Abstract: A switching regulated push pull converter which includes voltage and current feedback loops to provide a highly regulated output voltage throughout a 100 percent load range. This circuit also provides a semi-regulated auxiliary output voltage which can be loaded beyond 100 percent of its load range with no minimum load requirement on the highly regulated output voltage. A direct current drive circuit for the push-pull power switches provides a transformerless proportional drive and means are provided to compensate for transformer asymmetry.

Abstract: A power control circuit has a thyristor bridge interposed between a.c. buses connected to an a.c. power supply and a load. The firing circuit for the thyristors of the bridge includes a light actuated controlled rectifier for generating firing pulses. Two series connected resistor-capacitor pairs are connected in series across the a.c. buses. Taps intermediate the resistors and capacitors provide an energizing anode voltage to the controlled rectifier reduced with respect to the a.c. voltage in the buses. The voltage reducing and capacitive properties of the pairs render operation of the controlled rectifier immune to transient voltage spikes in the a.c. buses.

Abstract: A constant current circuit including a silicon controlled rectifier connected to transmit current flow from an ac supply to a load. A sensor circuit provides a load signal having a level dependent upon the current flow through the load and a reference circuit provides a reference signal having a predetermined given level. Receiving the load and reference signals is a comparator with an output connected to an SCR firing control network that furnishes firing signals to a gate of the silicon controlled rectifier. The output from the comparator varies the firing signal produced by a phase shift network in response to a reference signal level greater than the level of the load signal and retards the phase of the firing signal in response to a load signal level greater than the given reference level.

Abstract: In a control apparatus for connecting three-phase current systems having respectively different frequencies to a high-voltage D.C.

Abstract: A regulation circuit for providing timing gate signals to the dc power section of a power supply, the regulation circuit utilizing phase angle conduction of a programmable unijunction transistor. The conduction angle is determined by the occurrence of the cycles of the ac source voltage unless earlier conduction is determined by the sensed dc voltage. Early conduction occurs when the control voltage to the PUT is allowed to build up beyond a predetermined level when the sensed dc voltage is low. When the sensed dc voltage is high, an electronic switch closes to discharge a storage element to prevent control voltage build up and, hence, early conduction. Ac source voltage failure also causes closing of the electronic switch to prevent undue regulation of the power section output at such times and to permit storage capacitors therein to maintain a dc output until source voltage is reestablished.

Abstract: The proposed digital control device controls a d.c. thyristor-pulse converter and comprises a decoder connected to a clock pulse counter and a reversible counter. The device further includes a control unit, a matching unit containing four AND gates and a sign flip-flop, and a switching unit having six AND gates and two flip-flops. A first AND gate of the switching unit is connected to a control electrode of a first thyristor, a second AND gate of the switching unit is connected to a control electrode of a second thyristor, a third AND gate is connected to a control electrode of a third thyristor, a fourth AND gate is connected to control electrode of a fourth thyristor, a fifth AND gate is connected to the control electrodes of the first and third thyristors, and a sixth AND gate is connected to the control electrodes of the second and fourth thyristors. The clock pulse counter and the AND gates are connected to the flip-flops of the switching unit.

Abstract: A circuit for sensing the current applied to a load in power supplies, inverters, and other power conversion equipment and similar systems wherein the voltage between the center tap of the transformer secondary winding and the junction of two resistors connected across the secondary winding in series is sensed. The control circuit for the electronic system adjusts the overall system operation to obtain the desired volt-ampere output in response to this voltage level.

Abstract: Apparatus for providing firing signals to a phase controlled rectifier circuit at a time at which valves in the rectifier circuit are forward biased without the need for providing continuous firing signals. The apparatus monitors the voltage applied across the rectifier valves and provides a signal when a valve is forward biased. This signal is applid to a gating circuit which determines whether a normal phase control firing command was initiated prior to the time the valve became forward biased. If such a command was initiated, the gating circuit passes the signal to a valve firing circuit which provides firing signals to the rectifier circuit. If the firing command was not previously initiated, the signal is inhibited and firing signals are subsequently applied to the rectifier circuit upon receipt of a firing command.

Abstract: In an AC-DC converter for converting an AC power by a six-phase, half-wave or three-phase, full-wave back-to-back or anti-parallel connection thyristor bridge to a DC power for input to a load, while the current to the load is small, the converter is actuated as a converter of a three-phase, half-wave back-to-back connection bridge, thereby to enable an alternate supply of negative and positive currents to the load. Letting the output by the AC-DC converting operation of the three-phase, half-wave back-to-back connection bridge and the output by the other converting operation be identified as main and auxiliary outputs, respectively, as the load current increases, the auxiliary output is also supplied to the load.

Abstract: A rectifier and preregulator circuit using a first silicon controlled rectifier (SCR) to rectify AC voltage and apply the rectified voltage across a capacitor which is used as a storage device. The circuit also includes a transistor, zener diode and a second (SCR) in a switching arrangement for turning on the first SCR and for turning off the transistor and zener diode when a minimum voltage is reached so as to minimize dissipation of electrical power in the circuit. A second zener diode and a third SCR are used in a switching arrangement to control the maximum rectified voltage from the circuit.

Abstract: A high-voltage thyristor converter having a plurality of series-connected thyristor units and a gate control system. Each of the series-connected thyristor units has a plurality of series-connected thyristors and a gate-drive power supply circuit (hereinafter referred to as a gate power supply) connected between both extreme ends of the series-connected thyristors for supplying gate-drive power to the thyristors. The gate control system detects whether or not an output voltage of the gate power supply of at least one of the series-connected thyristor units is at least equal to or higher than a predetermined value and transmits a gate signal simultaneously to all of the thyristors when the output voltage is higher than the predetermined value, so that a protective action for preventing breakdown of the thyristors can be performed upon an instantaneous power failure or the like trouble.

Abstract: An electronically stabilized feeder device for supplying regulated DC current to a load includes circuitry for adjusting the load voltage to a selected value, circuitry for adjusting the load current to a selected value, and circuitry responsive to load current to limit load voltage and thereby limit the power supplied to the load to the selected value and to reduce load voltage to its lowest value regardless of selected values in the event of a short circuit.