Abstract: A three-state switch designed to be inserted in an ac supply circuit and associated with a state selection circuit. In a first state, the switch is open and does not allow current to flow. In a second state, the switch allows current of a first polarity to flow. In a third state, the switch allows a current of a second polarity to flow. The switch includes a cathode gate thyristor and an anode gate thyristor connected head-to-tail, the gate of the cathode gate thyristor forming a control terminal and being connected through a resistor to the gate of the anode gate thyristor.

Abstract: A phase controlled weld controller system provides a stable timebase phase reference which has improved transient response in the presence of spurious noise generated by other external equipment coupled to the same voltage source. The system estimates a phase error between an internal phase reference generator and the voltage source. The system also estimates the phase distortion generated by the weld control when operating with an inductive impedance load when significant line impedance is present. The weld controller provides compensation for the phase distortion in the timebase phase reference using the estimated line impedance to realize a phase reference which more accurately tracks the voltage source.

Abstract: A resonant convertor control system regulates a resonant AC current based on the amount of input power consumed by the system. The switching frequency and resonant AC current are limited by a phase difference assurance circuit that compares the phase of a drive signal with the phase of the resonant AC current. By detecting the phase of the resonant current instead of the resonant voltage, it eliminates the need for the costly components required to detect the resonant voltage. The system includes a main power supply for supplying a DC power signal and an inverter that converts the DC power signal to a resonating AC current signal responsive to a drive signal from a drive stage. An input current controller receives a first sense signal that indicates the power consumed by the main power supply and generates a first control signal that regulates the power consumed by the load.

Abstract: A local signal of a predetermined frequency is supplied to an input terminal of a local signal input section. The local signal is applied to a control input terminal of a variable current supply and, in accordance with the local signal, a current is output from a variable current supply and sent to a phase-shifting section. The phase-shifting section includes two resonance circuits each comprised of a capacitor and inductor. The two resonance circuits are connected in parallel with a linear element constituting the local signal input section to output first and second output signals of the same frequency as that of the local signal and whose phases are shifted by a predetermined amount. The respective output signals of the phase-shifting section are output to a next stage through a signal output section comprised of two sets each of a current supply and transistor.

Abstract: A phase controlled 50 percent duty cycle variable output bridge power converter in which the 50% duty cycle is maintained constant while power output is controlled by changing the phase relationships between two 50 percent duty cycle square waves. When the 50 percent duty cycle square waves are 180 degrees out of phase, the output power is maximum, whereas when the waves are in phase, the output power is essentially zero. The circuits are conditioned to operate in a current mode, snubbing circuits are provided to improve load line characteristics and power consumption of the switching elements, and both soft start-up and controlled shut-down circuits are included to further enhance circuit performance.

Abstract: A local signal of preset frequency is supplied to an input terminal of a signal input section. The local signal is supplied to a control input terminal of a variable current source, a current corresponding to the local signal is output from the variable current source, and the current is supplied to a phase shifting section. The phase shifting section includes an integrator constructed by a capacitor and a resistor connected in series and a differentiator constructed by a resistor and a capacitor connected in parallel. As parallely connecting the phase shifting circuit with a linear element of which the signal input section consists, the phase shifting section outputs first and second output signals which has the same frequency as the local signal and whose phases are different from each other by 90.degree.. The output signals of the phase shifting section are output to the next stage via an orthogonal signal output section constructed by current source and transistors.

Abstract: A phase control circuit for operating a phase shift in accordance with a control voltage comprises four differential circuits, two of which form a multiplier circuit for providing a basic function for a phase shift operation of the phase control circuit, and the rest of which cancel variations in amplitude generated during the phase shift operation. The amplitude compensation is accomplished by a construction in which a ratio of an emitter area of a first bipolar transistor in each of the differential circuits to an emitter area of the second bipolar transistor in each of the differential circuits is set at a value between 2 and 3. Alternatively, the amplitude compensation is provided by a level shift circuit providing an offset voltage in the control voltage supplied to two of the differential circuits.

Abstract: A dynamic phase angle regulator for enhancing the transient stability of a three phase AC power system includes a controller, a switching assembly of thyristor switches, and a single transformer coupled to a power line. The transformer includes a balanced three phase configuration of exciting windings coupled to nodes at each phase of a three phase transmission system. Each phase of the transformer further includes a pair of regulating windings electrically coupled to the node and magnetically coupled to a corresponding exciting winding. Each exciting winding induces a voltage on the corresponding pair of regulating windings. To provide a selected phase shift, the controller actuates the switching assembly in response to a transient event to add a voltage induced on the regulating windings to the line voltage. A method is also provided for regulating the phase angle in a polyphase power transmission system.

Abstract: The present invention discloses a phase shifting circuit for generating several output signals wherein each of the output signals maintaining a constant phase difference. The phase shifting circuit includes a first input port for receiving an input signal with a reference input phase. The phase shifting circuit further includes a second input port for receiving the input signal with a 180.degree. from the reference input phase. The phase shifting circuit has a first branch connected between the first and second input ports, the first branch including a first resistor-capacitor (RC) segment connected in series via a first mid-point to a second resistor-capacitor (RC) segment wherein the second RC segment is configured, with reference to the first mid-point, in complete mirror symmetry relative to the first RC segment. The phase shifting circuit further includes a second branch connected between the first and second input ports in parallel to the first branch.

Abstract: The invention pertains to electrical power control more particularly to a class of circuitry known as thyristor phase control. The novel circuit can be used to control heating devices, electrical motors and generators and many other types of equipment that require a precise control of the output of a thyristor.

Abstract: A fully automatic phase controller for non-coil armature type generator includes a starting control circuit and an automatic voltage control circuit, to fully automatically control the phase according to the range of the amplitude or the forward and backward movement of a pulse train, by means of magnetic saturation using a TRIAC and a voltage stabilizer. According to the present invention, the controller is very compact and inexpensive to manufacture, which helps to provide a stable voltage while the phase is fully automatically controlled.

Abstract: A control device for an active filter according to the present invention comprises a ROM circuit for producing output signals sin .theta. and cos .theta. from a phase signal generated from a PLL circuit, a first multiplier for multiplying a load current detection signal by the output signals sin .theta. and cos .theta., a sample-holding circuit for integrating the output signal of the first multiplier and holding the integrated value to produce peak values of valid current component and invalid current component for constituting the basic wave component of the load current, a second multiplier for multiplying the peak values by the output signals sin .theta. and cos .theta., and a PWM control circuit for PWM-controlling the input current of the active filter with a harmonic current signal obtained as the difference between a basic wave current signal of the load current during a period of next one period of the single-phase a.c.

Abstract: A circuit arrangement for shifting the phase of a signal, in which the signal is applied to two parallel branches where one branch contains a phase-shifting network for purposes of applying a constant phase shift to the signal. A variable amplifier connected in one of the two branches controls the amplitude of the signal and inverts the polarity of the signal. This variable amplifier can be connected in series with the phase-shifting network, or the ampifier can be connected in the branch that is in parallel with the branch containing the phase-shifting network.

Abstract: A variable phase shifting circuit comprising a phase splitter for distributing an input signal supplied thereto into first and second output signals which are outputted therefrom and 90 degrees out of phase each other, a first double balanced differential amplifier to which the first output signal from said phase splitter is delivered as a first input signal, a second double balanced differential amplifier to which the second output signal from said phase splitter is delivered as a second input signal, a summer for summing the respective first and second output signals from said first and second double balanced differential amplifiers to output the summed result, a converter for converting a control input supplied thereto to a differential current, first logarithmic conversion means for converting said differential current of said converter to a first logarithmic voltage, circular function conversion means for converting said differential current of said converter to a circular function current, and second lo

Abstract: There is disclosed a clock circuit for a PBX system that uses phase locked loop technology to perform synchronization between two input signals. The system can switch between different reference sources without introducing error and without requiring the entire circuit to become realigned with the phase of the newly selected reference signal. This is accomplished with a phase build-out circuit that uses a phase locked loop divider to change the phase of the internal control signal to match the phase of the newly selected reference thereby eliminating timing changes on the system clock bus. The system can also be used to change between redundant clock circuits.

Abstract: An automatically variable all-pass circuit includes a variable impedance circuit for changing the shape of the phase characteristic of the output signal of the all-pass circuit as a function of the amplitude of the output signal of the circuit.

Abstract: Phase shifters are used in meshed, multi-phase power supply systems for improving their transmission stability and for load-flow regulating purposes. In order to be able to use a less costly exciter transformer of lower rating or the tertiary or compensation winding of a system coupling transformer for generating intermediate-circuit voltages as a function of system input voltages, a resonant circuit is provided between the exciter transformer and an auxiliary transformer. In this resonant circuit consisting of series-connected capacitors and inductive resistances which are connected to taps between these capacitors and can be switched in and out by means of alternating-current switches, tap voltages are generated which are supplied to the primary windings of the auxiliary transformer. At the secondary windings, connected in series with phase conductors of the auxiliary transformer, auxiliary voltages occur which are superimposed on the system input voltages and effect the desired phase shifts.

Abstract: A phase inverter generates two signals 180.degree. out-of-phase at microwave frequencies in response to an input microwave signal incorporating a semiconductor substrate such as gallium arsenide, a transistor having a drain, source and gate electrode, an ion-implanted resistor coupled between the drain electrode and a voltage source, a second ion-implanted resistor coupled between the source electrode and ground potential, a compensation network such as a capacitor coupled between the source electrode and ground potential, and a biasing network for establishing a bias voltage on the gate electrode. The phase inverter which may be monolithic overcomes the problem of the size of quarter wavelength slot lines to generate signals with 180.degree. phase relationship.

Abstract: An inexpensive power supply for an electconic control system or the like which is capable of converting a wide range of applied AC voltages into a regulated output voltage. A thyristor is coupled in series with an input terminal and a threshold device, such as a Zener diode, placed across the input terminals and paralleled by an RC circuit coupled to the thyrisor gate. Another capacitor is coupled to the thyristor cathode. A ramp-like voltage impressed on the thyristor gate effects triggering at a phase angle which varies in accordance with output voltage. The electronic control system outputs a uniform train of pulses which serve to disable a circuit interrupter. Termination or disruption of the pulse train causes the interrupter to open the protected circuit.

Abstract: The control circuit comprises a solid state controlled switch coupled to a terminal of the mains and a terminal of the load the supply voltage whereof has to be controlled, and a non controlled solid state switch operatively coupled to the solid state controlled switch for setting, in cooperation with resistive and capacitive elements, also supplied by the mains, the conduction time of the controlled switch in such a way as to adjust at predetermined maximum and minimum levels the load supply voltage.

Abstract: It is known that every single or multi-phase power consumer such as a motor is optimally designed only for a certain power take up. Other power take ups deviating from this value result in a decreased ratio between power output and current intake. The circuit arrangement described in this application facilitates a fully automatic regulation and thus immediate adjustment of the respective power consumption to the respective power demand so that a motor or similar power consumers can be operated under energetically optimum conditions even under partial load. As a function hereof an advantageous phase detection facilitates generation of a regulated voltage with the current intake being reduced with increasing phase shift resulting in an increase of the output factor. For this purpose a Triac in series with the power consumer in the network is triggered in a certain manner in multiplex operation and a circuit differentiation is made among several phase controls.

Abstract: Reactance means serially connected in a power line is shunted by selectively bidirectional conduction means which is triggered in response to half-cycle time periods of current waves exceeding a desired half-cycle time period and also in response to an over voltage across the reactance means.

Abstract: A transformer which is suitable for connecting with a compound network and renders possible shifting the phase angle of the secondary side-output voltage in relation to the primary side-input voltage. The secondary windings are divided into winding stages and there are provided lines and switches, by means of which these winding stages can be selectively connected in series. Since the phase angle of the voltage in each winding stage coincides with the angle of the corresponding winding, it is possible to vectorially add in this manner partial voltages with different phase angles, so that at the output terminal of one winding there appears a composite voltage whose phase angle is aligned in the same direction as said one winding or, in relation to such direction, is shifted through a predetermined angle value in clockwise direction or in counterclockwise direction.

Abstract: In a power supply circuit for an electrical apparatus, comprising a power transformer having its secondary winding connected to a smoothing capacitor via a rectifying circuit and having its primary winding adapted to be applied with an ac voltage, a switching means is provided for applying the ac voltage to the primary winding only for a selected period of time in a half cycle of this ac voltage and for terminating the application of this ac voltage before an arrival of a zero crossing point of the ac voltage, whereby allowing a voltage of a time length corresponding to a current flowing through the secondary winding to be applied to the primary winding of the transformer, to thereby inhibit a flow of unnecessary exciting current to the primary side. This power supply circuit also contributes to stabilization of the dc output voltage of the power supply circuit.

Abstract: Controllable phase shifters containing reactances and valve switching devices are used for compensation and stabilizing purposes in alternating current-energy transmission systems. There is desired a phase shift which can be continuously controlled within variable limits and with comparatively low expenditure in circuit components. There is provided at least one shunt circuit branch between primary terminals having mutual phase shifted voltages, and a tap provided as a secondary terminal supplies a secondary voltage or potential having a phase between that of the primary terminals. At both sides of the secondary terminal there are arranged in the shunt circuit branch preferably complementary reactive impedances. At least one valve switching device, controllable with respect to its gating behavior, is arranged in series or parallel to one such impedance and renders possible changing the magnitude of the impedance which is effective for the fundamental oscillation, and thus, a change of the control phase angle.

Abstract: Variable phase shift apparatus employing two transistors having their bases connected together and their collectors connected together. The input terminal is coupled to the emitter of the first transistor. A phase control arrangement of a capacitance and a variable resistance in series is connected between the input terminal and ground. The juncture of the capacitance and the variable resistance is connected to the bases of both transistors. A phase control signal is present at this juncture. The collector current in the first transistor is in phase with the difference between the input signal and the phase control signal. The collector current in the second transistor is 180.degree. out of phase with the phase control signal. The two collector currents are combined by flowing through a common load resistance to produce an output signal which is the resultant of the collector currents in the two transistors.