A voltage dividing circuit provides an intermediate level potential or intermediate level potentials between the maximum and minimum level potentials necessary for dynamic- or scanning-driving a liquid crystal display device. The voltage dividing circuit includes at least one insulated gate field effect transistor and a plurality of resistive elements each with relatively small resistance connected in series between power source terminals. The insulated gate field effect transistor is enabled during a fixed time interval at the initial stage of one display cycle to provide drive voltage to the liquid crystal display device with low output resistance. A first dividing circuit including low resistive elements enabled by an insulated gate field effect transistor or transistors may be connected in parallel with a second dividing circuit including relatively high resistive elements which provides the intermediate level potential or potentials with the same level as of the first dividing circuit.

Abstract: A stabilized DC power outputs supply devices for providing a plurality of DC power outputs which are selectively consumed, is provided by use of a single power control circuit. A plurality of DC power outputs are taken out from the single power control circuit through rectifier circuits and low-pass filter circuits. A voltage of each of the DC power outputs is sensed by a corresponding voltage sensing circuit and is compared with a corresponding reference voltage at a corresponding voltage comparing circuit. Detecting circuits for detecting one of the DC power outputs which is being consumed are provided to apply to a control signal generator the output of one of the comparing circuits which is corresponding to the DC power output detected by the detecting circuits. The control signal generator provides a control signal to the single power control circuit to stabilize the voltage of the DC output which is being consumed.

Abstract: A power supply circuit supplies a liquid crystal energizing circuit with desired potentials for the purposes of energizing a liquid crystal display in accordance with combinations between first, second, third and reference potentials.

Abstract: A circuit for use with an oximeter system which provides constant current pulses to light-emitting diodes in a sequential and cyclical manner. The circuit maintains magnitudes of pulses in the pulse train equal to certain other pulses in the pulse train over extremes of temperature variation, voltage variation, and time duration. Each diode is energized by a series of pulses having the same magnitude, although pulse magnitudes will vary from diode to diode. Therefore, light output from one light-emitting diode remains proportional to light output from the others.

Abstract: A system for providing a desired energizing current, according to a reference current signal, to a load or group of load elements. Three phase energizing current is rectified by a plurality of controlled switching devices such as thyristors, and apparatus is provided for varying the firing angle of the thyristors in accordance with the reference current signal to regulate the resulting output voltage therefrom and thereby regulate the energizing current through the load.