Abstract: The detection of brief pulses generating high frequencies is carried out by a system including: sensor for detecting an electrostatic field and for detecting an electromagnetic field, such that the variation of the electrostatic field ocurring in a period of time of less than 1 millisecond may be identified. A signal activator for warning about the presence, in an interval of time of less than 1 millisecond, of the variation of the electrostatic field detected and of the electromagnetic field, allowing identification of a pulse due to an electrostatic discharge from furniture or human beings. The invention is applicable to the detection of pulses due to electrostatic discharges.

Abstract: A high voltage measuring circuit for broadband measurement of transient signals occurring in high voltage apparatus. The measuring circuit is housed in a shielded housing having an input sensing circuit for connection to a capacitive grounded tap of the high voltage apparatus. The sensing circuit is connected to an output circuit through an electrical shielded connection. The measuring circuit generates output signals which are replicas of the transient signals appearing on the bushing of the high voltage apparatus. The broadband of the measuring circuit extends over a frequency range of from about 1 Hz to 1 MHz and has a signal level higher than background noise.

Abstract: A digital peak and valley detector including a peak value address register, a valley value address register, a peak value data register, a valley value data register, a peak comparator for comparing the value stored in the peak value data register with value data contained in the digital signal applied to the digital peak and valley detector and for causing the greater of the two to be stored in the peak value data register while simultaneously storing the address in the peak value address register and a valley comparator for comparing the valley value contained in the valley value data register with the value data contained in the digital signal applied to the digital peak and valley detector for determining which is less and for causing the value and the address of the smaller of the two to be stored respectively in the valley value data and the valley value address registers.

Abstract: The measuring circuit comprises an integrator to which a signal representative of the current flowing through the primary winding of the output transformer of an inverter is applied. The integrator output signal is reset at the beginning of each period of the A.C. component of said current and is applied to a sample and hold stage whose output signal represents the integrator output signal just before it is reset. An intermediate stage is arranged between the integrator and the sample and hold stage to reduce the influence of load impacts by limiting the maximum possible variation of the output signal during the sampling period.

Abstract: A peak to peak or two-point voltage difference measuring equipment according to the present invention comprises: a control circuit; a D/A converter for converting the digital data given from the control circuit into the reference analog voltage; a comparator for comparing an input voltage signal with a reference analog voltage; means for gating the output of the comparator for a predetermined time segment interval; and means for holding the output of the gating means and applying to the control circuit.

Abstract: An index signal generation timing control system of this invention comprises a rotation signal generating section which generates a rotation signal representing the rotational state of a customer engineer (CE) disk set on a spindle. A burst signal generating section generates a burst signal from burst data written on the CE disk. A measuring section measures the time from time when an index signal becomes active to time when the burst signal is generated by the burst signal generating section. A calculation control section subtracts a predetermined time from the measured time and determines delay time data corresponding to the subtraction result. The determined delay time data is written in memory at the address that is generated in accordance with a write control signal from the calculation control section.

Abstract: A device for detecting voltage fluctuation including a first amplifier for amplifying an input voltage signal, a second amplifier for amplifying the same input voltage signal with a fixed delay time relatively to the first amplifier and a voltage comparator for comparing the respective amplified output voltages to produce a high-level output at the time of increase or decrease of the input voltage signal.

Abstract: A predictive time base control circuit for a waveform sampling system of the type which converts a sequence of analog waveform samples into a sequence of digital quantities for storage in an addressable acquisition memory. The time base circuit generates a sampling control signal which initiates sampling at the end of a time interval of programmable duration following detection of a triggering event in the waveform, and which maintains sampling thereafter at regular intervals. The time base circuit permits the sampling system to operate in an equivalent time mode in which repetitive waveform sections are sampled at progressively skewed sampling intervals with respect to a repetitive triggering event. The sampling control signal is also frequency divided, delayed, and then applied as a write control signal to the sampling system acquisition memory.

Abstract: An adaptive filtering procedure reduces overshoot which may be present on a waveform having infinite slopes displayed on a digital oscilloscope as a result of interpolation between samples at the location of the infinite slopes. An adaptive filtering procedure identifies sampled points adjacent the infinite slope and moves the points closer to each other to avoid ringing or overshoot on the display. Before modification, a straightness test relative to the waveform before and after a discontinuity and a test for sudden changes in the waveform before and after the discontinuity are performed.

Abstract: This invention relates to an index signal generator for a magnetic disk drive. The peak of the magnetic field from the magnet during rotation in association with the rotation of the spindle is detected by a peak detecting circuit. A detection pulse signal output circuit outputs a detection pulse signal synchronously with the peak of the magnetic field on the basis of the result of the detection of the peak detecting circuit. A memory for storing adjustment data is provided. This adjustment data corresponds to the time after the detection pulse signal was output until the index pulse signal is output. An index pulse signal output circuit outputs the index pulse signal on the basis of the adjustment data stored in the memory after an expiration of a period of time corresponding to the adjustment data from the output of the detection pulse signal.

Abstract: The direction of change of an analog signal which is digitally displayed on a digital display can be immediately determined at a glance by providing a change-display in the vicinity of the digital display, which digitally displays the analog signal value. The change-display displays whether the analog input signal is increasing or decreasing by comparing the present value of the input signal with a previous value thereof. This comparison may be effected by integrating the input signal and comparing the integrated input signal with the input signal or by differentiating the input signal or by using a sample and hold circuit to hold a previous input signal value which is then compared with the present input signal value.

Abstract: Centralized control receiver for power distribution networks, includes an input section containing at least one digital filter, an evaluating device, and an output section, the digital filter having a frequency response effecting selective damping of harmonic frequencies of at least one of the frequency of a respective network and control frequencies of at least one of adjacent centralized control services and of network-specific interference frequency ranges.

Abstract: A monitoring system and apparatus is employed to duplicate unique environmental conditions at a first location so that sensitive electronic devices can be tested at a second location. Initially an environment recorder is plugged into the AC line at the first location. Line voltage characteristics including transients are then captured on tape. The environment recorder has the ability to record and respond only to unusual environmental conditions. The tape of the environment recorder is subsequently removed to a second location, typically the manufacturer's laboratory, where it is played back through the same or another environmental recorder into a reproduction line driver. Output voltages produced by the reproduction line driver exactly mimic the environmental conditions at the first location. The duplicated output is fed into the sensitive electronic device which might be a computer or other sensitive instrument to see how it responds to the simulated electronic conditions from the first location.

Abstract: A transient detector apparatus utilizing peak and slope detectors to determine the presence of transient signal in a logic signal. Individual slope measurements of the input signal are compared with a logic criteria to establish the occurrence of a transient. The peak voltage and pulse width of a transient are digitized in order to time tag or isolate a transient to a particular signal.

Abstract: A pair of flat cable transmission lines are monitored for transient current spikes by using a probe connected to a current transformer by a pickup loop and monitoring the output of the current transformer. The approach utilizes a U-shaped pickup probe wherein the pair of flat cable transmission lines are received between the legs of the U-shaped probe. The U-shaped probe is preferably formed of a flat coil conductor adhered to one side of a flexible substrate. On the other side of the flexible substrate there is a copper foil shield. The copper foil shield is connected to one end of the flat conductor coil and connected to one leg of the pickup loop which passes through the current transformer. The other end of the flat conductor coil is connected to the other leg of the pickup loop.

Abstract: A noise removal circuit for use in partial discharge measuring device of a high voltage apparatus. The circuit includes a first phase shift/reduction device responsive to an input signal for passing it directly while delaying it by a predetermined time and for reducing the delayed signal from the directly passed signal a second phase shift/reduction device for passing an output of the first phase shift/reduction device directly while delaying the output by the predetermined time and for reducing the delayed signal from the directly passes signal, and a phase shift/multiplying device for directly passing an output signal of the second phase shift/reduction device while delaying it by a time twice the predetermined time and multiplying the directly passed signal with the delayed signal.

Abstract: A detector for indicating the occurrence of a surge current in the ground return conductor of a lightning arrestor or other monitored conductor includes two clamps which establish electrical connection with the conductor at two spaced locations along its length. A rectifier circuit develops an actuator signal from the voltage induced between the two locations to activate an electromechanical counter or indicator flag. The clamps are installable on the conductor without access to the ends thereof to facilitate installation of the detector on an existing conductor.

Abstract: A waveform disturbance detection apparatus for detecting disturbances in alternating current electromagnetic energy waveform, the alternating current electromagnetic energy waveform having a plurality of periodic, substantially similar cycles. The detection apparatus comprises converter means for sampling the electromagnetic energy waveform, generating a plurality of samples, and converting the samples into digital signals. The detection apparatus also comprises processing means for evaluating the digital signals so as to detect disturbances in the electromagnetic energy waveform, wherein the processing means detects the disturbances by comparing a particular one of the digital signals that represents a particular one of the samples in a particular one of the cycles with a corresponding one of the digital signals that represents a corresponding one of the samples from the remaining cycles.

Abstract: An electronic apparatus is proposed for detecting variations of significance in an electrical voltage as a function of time. The apparatus includes a tracker (2) of these variations, a comparator (6) comparing the voltage with a reference voltage V.sub.2, and a counting circuit (10, 15, 20). The tracker (2) monitors variations in the voltage supplied to a filtering and rectification system (4), which eliminates the continuous component of the signal and within the high frequency range greatly diminishes the levels of the parasitic signals having an oscillatory character. The comparator (6) furnishes a calibrated pulse (25) each time the voltage exceeds the threshold V.sub.2, and the counting circuit (10, 15, 20) counts the number of these calibrated pulses within a given time period T and furnishes a logic signal (30) if this number exceeds a predetermined quantity.

Abstract: A noninterruptive noise measurement technique wherein the absolute value of the amplitude error from a modem slicer is compared to a reference, the number of events in excess of said reference over a selected interval are counted and the range within which said count falls is determined as a particular signal to noise ratio value.

Abstract: An impulse measurement system for displaying impulses in an alternating current electromagnetic energy waveform, the impulses generally occurring at frequencies substantially greater than that for the waveform. The system comprises high speed sample memory for recording the high frequency impulses, memory for recording the waveform, and display for receiving the high frequency impulses and the waveform from the high speed memory and the waveform memory, respectively, and displaying both the high frequency impulses and the waveform simultaneously, thereby permitting efficacious identification of the cause of the impulses.

Abstract: An apparatus for indicating the level of digitally encoded audio data, in which a set of bits representing the audio signal amplitude are periodically latched in a latch circuit, with the resultant output bit signals from the latch circuit being displayed by means such as LED elements, with the period of repetitive latching operations being made to vary in accordance with the audio signal level, such as to increase in response to increases in that level.

Abstract: A raster display digital oscilloscope includes an analog to digital converter and a memory array for developing and storing a digital measurement signal amplitude-dependent on an acquired input signal. After processing stored digital signals are conveyed to an output circuit which includes a raster-scanned CRT and three display memory planes independently addressable by the CPU for receiving in discrete address locations the digital data. Corresponding address locations in the three planes are read in synchronism with the CRT scan to develop a display signal for application to the CRT to produce a display corresponding to the sum of the data stored in the three planes. The digital signals are automatically spread out or bunched up within the display planes to compensate for differences between the data acquisition rate and the scan rate.

Abstract: A method of detecting hazardous line voltages over a two-wire line for transferring digital information. At one end, the line is terminated by a hybrid coupler (G) and an apparatus for adaptive echo elimination. This apparatus generates a digital signal (d) constituting an unambiguous measure of the difference between the line impedance (Z.sub.L) and the hybrid impedance (Z). This signal is compared with two digital limiting values (d.sub.1,d.sub.2) an alarm being given should either these two values be reached or exceeded.

Abstract: A high frequency electromagnetic field detector for detecting high frequency electromagnetic fields comprises a micro antenna for mainly receiving the induction term of the electromagnetic field, an amplifier for amplifying a voltage induced on the antenna, a comparator circuit for comparing the output of the amplifier with a predetermined reference level to output a signal indicating that the output exceeds the reference level, and an indicator in response to the signal from the comparator circuit for indicating it.

Abstract: An oscilloscope vertical amplifier with Boolean combinatorial trigger generator capability is disclosed. While the display output is fully analog, the trigger output to the time base is digital with a user selectable Boolean function of the analog input signals. Also included is nested triggering, edge as well as level sensitivity, and a trigger filter to selectively inhibit high frequency events. The delay times of the analog and digital signal paths are matched by means of analog delay lines before presentation by a visual display to present the analog and digital signals in time coincidence to the oscilloscope main frame.

Abstract: A transient detector system for monitoring a voltage signal to detect positive and negative transient voltages on the voltage signal that penetrates a predetermined threshold band, the transient detector system being synchronized to an internal clock signal and providing first and second output signals characterizing the amplitude of the last largest respective positive transient noise signal and the last largest negative transient noise signal penetrating a threshold band. The transient detector system also provides third and fourth output signals characterizing the pulse widths of both the last largest positive and last largest negative transient noise signals. The transient detector system receives a sampled and digitized signal characterizing the instantaneous amplitude of the signal and uses a positive and negative threshold detect circuit means to recognize the presence of transient noise signals.

Abstract: A metal oxide type surge arrester is provided with a plurality of arrester blocks in series within a housing having, in addition to line and ground terminals at the extremities, a bushing providing a tap voltage terminal intermediate the series stack such as between the bottom two arrester blocks. The provision of the voltage tap and a shunt resistance in series with the ground terminal permits respectively detecting the voltage and the current of the arrester so that they can be compared and their phase relation observed to determine if the arrester blocks are maintaining a capacitive characteristic or have become resistive. In addition, several other methods of use of such an arrester for monitoring line voltage, energy absorption, fault current and the like are disclosed.

Abstract: A spark monitor device arranged to detect a high frequency noise due to a spark generated in a current collector of a rotary electric machine and monitor a state of spark generation on the basis of the product of a peak value of the high frequency noise exceeding a given set value and a time interval during which the peak value exceeds the set value.

Abstract: A method and apparatus for automatically detecting peak values of an applied unknown electrical signal employ a binary search technique in which a digital signal is converted to analog reference voltage levels one bit at a time from the most significant bit to the least significant bit to be compared with the unknown signal until finally a digital signal is produced which corresponds to a peak value. By selecting and controlling the comparator slope, both positive and negative peaks may be detected. The search for positive and negative peaks of signals occurring in one or more signal channels may be interleaved to decrease total detection time. From the detected values, a triggering voltage level may be arithmetically computed.

Abstract: The DC content of an AC waveform is detected by a digital filter which partially filters each phase of the waveform and applies the filtered waveforms sequentially through a multiplexer to a sample and hold circuit which measures the instantaneous value of each phase at two points which are spaced an exact odd number of half cycles apart. The time interval between the measurement points is adjusted according to variations in the AC waveform frequency to maintain required spacing. The measured instantaneous values are fed by an analog to digital converter and to a microprocessor system which averages the two readings to generate a signal corresponding to the DC content for each phase.

Abstract: In a method of geophysical prospection a transmitter dipole and a receiver dipole which is sensitive to an electromagnetic field are positioned in cooperation with the subsoil. An impulsive excitation current is applied repeatedly to the transmitter dipole, the excitation current comprising a group of pulses of alternate polarity, each followed by zero current. The transient signal, which is produced thereby at the output of the receiver dipole, is repeatedly detected, and the transient signals are processed to obtain a figurative representation of the transient phenomenon which facilitates geophysical interpretation. Time intervals which are consecutive to excitation pulses and simultaneously with the excitation zero current are defined, these time intervals being of a predetermined duration, chosen to substantially cover all the useful parts of the transient phenomenon.

Abstract: A lightning arrester comprises nonlinear resistance discs 2 stacked within a ceramic casing 1, with annular metal cover rings 3, 4 being fixed to the opposite outer ends of the casing. Conductive plates 5, 19 having reduced thickness rupturable central portions are sealed to the inner ends of the casing, with the lower plate 19 being insulated from the lower ring 4 by an insulating ring 20. An ammeter 16 is connected between the conductive plate 19 and ground by a lead wire 21 passing through the ring skirt but insulated therefrom, whereby only leakage current passing through the nonlinear resistance discs is sensed.

Abstract: An apparatus for measuring varying current levels is particularly suited to the measurement of distinct current pulses. The apparatus couples by means of an inductive sensor to a current carrying conductor. A current pulse in the conductor induces a voltage within the sensor, which is then converted by a unipolar voltage to frequency converter to a sequence of electrical pulses, the total number of which is proportionate to the peak current value of the pulse. The number of pulses produced may be displayed as a measurement of the peak current pulse; in a preferred embodiment, the apparatus compares the number of pulses to a pre-set alarm value, enabling the apparatus to signal any occurrence of current pulses over a desired value.

Abstract: The DC content of each phase of a three phase AC waveform is generated by partially filtering each phase and applying the filtered waveforms sequentially through a multiplexer to a sample and hold circuit which measures the instantaneous value of each phase at two points which are spaced an exact odd number of half-cycles apart. These instantaneous values are fed by an analog to digital converter into a microprocessor which averages the two readings to generate the DC content for each phase and compares the highest DC content with a threshold value. The excess of the highest DC content over the threshold value is integrated and an output signal is generated when the accumulated volt-seconds exceed a selected value.

Abstract: Departure of a logic signal from the ranges of signal values corresponding to defined logic levels is monitored by comparing the logic signal with the boundary values of these ranges. Provided the logic signal between transitions is below the lower threshold (14) or above the upper threshold (12), a NOR gate (16) and a D-type bistable circuit (18) open an AND gate (22) to enable a counter (24) to count 10 MHz clock pulses. If the logic signal is between the thresholds, the AND gate disables the counter. The four most significant digits of the total number of clock pulses actually counted after 1,000,000 have been supplied is displayed, giving an indication of the percentage of time for which the logic signal has a value corresponding to a defined logic level. As an alternative, the output signal of the NOR gate (16) can be inverted (26) and supplied to a moving-coil or digital voltmeter (30).

Abstract: A method and device for the contactless measuring of direct and alternating current, in particular current instantaneous values, by using a magnetic circuit having an air slot and a magnetic field dependent resistor through which a control current flows and a winding through which a measuring current flows. In order to provide a large measuring speed for picking up a rapid instantaneous value, for example, generated high current peaks, at least a further winding is mounted on the magnetic circuit, the voltage drops on the magnetic field dependent resistor are picked up and stored at the peak values or other typical values of the current to be measured. After completing the measuring current, the current in the equivalent current winding is increased and the already stored voltages corresponding to the measuring current are compared consecutively with the voltage drops on magnetic field depending resistor, corresponding to the increase in the amount in the equivalent current winding.

Abstract: The level and duration of RF current flowing in the neutral grounding circuit of a generator is monitored to determine internal arcing conditions.

Abstract: A power supply control circuit is especially useful for a traveling wave tube, although it may also be used anyplace where desirable. An a-c power voltage is supplied to an input of the control circuit, where its frequency is multiplied to become a voltage having a period which is no greater than the duration of a power voltage fluctuation which might damage the traveling wave tube, unless corrected. The wave form of the multiplied frequency is shaped to provide a comparison voltage wave form, which is compared with a reference voltage. The a-c power voltage applied to said traveling wave tube is controlled responsive to the output of the comparison means.

Abstract: A system for measuring and storing the amplitudes plus duration and/or rise times of overvoltage pulses occurring on a transmission line comprises a voltage divider working into a first and a second comparator respectively detecting an abnormal voltage exceeding a predetermined sensitivity threshold and discriminating among different amplitude levels above that threshold. The first comparator triggers an oscillator driving a pulse counter which measures the duration of an overvoltage pulse and also provides quantized information on rise time to the highest amplitude threshold surpassed by that pulse as determined by the second comparator. This information is stored in a memory with two groups of cells respectively assigned to combinations of amplitude with duration and combinations of amplitude with rise time, the occurrence of any such combination incrementing the contents of the respective cell.

Abstract: Method and apparatus for sequentially scanning a plurality of target elements with an electron scanning beam modulated in accordance with variations in a high-frequency analog signal to provide discrete analog signal samples representative of successive portions of the analog signal; coupling the discrete analog signal samples from each of the target elements to a different one of a plurality of high speed storage devices; converting the discrete analog signal samples to equivalent digital signals; and storing the digital signals in a digital memory unit for subsequent measurement or display.

Abstract: A system for digitizing transient signals comprises a plurality of high-speed sampling gates connected in parallel to a common input terminal, these gates working in interleaved relationship into respective charge-transfer devices each including a multiplicity of storage cells which are successively loaded in a first operational phase with analog samples delivered by the corresponding gate. After having been fully loaded, the several transfer devices are read out cell by cell in a second operational phase via a multiplexer into an analog/digital converter at a rate which is substantially lower than the sampling rate.

Abstract: A shunt is disposed in the current path of a device, e.g. a magnetic particle machine and an input voltage from the shunt is amplified and coupled to: a peak-hold circuit for developing a digital amperage readout; and, a pulse comparator circuit operative with clock, clock gate and counter circuits for developing pulse length readout.

Abstract: Inrush current measuring apparatus with an instantaneous power interruption device is provided an external power input terminal connected to a commercial power supply and an external power output terminal connected to a power unit under test, which terminals are connected together via a switching circuit section; and is equipped with a power interruption device in which the power supply from the external power input terminal to the external power output terminal is cut off or conducted by opening or closing the switching circuit section.

Abstract: A transient signal processing circuit is disclosed which includes a signal input, an adjustable threshold detector for selecting from the signal input a signal portion having at least a minimum amplitude, a peak value detector connected to the threshold detector for providing an output when the signal portion reaches a maximum amplitude, a monostable multivibrator connected to the peak value detector to introduce a time delay and thereby allow the output to stabilize, a sample and hold circuit connected to the multivibrator to record the value of the maximum amplitude, and a clock connected to the multivibrator to indicate the time at which the maximum amplitude was attained.

Abstract: An instrument of the type employed to measure the conduction angle of the ignition coil of the battery-powered ignition system of an internal combustion engine comprises input connectors which are connected to terminals of such ignition system and an evaluating circuit which generates a signal corresponding to the conduction angle to be measured by ascertaining whether an input signal derived from the input connectors rises above or falls below a predetermined threshold voltage level. For differing types of conventional ignition systems, differing threshold voltage levels are required, but instead of resorting to manual switchover to such different levels, the instrument of the invention modifies the threshold voltage level employed in automatic dependence upon the value of the input signal derived by the input connectors. The threshold voltage level assumes a first value when coil conduction ceases and a second value when coil conduction recommences.

Abstract: In a system for quality control evaluation of energized electrical power sources, a waveform analysis apparatus and method is employed permitting greatly increased capability for the detection, measurement and evaluation of the signal characteristics, especially the noise signal, of the tested units. A high-speed magnetic tape recorder stores the output signal of the unit under test. A high-speed AC-to-DC converter receives the output noise signal and inputs it to a fast-responding, track-and-hold peak detector. The peak level output signal of the peak detector may be displayed for any desired time interval and the peak detector reset resulting in discrete time interval printouts of peak noise output. Noise levels of interest may be rapidly located and a complete display of the power source output signals during that time interval of interest obtained from the magnetic tape recorder allowing detailed waveform analysis.

Abstract: A waveform acquisition circuit for both real-time and equivalent-time acquisition modes with a smooth transition between modes. The circuit includes a control circuit which causes an analog-to-digital converter to take samples of an analog waveform in precise time relationship with preselected data points along the time axis of the waveform. The data points may be preselected in accordance with a variable increment.

Abstract: Apparatus for measuring the amplitude of an adjustable width current or voltage impulse at a known time interval following the initiation of the impulse. During a first pulse duration, a counter is advanced with clock signals having a frequency f.sub.1. The total number of clock signals accumulated during the interval is then transferred into a downcounter which is arranged to be decremented during a second identical interval by a clock signal having a frequency n (f.sub.1). When the downcounter reaches zero, a strobe pulse is produced for enabling the analog measuring circuits which sample the amplitude of the current or voltage impulse being monitored. By selecting the value n, the sampling point can be shifted in time along the width of the pulse being measured. For example, for n=2, the amplitude of the voltage or current pulse being measured will be that occurring at the midpoint of the pulse.

Abstract: A sampling circuit and method therefor including a first Josephson junction or producing a series of sampling pulses for activating a second Josephson junction that is receptive of both the analog current signal being sampled and a bias current. The first Josephson junction is continually triggered at a fixed time relative to the repetitive analog signal to provide a series of sampling pulses and before each sampling pulse the bias level to the second Josephson junction is changed until the sum of the current from the sampling pulse, from the analog signal, and from the bias source exceeds the critical current value of the second Josephson junction causing it to switch from one voltage state to another. The value of the bias current at the point of switching is proportional to the current in the analog signal.In one embodiment, the bias current is increased in a step-like fashion for each sampling pulse from the first Josephson junction until the critical value of the second Josephson junction is reached.