Abstract: A power conversion device including, a power converter controlling a motor in variable speed control, first to second control circuits outputting first to second control signals, first to second detectors detecting a state of the power converter and outputting first to second detection signals to the first to second control circuits, a switch receiving the first to second control signals and outputting one of the control signals to the power converter, and a selection circuit outputting a changeover selection signal to the switch for outputting the second control signal instead of the first control signal, when the switch has outputted the first control signal and the first control circuit fails.

Abstract: The present invention is directed to a flexible converter. A flexible converter of the present invention may provide a desired output utilizing a variety of methods, systems and apparatus without departing from the spirit and scope of the present invention. For instance, a method may include loading an initial configuration including at least one power characteristic into a converter. The converter is suitable for providing power to an electrical device. A power output is generated having the at least one power characteristic. The power output is monitored with a comparator, the comparator suitable for measuring the at least one power characteristic.

Abstract: The present invention is directed to a flexible converter suitable for providing a routing function. A flexible converter of the present invention may provide a desired output utilizing a variety of methods, systems and apparatus without departing from the spirit and scope of the present invention. A routing apparatus may include a converter, at least one comparator and a controller. The converter is capable of providing an output supply from an input supply coupled to the converter, the output supply capable of routing between a first output and a second output. At least one comparator is coupled to the output supply of the converter, the comparator capable of measuring at least one power characteristic of the first output and the second output to a first electrical device and to a second electrical device.

Abstract: A lamp load control system that includes a lamp controller comprising an inverter generating an AC signal from a DC signal, a load coupled to the inverter, and a feedback circuit coupled to the load generating a feedback signal indicative of power supplied to the load. In one exemplary embodiment, the system also includes a command signal generator generating a command signal indicative of a preferred power output of the inverter; wherein the command signal is combined with the feedback signal to cause the controller to temporarily reduce power delivered to the load. In another exemplary embodiment, the system includes a command signal generator generating a command signal indicative of a preferred power output of said inverter; wherein the controller receives the feedback signal and the command signal and temporarily reduces power delivered to the load based on the value of the feedback signal or the command signal.

Abstract: The switched power converter comprises a first rectifier module (11-1) connected to a first capacitor (11-2) that, in turn, is connected to an excitation module (11-3) that applies a voltage to some input terminals (PT-1, PT-2) of a piezoelectric transformer (PT). A controller device (11-3-3) governs the excitation module (11-3) in order that the piezoelectric transformer (PT) works at constant frequency and regulates the power delivered to the output of the converter by enabling/disabling the voltage applied to the terminals (PT-1, PT-2). When the piezoelectric transformer (PT) is not transferring energy between its input terminals (PT-1, PT-2) and its output terminals (PT-3, PT-4), the converter output voltage is supplied by a second capacitor included in a second filter (11-6).

Abstract: A power conversion device including, a power converter controlling a motor in variable speed control, first to second control circuits outputting first to second control signals, first to second detectors detecting a state of the power converter and outputting first to second detection signals to the first to second control circuits, a switch receiving the first to second control signals and outputting one of the control signals to the power converter, and a selection circuit outputting a changeover selection signal to the switch for outputting the second control signal instead of the first control signal, when the switch has outputted the first control signal and the first control circuit fails.

Abstract: A remote control receiving device mounted on an apparatus has a switch circuit and an LED. The switch circuit is connected between a power supplied circuit of the apparatus and a power source. The LED functioning as a light receiving element receives an optical signal from a transmitting device. When the apparatus turns into a standby state based on an optical signal from a transmitting device, the switch circuit is brought into OFF by a microcomputer in the remote control receiving device. This intercept supply of power to the remote control light receiving circuit as well as the apparatus. When the LED receives an optical signal from the transmitting device, the LED outputs a electric control signal under an unbias state to turn on the switch circuit. Thereby, power is supplied to the apparatus.

Abstract: The present invention relates to a bi-directional AC/DC converter having (i) a power stage, (ii) a sourcing control circuit and (iii) a recuperation control circuit. The converter operates with a Power Factor Correction in both directions, i.e. when transferring energy from the AC mains into the DC load as well as when it is transferring energy from an active DC load into the AC mains. Smooth transition between sourcing and recuperation is possible by allowing an active load to control the output voltage until the correct control circuit begins regulation.

Abstract: The present invention provides a nonlinear adaptive voltage positioning DC-DC converter method and apparatus that enable improved voltage transient response under changing current conditions for a load with known current draw characteristics. The invention in some embodiments provides that the nonlinear adaptive voltage positioning be adaptable or configurable to a specific, known current load range that comprises less than the full current range that may be provided by the DC-DC converter, to optimize voltage transient response for a particular known load.

Abstract: A power supply adjusting circuit includes a reference voltage supplying part generating a reference voltage based on an external voltage, a plurality of internal voltage generating parts generating a plurality of respective internal voltages based on the reference voltage, and a plurality of control parts corresponding to the internal voltage generating parts, respectively, so as to be able to separately control the internal voltages.

Abstract: A method and apparatus for controlling the providing of conditioned AC power, with the conditioned AC power being capable of being provided on a continuous basis. Unconditioned AC voltage is received by transverters. The transverters convert the unconditioned AC voltage into a transverter AC output voltage. The transverter AC output voltage is monitored by current and voltage sensors. A transverter control signal is developed in response to changes in the current and voltage sensing in comparison with a reference signal. The transverter control signal then regulates conversion of the transverter AC output voltage into the desired conditioned AC output voltage. In multi-phase AC voltage systems conditioned AC voltages for each phase are provided.

Abstract: A power delivery apparatus and method which calibrates a voltage delivered from a central unit to a remote unit to compensate for losses in the supply lines between the central unit and remote unit is disclosed. The impedance of the supply lines is determined utilizing a reference voltage conducted by a calibration line, a sweep tone transmitted down the supply line, or a time domain reflectometer technique. Based upon the determined impedance of the supply lines, the voltage delivered from the central unit can be calibrated accordingly. Alternatively, the impedance can be determined and the voltage calibrated based on the measured input voltage to the remote unit or the measured power level of a signal transmitted from the remote unit.

Abstract: A hybrid diode/thyristor AC/DC converter includes a thyristor bridge (21) poled oppositely to a diode bridge (13), current through the thyristor bridge being controlled by IGBTs (30, 31). A thyristor turn-off circuit (40-42, 45-47) is responsive to turn-off of the IGBT to reverse bias the thyristors, thereby causing them to turn off. The thyristors and IGBTs are controlled (50) in response to voltage (55-57) of and current flowing (51-53) in the AC mains so as to cause the current flowing to or from the AC mains to be more nearly sinusoidal. The hybrid bridge handles application of regenerative power to the AC mains.

Abstract: The invention provides a voltage regulating device for regulating the operating voltage of a CPU in a computer system. The voltage regulating device includes a voltage identification signal regulator and a voltage identification signal bridge. The voltage identification signal regulator is controlled by a controlling signal to output a voltage identification regulating signal to the voltage converter. In this case, the voltage converter outputs the operating voltage of the CPU according to the voltage identification regulating signal. Meanwhile, a voltage monitor is used to monitor the operating voltage. When the voltage identification signal regulator outputs the voltage identification regulating signal, a voltage identification signal bridge blocks a default voltage identification signal output from the voltage identification signal setting device.

Abstract: A converter system, in particular for supplying electrical drives with direct current or DC voltage, or with alternating current or AC voltage, at a specifically matched frequency or for dynamic power factor correction. The converter system has at least one converter which has power semiconductors which can be switched on and/or off. It is possible to influence the current flow through the power semiconductors by adjusting the times at which the power semiconductors are switched on and off. It is also possible to influence the desired overall voltage or the desired overall current at the output of the converter by suitably controlling the times at which the individual power semiconductors of the converter are switched on and off.

Abstract: A linear voltage regulator includes a pass device for supplying current to a load, and an error amplifier for generating a control signal for controlling the pass device for regulating an output voltage at the load. The error amplifier is connected to a first power supply having a first voltage and a second power supply having a second voltage greater than the first voltage. The error amplifier preferably includes an output stage for providing a greater amount of current to the pass device from the first power supply than from the second power supply when the control signal is below a predetermined value, and for providing a greater amount of current to the pass device from the second power supply than the first power supply when the control signal is above the predetermined value. The predetermined value may be slightly above the typical drive or control voltage needed for a bipolar pass device.

Abstract: A switched-mode power supply includes a transformer having a primary winding, a secondary winding and an auxiliary winding. A switching device is included in series with the primary winding for alternately interrupting the flow of current through the primary winding. The switched-mode power supply further includes a controller circuit connected to the auxiliary winding for receiving information related to an output voltage across the secondary winding and for controlling the switching of the switching device so as to maintain the information at a desired level. The controller circuit including a sample-and-hold circuit which is controlled to sample the information related to the output voltage only when there is current flowing in the secondary winding.

Abstract: An monolithic programmable dc--dc converter controller integrated circuit with a high speed synchronous controller and a 4-bit programmable DAC to provide an operating voltage to an external device such as a microprocessor in response to a code programmed in the external device. The 4-bit programmable DAC outputs a signal which is combined with a precise reference voltage to provide voltages to the external device in increments of 100 millivolts.

Abstract: A method and apparatus for controlling the providing of conditioned AC power, with the conditioned AC power being capable of being provided on a continuous basis. Unconditioned AC voltage is received by transverters. The transverters convert the unconditioned AC voltage into a transverter AC output voltage. The transverter AC output voltage is monitored by current and voltage sensors. A transverter control signal is developed in response to changes in the current and voltage sensing in comparison with a reference signal. The transverter control signal then regulates conversion of the transverter AC output voltage into the desired conditioned AC output voltage. In multi-phase AC voltage systems conditioned AC voltages for each phase are provided.

Abstract: In a piezoelectric transformer driving circuit which comprises a boosting circuit (2) for boosting an input direct current voltage, a piezoelectric transformer (3), a current voltage converting circuit for converting a load alternating current which flows in the load (9), and a rectifier circuit (5), an input voltage detecting and comparing circuit (10) compares the input direct current voltage with a minimum voltage which is determined by a setting value of the load alternating current to produce a first voltage having a high level when the input direct current voltage is lower than the minimum voltage and to produce a second voltage having a low level when the input direct current voltage is higher than the minimum voltage. A reference voltage producing circuit (6a) produces one of first and second reference voltages in response to one of the first and second voltages.

Abstract: A power supply having a control system for permitting intelligent operation. The power supply: (i) is convenient, safe, and easy to program; (ii) is provided with a graceful shutdown in which output filter capacitor(s) are rapidly discharged while minimizing wasted energy; (iii) tracks and optimizes scheduled maintenance; (iv) permits two-way communication between the power supply and its controller; and/or (v) permits intelligent reconfiguration of a group of connected power supplies when one or more fails.

Abstract: A power supply system includes a power distribution circuit (21) and a power converter circuit (22), an input power control circuit (24), a power utilization circuit (26) and a utilization control circuit (28). The power distribution circuit includes some limitation in delivering power to the power converter circuit. The input power control circuit initiates and controls the start-up of the power conversion circuit. The power utilization circuit and the utilization control circuit include a first storage capacitor (96), a first load (98), and a second capacitor (112). A voltage comparator (104) monitors voltage across the second capacitor to determine when the second capacitor is fully charged. A gate (126) receives signals from the voltage comparator and status logic to cause a switch (102) closure when the second capacitor is fully charged. The closing of the switch connects a second load (100) in parallel with the first load.

Abstract: The invention relates to a power supply system having plural converters connected in parallel. The current of each of the plural converters is detected and each of the converters is controlled so as to match each of the converters to a maximum current value from among the detected current values. In the parallel converters, when one or more converter fails, having an output current of zero, the remaining converters are each partially charged equally to maintain the load current. Since a common bus is arranged between plural converters and plural loads, it is possible to carry out a redundant operation having a high reliability. Since a stable output can be obtained without being affected by the failed converter, a power supply system having the redundancy and the high reliability can be attained.

Abstract: A method and apparatus for controlling the providing of conditioned AC power, with the conditioned AC power being capable of being provided on a continuous basis. Unconditioned AC voltage is received by transverters. The transverters convert the unconditioned AC voltage into a transverter AC output voltage. The transverter AC output voltage is monitored by current and voltage sensors. A transverter control signal is developed in response to changes in the current and voltage sensing in comparison with a reference signal. The transverter control signal then regulates conversion of the transverter AC output voltage into the desired conditioned AC output voltage. In multi-phase AC voltage systems conditioned AC voltages for each phase are provided.

Abstract: A universal input dimming circuit for coupling an isolated external control signal into a variable output power supply, particularly those used for driving fluorescent lamps. Circuitry is incorporated which allows to discriminate between a DC control voltage or a relatively low-frequency pulsewidth-modulated signal using the same pair of input leads. By appropriate conditioning and waveshaping, the circuit produces a pulsewidth-modulated output which is then coupled across an isolation boundary and then demodulated to provide a command signal to the dimming ballast.

Abstract: A high-voltage stabilization circuit of a monitor can detect accurately a change of a high voltage of a secondary winding of a high-voltage transformer.

Abstract: A current control circuit for improved power application and control of thermoelectric devices to maintain the temperature of thermoelectric devices at a set point. The circuit includes at least one thermoelectric device, an inductor device, a current sensor and a switch device operatively connected in a series connection across a pair of terminals to allow current to flow therethrough when the switch device is activated to the "on" condition; a temperature sensor operatively positioned to monitor the temperature associated with the at least one thermoelectric device; a comparator device receives an input from the current sensor and provides an output to the switch device; a programmable control device receives an input from the temperature sensor and provides an output to the comparator device, the value of the output is determined by the difference between the sensed temperature of the at least one thermoelectric device and the desired set point temperature of the at least one thermoelectric device.

Abstract: A system and method for measuring the load current in a power supply driven by switched transformer or the like. Rectified rectangular waveform input voltage pulses are interrupted to exhibit a less than 100 percent duty cycle with an off state value approaching zero volts. A filtering inductor is situated in normal manner between the input voltage pulses and the load. Preferably, a capacitor is connected across the load. A freewheeling diode and sensing resistor are connected across the less than 100 percent duty cycle rectangular input voltage. The peak values of the current pulses through the sensing resistor have been determined to be related to the load current of the power supply. The voltage drop across the resistor is amplified, detected and used to regulate the magnitude of the limited duty cycle input voltage. The voltage drop across the resistor may be used to limit the power supply output current or to balance current in parallel configurations of multiple power supplies.

Abstract: A chopper control apparatus including a measurement device which measures the mean value of an output magnitude of the chopper, and a regulator which controls the supply of control square-waves for the chopper on the basis of measurement results supplied by the measurement device and a reference magnitude, so as to make the mean value equal to the reference magnitude. The measurement device includes a device which generates a sampling signal having pulses whose positions, relative to the control square-waves, are determined so that the pulses coincide with the output magnitude passing through its mean value. The measurement device further includes a sampling device which samples the output magnitude based on the sampling signal.

Abstract: An apparatus and method for generating a sensing signal from a generally periodic AC signal. The apparatus includes a first integrating circuit (125) for generating a first integrated signal by integrating the AC signal during a time period between positive transitions of the AC signal. The first integrating circuit (125) is reset by pulses from a pulse generator (100) at negative transitions of the AC signal. The apparatus further includes a second integrating circuit (135) for generating a second integrated signal by integrating the AC signal during the time period between positive transitions of the AC signal. The second integrating circuit (135) is reset by a further pulse generator at positive transitions of the AC signal. The sensing signal is generated by taking the difference in magnitude between the first and second integrated output signals.

Abstract: A switching power source apparatus for producing power signals. The apparatus includes a rectification circuit for rectifying received alternating voltage signals, a smoothing circuit for smoothing the rectified signals and a switching power supply circuit for producing the power signals. The apparatus may include a circuit for extracting low voltage signals from the switching power supply circuit and for superposing such low voltage signals on the smoothed rectified signals so as to reduce a ripple component present in the smoother rectified signals. The smoothing circuit and the switching power supply circuit may utilize a common switching device and/or a common frequency switching signal.

Abstract: A current detection method for a direct-current (DC) to three-phase alternating-current (AC) converter can utilize only a single DC sensor to detect and calculate the three-phase alternating currents. The method can detect a direct current value of one phase at each of six different gate states of three pairs of transistors in the DC to three-phase AC converter by means of the DC sensor. In the two-level pulsewidth modulation control, the control signal includes a plurality of carrier periods each being subdivided into three intervals. The three pairs of transistors are switched to the zero state in one interval of each carrier period, and to two different gate states respectively in the two other intervals. The method can detect two current values of different phases respectively in the two other intervals of each carrier period, and then calculate the current value of the other phase in accordance with the principle that the sum of the three-phase currents is always equal to zero.

Abstract: An embodiment of the present invention is a switching power supply comprising a transformer with a primary and two secondaries, a switching transistor in series with the primary, a rectifier and filter on one secondary to provide regulated output power, a feedback control circuit that monitors the secondary and adjusts the duty cycle of an on-off control signal to the switching transistor to maintain a constant output at the terminals, and a monitor that detects when the power level flowing through the switching regulator has dropped to a predetermined minimum and then linearly turns on a load to the transformer. Transistor is typically a power MOSFET. The monitor tracks a summing junction current before any slope compensation is added. Load is a shunt regulator that is activated when the summing junction current falls below 12% of full scale. Alternatively, the predetermined value of 12% is adjustable.

Abstract: A capacitor-charging series resonant mode, high voltage power supply (SRMPS) (10) includes a switching network (30) that alternately applies a positive and negative voltage to a series resonant circuit, comprising a resonant capacitor and inductor. The inductor may include the primary winding (14) of a power transformer (12). The switching action occurs at a fixed frequency above the audible range. This frequency is approximately the resonant frequency of the series resonant circuit. The switching action causes sine wave quantums of current of alternating phase to flow through the primary winding. Secondary windings (16) of the transformer are coupled through a suitable rectifying network (18) to charge a load capacitor C.sub.L to a high voltage. During a first mode of operation the load capacitor is charged at a maximum rate. During a second mode, the load capacitor is charged only as needed to maintain a desired charge thereon.

Abstract: A switching power supply for controlling an output voltage to a constant value with respect to fluctuations in input or in load, wherein are provided a DC power supply; two dividing capacitors connected in series to both ends of the DC power supply; two semiconductor switches connected in series to both ends of the DC power supply; a transformer having a primary winding, one end of which is connected to a connecting point of the two dividing capacitors; and a T type circuit comprising two inductors connected in series between the connecting point of the two semiconductor switches and the other end of the primary winding; and a capacitor connected between the connecting point of the two inductors and the other end of the primary winding. The control characteristics of the switching power supply are improved by reducing the dependency of the output voltage on fluctuations in the load.

Abstract: A voltage stability discriminating system for a power system is disclosed for calculating a multiple load flow solution relating to a voltage stability discrimination for a power system in which the voltage stability can be discriminated fast and accurately due to the fact that the voltage stability discrimination system of the power system is constructed such that the multiple load flow solution is estimated in advance during a calculation process of the load flow calculating means.

Abstract: A regulation technique for regulating at least one auxiliary output of a power supply having a regulated main output. When the auxiliary output reaches a first or a second predetermined value, the feedback circuit of the power supply is adjusted such that the auxiliary output is substantially maintained within the first and second predetermined values.

Abstract: A brushless DC motor useful as a driving source of a refrigerant compressor of a refrigerating apparatus or a fan. A position detecting means generates a control signal by detecting the terminal voltage on input-output terminals current to three-phase rotor drive coils. Filters convert the detected terminal voltages to smoothed signals. A mixing means generates three kinds of mixed signal from the smoothed signal and comparing means generates the control signal for switching a current path to the three-phase coils by a signal made by comparing the mixed signal with the smoothed signal. The current path to the coils is switched by a switching-driving part in turn on the basis of the control signal of the position detecting means.The present invention provides a brushless DC motor wherein current flowing to the drive coils can be switched without special position detecting elements.

Abstract: This invention relates to a bi-polar power supply regulator. A regulator is shown and described which prevents undesirable and potentially dangerous power supply build-up in a power amplifier of the standard totem pole configuration. The regulator also enables one to construct a multi-amplifier system in a cost effective manner since the regulator controls the build-up in the bi-polar power supply which is used to drive several power amplifiers in the totem pole configuration.

Abstract: An overvoltage protection circuit limits the output voltage of a DC to DC converter to a maximum desired output voltage. An output voltage sensing circuit includes a semiconductor device such as a sidac having a normal resistive region of operation as well as a negative resistance region of operation which begins at a breakover voltage and extends into a foldback region. One terminal of the sidac is coupled to sense the converter output voltage while the second terminal opposite end of the sidac is coupled to a biasing device in the form of a resistor which generates an overvoltage signal when the sidac conducts current. The overvoltage signal from the biasing resistor is coupled to a converter switching transistor disabling circuit which reduces the converter output voltage to a level below the maximum desired output voltage in response to the overvoltage signal.

Abstract: An apparatus and method relative to the operating of a control turn-off semiconductor device provide for determining the actual control electrode to cathode voltage upon the application of a turn-off control signal by adjusting the apparent value of that voltage by a value representing the voltage drop due to inductance in lead lines. The thusly adjusted value is employed to develop an output signal which indicates that the device has been turned off. In a further embodiment, the output signal may also be employed to reduce the value of the control signal from a first, relatively high value to a second, relatively low value.

Abstract: A DC/AC converter (30 to 72) for feeding a low-pressure mercury vapor discharge tube (15) comprises two series-connected main transistors (11 and 20) which, in the operating condition, are alternately conducting. The conduction times of the two transistors (11 and 20) are always kept equal to each other by means of an auxiliary circuit (70 to 72, 32a, 32b, 32c) which influences the operation of a timing circuit (32, 33). This prevents the occurrence cataphoresis in the lamp.

Abstract: A DC/AC converter provided with two transistors (11 and 20) alternately conductive to supply current to an inductively stabilized discharge lamp (16, 15) to be connected to the converter. The lamp is connected in series with a primary winding (12) of a current transformer. A secondary winding (30, 31) of the transformer is connected to a timing circuit (32 to 35; 32' to 35') of a control device of the transistors. The timing circuit is provided with voltage-dependent elements, i.e. Zener diodes (35, 35'). The combination of the current transformer and the Zener diodes causes the frequency of the converter, during starting of the lamp, to be larger than during the operating condition of the lamp. This insures that the lamp electrodes are properly heated before the lamp ignites.

Abstract: Circuits for providing a variable-amplitude D.C. analog control signal to a load, responsive to the time duration of a periodic, variable-pulse-width input signal, while providing isolation between the input signal circuit and the load circuit. Embodiments utilizing either a fly-back transformer or an optoelectronics isolator, are disclosed.

Abstract: Programmable power supplies as used in automatic testing systems (ATS) require three commands from a computer; namely, polarity, gain and analog magnitude. Whether received from a general purpose bus such as the IEEE 488 or other means the commands are in parallel format and must be serialized. The three commands must be recognized and decoded and applied to the appropriate power supplies. The present invention in addition to furnishing the above responses, provides optical isolation to eliminate possible ground loops and other voltage difference problems. One significant simplification comprises the use of sample and hold amplifiers in place of the more conventional latches so that new commands can be accumulated without affecting the response to a prior command.

Abstract: Induction heating apparatus using gate-controlled switching devices includes a zero crossing point detector for detecting the occurrence of each zero crossing point of high frequency energization current, and a timing circuit which provides timing action in response to the detected zero crossing point. The timing action is controlled by a power control circuit which detects the level of energy delivered to a load within a range from the inherent turn-off time of the gate-controlled switching devices to a desired value.

Abstract: In a paralleled inverter system, a positive feedback current derived from the total current from all of the modules of the inverter system is applied to the base drive of each of the power transistors of all modules, thereby to provide all modules protection against open or short circuit faults occuring in any of the modules, and force more equal current sharing among the modules during turn-on of the power transistors.

Abstract: Apparatus for use in balancing an asymmetrical load which is supplied from a three-phase network. The apparatus is provided with a self commutating converter for generating a three-phase output current system on its a-c side which is fed with phases reversed to the network. The d-c side of the converter, in turn, is fed from a d-c source with a d-c current corresponding to the maximum asymmetry power to be balanced.

Abstract: Induction heating apparatus using gate-controlled switching devices includes a zero crossing point detector for detecting the occurrence of each zero crossing point of high frequency energization current, and a timing circuit which provides timing action in response to the detected zero crossing point. The timing action is controlled by a power control circuit which detects the level of energy delivered to a load within a range from the inherent turn-off time of the gate-controlled switching devices to a desired value.

Abstract: In a chopper control device in which a magnetic phase shifter is used for providing chopper turn-on and turn-off signals, an external magnetic field is applied to the core of the magnetic phase shifter so as to carry out the notching control of a motor by regulating the residual phase angle of the output of the magnetic phase shifter.