Showing papers on "Precision rectifier published in 1973"

High voltage generator for a television receiver

Abstract: A high voltage generator comprising a high voltage generating transformer having a primary winding and first and second secondary windings, a first rectifier having one end connected to one end of the first secondary winding, a capacitor connected to the other end of the first rectifier and adapted to be charged with the voltage appearing at the other end of the first rectifier, a second rectifier connected between the connection point between said first rectifier and said capacitor and one end of the second secondary winding, and a third rectifier for high voltage rectification connected to the other end of the second secondary winding. With this construction variation of the output high voltage with change in load current can be reduced.

Constant-voltage power supply

Abstract: In a power supply circuit useful for a horizontal deflection circuit in a television receiver, there is provided a voltage-controlled semiconductor element, for example, such as silicon controlled rectifier, in order to stabilize effectively the output power voltage. The silicon controlled rectifier is switched between its OFF and ON states in response to two kinds of pulses: flyback pulses occurring within the television receiver and newly produced control pulses having relative phases with respect to the phase of the flyback pulses which relative phases differ depending upon variations in the input power voltage. Current flow through the silicon controlled rectifier charges a capacitor connected thereto which in turn provides the stabilized output voltage to the horizontal deflection circuit.

Silicon controlled rectifier motor speed controller

Abstract: An electric motor, for driving an automotive vehicle, has its speed and torque controlled by variable impedance means connected to control the armature current in the motor The impedance means comprises a plurality of series-connected resistors and silicon controlled rectifiers, connected in a parallel array, with the resistors having different values respectively; and different ones of the rectifiers are rendered conductive to place different values of resistance in series with the motor armature circuit Commutating capacitors interconnect the anodes of the rectifiers to turn off each rectifier when a next successive rectifier in the array is rendered conductive The last rectifier in the array has no significant resistance in series therewith; and this rectifier is associated with a further capacitor which is in turn associated with two further silicon controlled rectifiers, one of which is rendered selectively conductive to charge the capacitor at a proper stage of the operation, and the other of which is subsequently rendered conductive to discharge the capacitor when it is desired to turn off the last rectifier in the array

Thyristor rectifier having a device for self-ignition or recovery protection

Abstract: A thyristor rectifier for high voltage includes a number of series-connected thyristors with a control device for each thyristor and a control circuit for the whole rectifier connected to the control devices. There is a control pulse emitter in each control device which emits an indicating pulse when the voltage over the corresponding thyristor in the conducting direction amounts to a certain value. A protection device is provided which emits a signal for the whole rectifier through a control pulse transmitter if a voltage grows in the conducting direction of the rectifier at a time when only an insufficient number of thyristors have regained their blocking ability. This protection device includes a memory circuit and a counter to register the indicating pulses from the emitters of the control devices and an output circuit connected between the counter and the control pulse transmitter which emits a signal for ignition of the whole thyristor in dependence on a predetermined number of indicating pulses.

Gate turnoff thyristor with a pilot scr

Abstract: Disclosed is a thyristor comprising a primary semiconductor controlled rectifier and a pilot semiconductor controlled rectifier. Conduction in the primary controlled rectifier is initiated by conduction in the pilot rectifier, which in turn is initiated by receipt of a preselected signal on a gate terminal. An auxiliary current drain contact is coupled to the gate region of the primary controlled rectifier. When a predetermined current is withdrawn from the gate region of the primary controlled rectifier through the auxiliary current drain contact the device turns off as described below. The current drain apparatus can include, for example, a selective coupling system such as a diode coupled to the gate contact so that the gate contact can be employed to withdraw current from the primary controlled rectifier portion.

Ferroresonant transformer battery charger circuit

Abstract: A battery charger circuit comprises a ferroresonant transformer. A first rectifier circuit connected between the transformer and a battery provides a first rate of voltage. A second rectifier circuit connected in ''''piggy-back'''' with the first rectifier circuit between the transformer and the battery provides a second rate of voltage.

Frequency shift keyed detector

Abstract: A frequency shift keyed detector comprises a signel limiter, a bandpass filter, a rectifier and an output circuit activated by a signal from a clamp circuit in response to a signal produced by the rectifier. The level of an output signal from the output circuit is used to tune the bandpass filter to the frequency of the incoming information bearing signal.

Power rectifier having phase control angle of firing signals independent of supply frequency variation

Abstract: A sample of the supply voltage for a power rectifier with phase control is passed through a filter which shifts it through a substantially constant phase angle of approximately n times 90*, where n is an integer, and may change its amplitude over a wide range with variation in supply voltage frequency. The reference signal, which is compared to the phase-shifted sample voltage to derive the rectifier firing signals, is varied in proportion to the amplitude of the filter output voltage. Inasmuch as the phase shift is constant and the ratio of filter output voltage to reference signal is also constant, the firing angles of the rectifier firing pulses are independent of supply voltage frequency and amplitude variations.

Control circuit for a thyristor rectifier

Abstract: A thyristor rectifier for high voltages includes a number of seriesconnected thyristors each of which has a control device. A control circuit for the whole rectifier includes a control pulse transmitter and a signal emitter for each thyristor which emits an indicating signal when the voltage in the conducting direction of the relevant thyristor reaches a predetermined value. The control circuit includes an input circuit to which signals for ignition of the whole thyristor rectifier are connected. The signal emitters and input circuit are connected to an AND-gate. The different signal emitters are connected to the AND-gate by an OR-gate. The OR-gate is connected to the AND-gate by a flip-flop and the output side of the AND-gate is connected to the flip-flop in such a way that a signal from the OR-gate energizes the flip-flop while a signal from the AND-gate switches it off.

Voltage protection circuitry for direct current powered machinery

Abstract: A diode and a current limiting resistor are serially connected between a grounded electrical conductor and the frame portion of an electrically operable machine supplied with direct current power from a remote power source through trailing conductors connected to the machine load. The diode is operable to prevent the frame from being raised to the full-line voltage of the power source in the event the polarity of the conductors is reversed. The current limiting resistor limits the flow of current, caused by transient voltages appearing on the frame, to an intrinsically safe level. A capacitor and a plurality of resistors arranged in parallel circuit relation with the current limiting resistor monitor the existence of a fault voltage appearing thereacross. When the capacitor receives a charge of a predetermined magnitude, a diac serially connected to the capacitor conducts current therethrough to the gate terminal of a first silicon controlled rectifier. The first silicon controlled rectifier switched to a conductive state provides a direct path for the flow of current from the frame to the grounded conductor. A second silicon controlled rectifier, switched to a conductive state upon actuation of the first silicon controlled rectifier, deenergizes a relay to thereby terminate operation of the machine and signal the condition of fault voltage applied to the frame.

Switch in half-wave rectifier circuit

Abstract: An electronic oven is provided in which the interruption of an output is controlled by interrupting the current passing in a magnetron of a high voltage circuit.

High voltage circuit of color television receiver

Abstract: In a high voltage circuit of a color television receiver, constructed such that the voltage of the secondary winding of a fly-back transformer is converted into high DC voltages by an n-ple voltage rectifier, and that the output voltage Eb of the n-th stage of the rectifier circuit is applied to the phosphor screen of a post-deflection focusing type or after-focusing type Braun tube, while the output voltage Em of the m-th stage (m < n) is applied to the shadow mask thereof, a high voltage circuit wherein a voltage stabilizing element is incorporated between the output terminal of the n-th stage of the n-ple voltage rectifier circuit and ground, and current is kept steadily flowing through the element, whereby the ratio between the voltages Eb and Em, that is Eb/Em, is held substantially constant against load fluctuations in the n-ple voltage rectifier circuit.

Rectifier bridge silicon controlled rectifier trigger circuit

Abstract: Corresponding to each silicon controlled rectifier of a threephase bridge rectifier circuit is a center tapped and an untapped secondary winding pair of a three-phase transformer, a pilot silicon controlled rectifier, a capacitor and an output winding of a magnetic amplifier. Each center tapped secondary winding supplies gate-cathode current to the pilot silicon controlled rectifier which corresponds to the same bridge circuit silicon controlled rectifier through the corresponding output winding of the magnetic amplifier. Each untapped secondary winding supplies gate-cathode current to the corresponding bridge circuit silicon controlled rectifier through the anode-cathode electrodes of the corresponding pilot silicon controlled rectifier and charging current to the corresponding capacitor. Each capacitor is also connected across another one of the untapped secondary windings which places a charge thereon prior to the time the corresponding pilot silicon controlled rectifier is triggered conductive through the anode-cathode electrodes.

DV/DT circuit for use in D.C. link converters

Abstract: A circuit for controlling the rate of change (dv/dt) of forward blocking voltage reapplied across a silicon controlled rectifier to prevent the silicon controlled rectifier from conducting after the silicon controlled rectifier is turned off including an LC network connected to the silicon controlled rectifier.

AC to absolute value linear converter

Abstract: An AC to absolute value linear converter for converting an AC input signal into a rectified absolute value output signal. The AC input signal is rectified into positive and negative half-wave signals by a precision rectifier, the half-wave signals then being combined into a full wave rectified signal and driven into the load, the rectifier, combiner and driver being electrically isolated from each other. Differential amplifiers with appropriate feedback networks are resistively interconnected to provide all required functions and high-frequency capability, wherein DC and symmetry balancing networks are included to substantially eliminate DC offset in the output, and to provide a symmetrical output signal for low amplitude input signals, respectively.

Control circuit for a high voltage power supply utilizing a rectifier cascade

Abstract: A high voltage power supply unit employs a control circuit for controlling the output voltage provided by way of a rectifier cascade. A highly ohmic resistance and a potentiometer having a movable tap are serially connected between a tap of the rectifier cascade and ground. The movable tap is connected to a difference amplifier by way of an emitter follower circuit and the difference amplifier is connected to control a high voltage generator which feeds the rectifier cascade. A power stage, in the form of a Darlington circuit, is interposed between the difference amplifier and the high voltage generator to provide a sufficiently high load current supply for the high voltage generator.

Optical detector for detecting rectifier tube failures and rf electrical discharges

Abstract: An optical detector in a high voltage system senses the blue glow discharge characteristic of insipient failure in rectifier tubes and removes system power. In a preferred embodiment the rectifier tubes are part of a voltage multiplier in a charged particle accelerator and an RF transformer is part of the high voltage supply. Another optical detector is employed to remove power from the accelerator upon sensing blue light in an arc discharge at the RF transformer coil.

Tube filament power supply

Abstract: In a television receiver employing vacuum tubes, and which includes a full-wave bridge rectifier circuit for developing the required direct operating potential for the circuits, and for energizing the filaments, a standby circuit delivers one-half wave rectified voltage to the filaments of the vacuum tubes during standby operation by means of an additional diode in one leg of the bridge rectifier. A switch and a further diode disconnects the bridge rectifier from the power supply filter during standby operation thereby preventing the application of the operating potential to the circuits during the standby operating mode. The circuit delivers full-wave rectified voltage to the filaments during normal operation.

Tone detection and switching circuit

Abstract: There is disclosed a test tone detector including a tuned circuit tuned to the frequency of a test tone, a precision halfwave rectifier circuit including a first solid state operational amplifier coupled to the tuned circuit and an output circuit including a second solid state operational amplifier coupled to the output of the rectifier circuit and to the tuned circuit to produce a full wave rectified output signal with voltage gain upon detection of the test tone to actuate a switching arrangement.

Digital Computation of Harmonic Components in Multiphase Controlled Rectifier Circuits

Abstract: Digital computation of harmonic components of output voltage of multiphase controlled rectifier circuits is discussed. Harmonic components are calculated by using Fourier transforms. Computed results for a three-pulse controlled rectifier circuit with an R-L load are presented.

Controlled avalanche rectifier chains for accelerating voltage supplies

Abstract: The reverse current and power dissipated in controlled avalanche rectifier chains are calculated. Analysis indicates that a very large number of such rectifiers can be safely cascaded in series without using sharing components. This is advantageous over conventional silicon rectifier chains where bulky and oxpensive capacitors have to be added to avoid voltage mis-sharing effects. An example is given for the design of a rectifier chain suitable for the high voltage supply of particlo accelerators.