Abstract: A method of synchesizing a system which effectively forces finite value of an impedance to zero comprising a most inner positive voltage feedback loop and an inner negative voltage feedback loop and an outer negative voltage feedback loop, whereby a voltage difference between the most inner positive feedback loop and the inner negative feedback loop is fed back to compensate for the voltage drop across the impedance of interest in both steady state and transient and whereby no current through the impedance is sensed and no parameters of the impedance including parameters of the plant under the control are required to be known implying minimization of measurement noise and adaptive/self-tuning operation, respectively, in applications in which the method is used to synthesize load independent switch mode power converters and electric motor drive systems, incorporating any kind of motor, of infinite disturbance rejection ratio and zero order dynamics.

Abstract: A start-up circuit for a switching mode power supply is described. The circuit has an initial supply means for initiating pulses from a pulse generator. Latches are used once a stable output current is established to disengage the initial power supply. Thus, the pulse generator and the switching transistor are protected from power surges.

Abstract: A switching power source having a rectifier circuit and smoothing capacitor for obtaining a d.c. power from an a.c. input, an oscillator circuit constructed of a serial circuit of a primary winding of a power transformer and a switching element for intermittently turning on and off the d.c. power, the power transformer having another winding of the power transformer for detecting the oscillation state of the oscillator circuit, and a rush current preventing circuit constructed of a parallel circuit of a resistor and a thyristor for turning on the thyristor upon reception of a signal from another winding, the rush current preventing circuit being connected at the input side of the rectifier circuit or between the output side of the rectifier circuit and the smoothing capacitor, the switching power source comprising a detector circuit for generating a signal when the interception period of the a.c.

Abstract: A method and circuit configuration for closed-loop control of trigger signals of switching transistors in a resonant converter power supply circuit element having closed-loop control dependent on a zero crossing recognition, wherein a prematurely responding zero crossing detector is provided, includes comparing a period of time between the generation of a trigger signal and the switching of a power transistor with a time interval between a premature response of a zero crossing detector and an actual zero crossing. This is done in order to obtain a closed-loop control signal for controlling a deviation action threshold of the zero crossing detector.

Abstract: A stable reference voltage generator using a current mirror circuit comprising a primary branch and a secondary branch, is shown and described. A first bipolar transistor (Q1) has its collector connected in series with the primary branch of the current mirror, and a voltage divider bridge comprising at least two series-connected resistors (R1, R2), is connected in series between the secondary branch of the current mirror and the collector of a second bipolar transistor (Q2). The base of the second transistor (Q2) is connected to the common point of the series resistors, the base of the first transistor (Q1) is connected to the collector of the second transistor (Q2), and the output of the generator (V.sub.REF) is connected to the terminal of the bridge opposite that connected to the collector of the second transistor (Q2). The geometry of said transistors being such that the first transistor (Q1) is equivalent to "N" transistors identical to the second transistor (Q2) connected in parallel.

Abstract: A pulse-width modulated DC-DC power supply is illustrated with overvoltage protection which upon initial detection momentarily shuts down the pulse-width modulating portion of the control loop for a given cycle. If the overvoltage condition persists for more than a prescribed number of cycles or amount of time, the power supply is shut down permanently. The delay between momentary and permanent shut down being used to allow system operation to be maintained with minimal damage (voltage induced load stress) where large voltage transients may be temporarily introduced into the system.

Abstract: The invention relates to a voltage multiplying circuit having several stages, with each stage having a pumping capacitor and several MOS switching transistors. The switching transistors are so controlled by clock signals that the charge of a pumping capacitor of one stage is transferred to the pumping capacitor of the following stage. Operation of a circuit of this type with operating voltages substantially lower than 5 V entails considerable drawbacks. In accordance with the invention, therefore, each stage of a voltage multiplying circuit of this type is fitted with an additional transistor and an additional correction capacitor. As a result, the circuit in accordance with the invention is suppliable with an operating voltage of 2 V, for example. In another circuit arrangement, the transistors of the last two or three stages of the voltage multiplying circuit are of one conductivity type, while the transistors of the previous stages are of the opposite conductivity type.

Abstract: An electronic controller comprising two input terminals between which an AC line and an electrical load are connected in series. A processing unit generates a command signal to control the supply of electrical power to the electrical load which closes an electronic switch also connected between the two input terminals for connecting the AC line and the load in series in a closed loop. A power supply voltage of the controller is provided by a second power supply derived from the two input terminals, consequently from the AC line through the load when the switch is open. When the command signal is generated, an electronic circuit opens the switch which is normally closed by this command signal to maintain the power supply voltage of the controller according to an adequate standard of operation. To energize the controller, the opening of the switch is activated in a temporary and repetitive manner for a certain whole number of cycles of the sector.

Abstract: A power supply for an X-ray tube having a feedback loop for regulating the high-voltage output signal of the power supply and allowing operation from AC lines of different voltage characteristics. The single-phase components of the input AC line voltage pass through separate silicon controlled rectifiers before being applied to a step-up transformer. The high-voltage transformer output is monitored by a shielded resistor divider and processed to produce a low-voltage control signal for controlling the input rectifiers.

Abstract: A power converter unit includes a pair of switching DC/DC converter secti for positive and negative voltages which incorporate a MOSFET switching arrangement in which a pair of MOSFETs are forced to share the output load current equally, a current limiting arrangement which activates shutdown whenever the current threshold limit is exceeded, and an internal grounding arrangement which minimizes output of current spikes by isolating the switching spikes from the input and output. The current limiting arrangement includes a resistor for sensing the voltage between the input and output of the converter and a comparator for comparing the sensed voltage with a reference threshold voltage and being operable to shut down the converter when the sensed voltage exceeds the reference threshold voltage.

Abstract: A power supply system for a motor vehicle includes a battery of high voltage for a load system rated at 48V and a high-voltage generator for charging the battery. Loads rated at high voltage are supplied with electric power directly from the battery. A power MOS IC element connected in parallel with the battery is controlled in accordance with a predetermined duty factor for producing at an output terminal thereof an average low voltage of 24V or 12V, wherein low-voltage loads are supplied with the low output voltage.

Abstract: A differential, voltage-controlled current source, employing operational amplifiers as the active elements, provides an essentially symmetrical, differential, high impedance drive to a load, the drive being isolated from any circuit common or system ground. Because of the "floating" differential drive and the identical source impedances of the two outputs, errors from common mode voltages are eliminated.

Abstract: This invention relates to a PWM power converter for switching a plurality of bridge-connected semiconductor switching elements based on PWM signals. As the semiconductor switching elements, elements with a low ON voltage and small conduction loss, and elements with a small switching loss and capable of high-speed switching are combined to improve power conversion efficiency.

Abstract: A high voltage generator using a flyback transformer to generate high voltage pulses and including a control switching transistor inserted in a power supply circuit in a manner to be turned off during a trace interval. The amount of electric energy accumulated in a resonance circuit is intermittently controlled by the on-off action of such switching transistor, so that the level of the high pulse voltage outputted via the transformer can be maintained constant to consequently enhance the response characteristic in the voltage regulation while minimizing the number of required component elements.

Abstract: Power conversion apparatus for AC to DC to AC power conversion includes a rectifier bridge formed of rectifying devices (24,25) connected to an AC source (21) and providing a DC output to DC bus lines (27,28). A full bridge of active switching devices (30, 31, 34, 35) is connected across the DC bus lines to which a power source such as a battery (39) may also be connected. The load (36) and the AC power supply (21) share a common neutral line (33). The output of the bridge can provide AC output power to the load through a transformer (74). The power conversion apparatus allows full control of the currents on the load lines and AC input lines, even when the input and output are asynchronous. By providing an external DC power source such as a battery (39), uninterrupted power can be supplied to the load when the AC power source fails.

Abstract: A high voltage stabilizing circuit comprises a high voltage generating circuit (FBT, D1) for boosting a pulse voltage (Vcp) generated from a horizontal deflection circuit (Q1, D2, Ct", Ly, Cs) during a flyback period of a horizontal deflection pulse, a flyback period control circuit (Q2, C.sub.B, Rv, Ct') for performing switching operation only during the flyback period to control the flyback period, so that the high voltage (HV) is controlled, and a switching control resistor (Rv) for controlling the period of its switching operation.

Abstract: A DC dynamoelectric machine with interpoles between field poles operable in sparkles even under heavy operating conditions comprising a solid soft iron magnetic flux bypassing members, each disposed between respective field poles and interpoles at their ends near its armature with an air gap between the field pole for controlling interpole magnetic flux, the solid soft iron magnetic flux bypassing member suppresses sudden change of magnetic flux flowing therethough by permitting flow of eddy current therethrough and maintains the interpole magnetic flux at a desired amount even during a sudden change of load current.

Abstract: A positive temperature coefficient current source having reduced reference current requirements. The output transistors are each buffered by another transistor in a Darlington pair configuration. The reference current required for the circuit is reduced while maintaining a positive temperature coefficient for the current source.

Abstract: A parallel multi-inverter system including a plurality of inverters connected in parallel to each other through one or more parallel reactors, wherein output voltages of the inverters are controlled on the basis of the polarity of an output voltage command signal and a comparison result between a value obtained by converting the output voltage command signal into a positive one and a carrier signal to reduce harmonic components of the line-to-line voltages, and further two different switching modes to set the output voltage of the system zero are equally used to prevent a circulating current from flowing through the parallel reactors during each zero potential period of the output voltage of the system.

Abstract: A temperature-compensated voltage generating circuit suited for an output stage of a logical circuit is provided. The voltage generating circuit includes a bipolar transistor, a first resistor connected between the collector and the base of the bipolar transistor and a series circuit including a second resistor and a Schottky barrier diode and connected between the base and the emitter of the bipolar transistor. The temperature dependency of the base-emitter forward voltage of the bipolar transistor is offset by the temperature dependency of the forward voltage of the Schottky barrier diode by having the ratio of the resistances of the first and second resistors set based on a predetermined formula.