Showing papers on "Precision rectifier published in 1972"

Electric power supply system using back-up capacitor

Abstract: Herein disclosed is an improved d-c power supply system which comprises a d-c power source, a first rectifier serially connected to the power source, and series connection composed of a protective resistor and a back-up capacitor, the series connection being connected across the first rectifier and the power source, and the protective resistor being bypassed by a second rectifier so that a discharge current from the back-up capacitor flows through the second rectifier. The power supply system further comprises means for producing information signals representing condition of the back-up capacitor.

Method for controlling a rectifier circuit with controlled rectifiers and associated quenching devices

Abstract: In a method and corresponding circuitry for controlling a rectifier circuit having a controlled rectifier, the controlled rectifier is fired at an electrical angle alpha and is quenched at an electrical angle beta . A circuit arrangement is provided for establishing a quenching period during which quenching of the controlled rectifier occurs. This quenching period begins at an electrical angle after the A.C. supply current has reached its maximum value and ends prior to the electrical angle at which the A.C. supply voltage subsequently crosses through zero. The controlled rectifier is quenched at an angle beta lying within the quenching period and having a value which is adjustable in dependence on a momentary value of the A.C. supply current.

Three-phase inverter control circuit

Abstract: A three-stage shift register circuit, responsive to the output signals of a variable frequency oscillator, produces a repeating series of six equally spaced electrical timing signals A differentiating circuit corresponding to each electrical timing signal is responsive to the leading edge of each corresponding electrical timing signal to produce a corresponding gate signal pulse Each gate signal pulse is amplified by a corresponding amplifier, the output of which is connected across the primary winding of a pulse transformer having three secondary windings, a respective secondary winding of each pulse transformer is connected across the gate-cathode electrodes of each the extinguishing silicon controlled rectifier of a three-phase inverter circuit through which a three-phase motor may be energized from a direct current supply potential source which corresponds to the inverter silicon controlled rectifier to be extinguished, the inverter silicon controlled rectifier next to be triggered conductive and the inverter silicon controlled rectifier last triggered conductive

Automatic chroma gain control system

Abstract: Cascaded first and second gain-controlled amplifiers are used in the chrominance channel of a color television receiver. The gain of the first amplifier is controlled by an ACC loop employing a noise-immune detector to detect color burst information. The gain of the second amplifier is controlled by the output of a peak detector which detects picture-interval information at the output of the second amplifier. An ACC system with improved performance during the reception of noisy signals results.

Rotation sensing pulse control generator for triggered ignition systems and the like

Abstract: A capacitor discharge ignition system includes a main controlled rectifier in series with a capacitor to discharge the capacitor into the spark plug through a suitable pulse transformer. A pilot controlled rectifier connects a firing winding to the gate of the main rectifier. A second control winding, connected to the gate of the pilot rectifier, is mounted in spaced relation to the firing winding. A common magnet is rotated in synchronism with the engine. Only one direction of rotation generates the pulses in proper sequence to the two controlled rectifiers.

Condition responsive circuit with capacitive differential voltage

Abstract: A condition responsive circuit, disclosed as including a temperature responsive element, is adapted to be connected to by a pair of terminals by an alternating current load and to a source of alternating current voltage. The condition responsive circuit operates through a differential amplifier to control a solid state switch, shown as a silicon controlled rectifier. This solid state switch in turn operates further solid state switching to control the load. A capacitor for creating a differential voltage in the input circuit of the differential amplifier is connected by a discharge circuit to the silicon controlled rectifier so that the voltage on the capacitor is discharged every time the silicon controlled rectifier is conductive.

Pulse control circuit for a dc load

Abstract: A circuit for providing controlled pulses of direct current to vary the speed of a direct current motor. A main controlled rectifier applies current to the motor. A commutation circuit consisting of an inductor, a capacitor and another controlled rectifier turns off the main controlled rectifier by reversing its polarity. Another circuit, referred to as a ''''ring-around'''' circuit, consisting of another inductor and controlled rectifier reverses the polarity of the commutating capacitor preparatory to the commutation of the main controlled rectifier.

Demodulator for magnetic milling force sensors

Abstract: An improved system is provided for sensing spindle deflection of a milling machine and developing a feedrate control signal in accordance therewith to achieve optimum tool life consistant with high metal removal rate from a workpiece. A plurality of magnetic transducers are disposed adjacent the spindle or spindles of a milling machine, and each magnetic transducer is excited by an audio frequency signal such that, as deflection of a spindle brings the spindle closer to or moves it further from a transducer, a corresponding change in the impedance characteristics of the transducer is utilized to develop an a-c signal of a given amplitude. Signals developed from opposing transducers are fed to a differential amplifier to derive a difference signal which is demodulated by a phase detector, rectified and filtered, and then passed through a squaring circuit in order that signals corresponding to the square of the deflection sensed by each transducer pair may be mixed to provide a d-c voltage representing the sum of the squares representing the deflection components. The square root of the sum of the squares is then taken to give a feedback signal proportional to the vector sum of spindle deflection for utilization as a feedrate correction signal. For milling machines utilizing multiple spindles simultaneously, a peak detector circuit is utilized to select the largest sum of the squares only for subsequent development of the feedrate correction signal. Changes in the resistance of the magnetic transducers due to temperature variations encountered under normal operating conditions are compensated by placing the coil of each magnetic transducer in a series circuit which includes a field effect transistor biased to perform as a variable resistor responsive to a change in current flow through the coil by presenting an apparent resistance which opposes the change in current. Runout, which introduces an invalid deflection signal component by modulating the audio frequency reference signal according to the rate of spindle rotation, is compensated by observing the signal produced by runout from each tool holder, tool combination prior to machining, and then providing a continuous equal and opposite signal thereby leaving only the component due to actual spindle deflection. This signal also compensates for component drift. This function is carried out by a loop including a d-c amplifier which drives an A-D converter which, in turn drives a D-A converter which has its output coupled back to the input of the d-c amplifier. When activated, the calibrate circuit introduces trial signal levels until the output of the d-c amplifier is zero, thus negating the effect of runout.

Temperature compensation for magnetic milling force sensors

Abstract: An improved system is provided for sensing spindle deflection of a milling machine and developing a feedrate control signal in accordance therewith to achieve optimum tool life consistant with high metal removal rate from a workpiece. A plurality of magnetic transducers are disposed adjacent the spindle or spindles of a milling machine, and each magnetic transducer is excited by an audio frequency signal such that, as deflection of a spindle brings the spindle closer to or moves it further from a transducer, a corresponding change in the impedance characteristics of the transducer is utilized to develop an a-c signal of a given amplitude. Signals developed from opposing transducers are fed to a differential amplifier to derive a difference signal which is demodulated by a phase detector, rectified and filtered, and then passed through a squaring circuit in order that signals corresponding to the square of the deflection sensed by each transducer pair may be mixed to provide a d-c voltage representing the sum of the squares representing the deflection components. The square root of the sum of the squares is then taken to give a feedback signal proportional to the vector sum of spindle deflection for utilization as a feedrate correction signal. For milling machines utilizing multiple spindles simultaneously, a peak detector circuit is utilized to select the largest sum of the squares only for subsequent development of the feedrate correction signal. Changes in the resistance of the magnetic transducers due to temperature variations encountered under normal operating conditions are compensated by placing the coil of each magnetic transducer in a series circuit which includes a field effect transistor biased to perform as a variable resistor responsive to a change in current flow through the coil by presenting an apparent resistance which opposes the change in current. Runout, which introduces an invalid deflection signal component by modulating the audio frequency reference signal according to the rate of spindle rotation, is compensated by observing the signal produced by runout from each tool holder, tool combination prior to machining, and then providing a continuous equal and opposite signal thereby leaving only the component due to actual spindle deflection. This signal also compensates for component drift. This function is carried out by a loop including a d-c amplifier which drives an A-D converter which, in turn drives a D-A converter which has its output coupled back to the input of the d-c amplifier. When activated, the calibrate circuit introduces trial signal levels until the output of the d-c amplifier is zero, thus negating the effect of runout.

Circuit for accurately controlling the amplitude of a transmitter

Abstract: A circuit and system for controlling the amplitude of a transmitter wherein a variable gain amplifier receives the output of the transmitter and is controlled by a differential amplifier which receives inputs from a pair of rectifiers. One of the rectifiers receives a signal from the variable gain amplifier and the other rectifier receives an input from a low frequency oscillator whose output is supplied to the rectifier through a pair of variable attenuators which allow accurate adjustment of the input to the rectifier. One of the variable attenuators may change the amplitude of the signal in relatively large steps and the other variable attenuator accomplishes fine settings.

Voltage regulator for dc power source

Abstract: In a DC power source in which a silicon controlled rectifier is connected in series with a DC circuit of a single phase AC bridge rectifier so that the phase of the firing angle may be controlled to control the load voltage upon the armature of a D.C. motor, a saturable reactor is inserted in series with the AC power source of said bridge rectifier.

Ferroresonant battery charger circuit

Abstract: A circuit for charging a storage battery is disclosed which uses a ferroresonant transformer in combination with a full-wave rectifier to supply direct current to charge the battery. The charging current is controlled by a single silicon controlled rectifier connected to substantially short circuit either all or a portion of one secondary winding of the transformer during increasing portions of half cycles of one polarity as the battery becomes charged. A voltage divider applies a preselected portion of the alternating current transformer output voltage, which is essentially the battery voltage, to gate the controlled rectifier. This preselected voltage is modified by the resistance varying characteristics of a thermistor which is responsive to heat produced by current through the controlled rectifier when it is conducting to reduce the current supplied to the battery. A lamp may be provided to visually indicate when the battery is charged.

Tv afc circuit eliminates biased diodes for symmetrical pull-in

Abstract: The automatic frequency control (AFC) system of a television receiver includes a discriminator network and a pair of nonbiased rectifier arrangements with load circuits, operating over a small range of frequency deviations centered about the desired mean frequency. The rectifier arrangements are non-biased for compatibility with varactor tuning systems and include three serially connected diodes in one of the rectifier arrangements and a single diode in the other to achieve extended pull-in. The three serially connected diodes vary the conduction threshold of the positive portion of the discriminator network to assure proper shaping of the frequency response characteristic of the FM detector. Accordingly, for conditions of gross mistuning, control voltages are obtained from the two rectifier arrangements that are of the same polarity and aid one another in obtaining an augmented frequency correcting effect.

Static type electric circuit breaker

Abstract: A single-phase full-wave type rectifier bridge is respectively provided within selected phases of A.C. line conductors and in series therewith to provide for the switching of an A.C. load current. Each rectifier bridge has four arms two of which respectively include a main thyristor and the other two arms of which respectively include a main diode. Additionally, the rectifier bridge functions such that one of the main thyristors passes a positive half wave of current therethrough, the other main thyristor passes a negative half wave of current therethrough, one of the main diodes becomes conductive during a positive half wave of the current and the other of the main diodes becomes conductive during a negative half wave of the current. A reactor is connected across the D.C. output terminals of the rectifier bridge for conduction of the load current. A series combination of a commutating capacitor and an auxiliary thyristor is connected between an intermediate connection point of the main thyristors of the rectifier bridge and other terminals of the main thyristors through an auxiliary diode. The commutating capacitor is normally charged from an auxiliary D.C. voltage supply and is discharged to negatively bias the main thyristor which is conductive when the auxiliary thyristor is turned on when a circuit-interruption is required.

Capacitor discharge ignition system testing apparatus

Abstract: A potentiometer with leads interconnects to the conventional 12 volt battery. The potentiometer tap is connected to the capacitor charging terminals of a capacitor discharge ignition system with a meter for setting to a selected charging level. A test switch grounds connects the controlled rectifier gate for discharging of the capacitor through the ignition system pulse transformer. A relatively large dropping resistor in series with a low voltage selection potentiometer is connected to the transformer. A self-controlled rectifier has its gate connected to the selection potentiometer tap in series with a diode. An output circuit including a lamp and a low voltage battery responds to the selective triggering of the test rectifier.

Fail-safe pulsating peak detection circuit

Abstract: This disclosure relates to a fail-safe peak detector for detecting the presence of pulsating input signals and for providing an output signal which is proportional to the peak values of the input signals. The detector includes an amplifier having its input transformer coupled to the input signals and having its output transformer coupled to a bridge rectifier which is coupled to the coil of an electromagnetic relay which in turn controls an electrical contact of an indicating circuit.

Three-phase rectifier converter

Abstract: A three-phase high voltage rectifier converter is disclosed which comprises rectifier element, three double-winding saturable reactors and a supply of transformer whose secondary windings of each phase together with two windings of different reactors connected in opposition, form series circuits, the series circuits forming a three-phase system obtained by interconnecting the end leads from the reactor windings and the rectifier elements are connected to the leads from the three-phase system in such a way that when the series circuits are arranged in a star the rectifier elements are joined to the leads from the secondary windings of the supply transformer, whereas when the series circuits are arranged in a delta whose junctions are formed by the like leads from the two windings of each of the reactors the rectifier elements are connected to the junctions of the delta.

Peak detector circuit

Abstract: A circuit which changes state to produce a different output signal level at the peak of a substantially periodically varying analog input signal whereby the peak of the input signal is detected and indicated.

Silicon controlled rectifier tester

Abstract: The silicon controlled rectifier tester employs an oscilloscope, a grounded-grid amplifier, a clipping circuit and a pair of cathode followers to rapidly test the operating characteristics of silicon controlled rectifiers. The oscilloscope provides a sawtooth signal voltage which is amplified and applied to a rectifier which is under test. The oscilloscope also provides a record of the operating characteristics of the silicon controlled rectifier.

Rectifier circuit using mos field effect transistor

Abstract: A rectifier circuit, comprising the combination of a MOS field effect transistor and an amplifier, in which non-linearity in the input a-c voltage versus output d-c current characteristic in the low voltage region, such as encountered in the conventional diode rectifier circuit, is improved, thus realizing linearity down to millivolt range.

Power rectifier including a bridge rectifier circuit

Abstract: A power rectifier comprising a bridge rectifier circuit and a choke coil for supplying a rectified current to a load wherein said choke coil is divided into two portions respectively inserted in two arms of the bridge circuit to be connected to one terminal of an AC power source, and rectifier means inserted in the other two arms to be connected to the other terminal of the AC power source are utilized not only to flow the rectified current to the load, but also to discharge an energy stored in the load depending on its impedance.

Test circuit for measuring figure of merit or attenuation ratio of vibrating systems

Abstract: A test circuit for measuring the attenuation ratio of vibrating systems comprises a vibrating system connected to an amplifier in turn connected to a detector responding to average value, and a peak detector connected in parallel to the average detector. The outputs of the two detectors are connected to an adder whose output is applied, through a voltage-to-frequency converter, to a pulse circuit whose outputs are connected to an exciting circuit, to the amplifier and to an integrator.

IMPATT Diode Amplifier

Abstract: : A high performance IMPATT diode test circuit was developed which is very effective in reducing spurious oscillations of the diode under test by controlling the impedance presented to the diode by the circuit. In this circuit, a 10 GHz silicon diode was tested as an amplifier with power gains in excess of 20 db.