Abstract: An alarm circuit to monitor a periodic signal source for an occurrence of a short-circuit condition detects the entry of the instantaneous periodic signal magnitude into a predefined window bounded by an upper and lower threshold. The duration of the entry is timed to determine if a short circuit has occurred.

Abstract: A circuit for indicating the approximate energy content of the most significant transient appearing on an electrical power line within a predetermined interval is disclosed. An input to a first threshold comparator (326) may be set by the user to mark the nominal minimum amplitude (V.sub.2 ) of voltage transient whose energy content (volt-second area) is to be recorded. The transient impulse voltage integrator (401) is turned on when the impulse amplitude exceeds a preliminary threshhold (V.sub.1) lower than the nominal amplitude (V.sub.2) under control of a second comparator (325) and flip-flop (423). When the transient impulse amplitude equals the nominal amplitude (V.sub.2), a latch (431) reading a digital converter (430) at the output of the integrator (401) is clocked to permit display of the accruing integrator. While the integration proceeds the threshold of the second comparator (325) is increased from V.sub.1 to V.sub.

Abstract: A circuit for ascertaining the direction of origin of the most significant transient appearing on a electrical power line within a predetermined interval is disclosed. Threshhold comparator circuit (325, 326) are provided to insure that transient polarities needed for the directivity determination are ascertained while the transient impulse is still rising towards its peak value. For any nominal, user-set threshhold (V.sub.2), a lower preliminary threshold (V.sub.1) is automatically set and when the transient exceeds the preliminary threshhold, the transient polarities are determined and correlated to effect a tentative directivity determination which is stored in an input latch (205). When the transient exceeds the nominal threshhold, the directivity determination is transferred to an output latch (211) to be read by an output printing device.

Abstract: Apparatus for monitoring and controlling the operation of a dual platen press used in the manufacture of nuclear fuel pellets is disclosed. The apparatus includes means for indicating the displacements of both platens and imposing the displacements of the platens on orthogonal axes such that the displacements jointly control the motion of a point which traces a lissajous figure representative of the displacement and relative velocity of the press platens. A second lissajous figure representing the desired platen movements and relative velocity may be superimposed on the first lissajous figure, differences between the first and second lissajous figures indicating deviations from the desired operation of the press. Alternately, a press operator may simply use the first lissajous figure constructed from the actual platen displacements to analyze the operation of the press. The completion of preselected portions of the first lissajous figure may be detected and used to trigger subsequent press operations.

Abstract: A method of counting the number of load current pulsations in an alternating current supply including monitoring the alternations of the supply current and detecting pulsations thereof by detecting suitable falls of the pulsations following the rises thereof, creating upon detecting a pulsation a discrete signal therefor, said signal creation being powered from said pulsation, and counting the discrete signals to determine the number of pulsations.

Abstract: A sensor-recorder for recording a representation of the direction and peak amplitude of a transient current. A magnetic thin film is coated on a glass substrate under the influence of a magnetic field so that the finished film is magnetically uniaxial and anisotropic. The film is split into two oppositely magnetized contiguous domains with a central boundary by subjecting adjacent portions of the film simultaneously to magnetic fields that are opposed 180.degree.. With the split-domain sensor-recorder placed with the film plane and domain boundary either perpendicular or parallel to the expected conductive path of a transient current, the occurrence of the transient causes switching of a portion of one domain to the direction of the other domain. The amount of the switched domain portion is indicative of the amplitude of the peak current of the transient, while the particular domain that is switched is indicative of the direction of the current.

Abstract: A method of and circuit for monitoring the amplitude of a sine wave-shaped electrical signal in a defined range of a signal period, wherein the signal is derived from scanning an object which is to be measured or controlled. A comparison circuit is provided which compares the signal being monitored to a reference signal and generates a first impulse signal which is applied to a logic gate. A second impulse signal generating network generates a second impulse signal determining the range of the signal period by adding at least one signal derived from additional signals contained in the signal spectrum to the signal being monitored. This impulse is also applied to the logic circuit. The logic circuit produces a switching signal for operating an indicator or control device.

Abstract: A method is provided for detecting the presence of arcing faults in the stator windings of large dynamoelectric machines, such as turbine generators. Arcing faults, such as broken strands in a winding conductor with continued arcing, give rise to high frequency currents which flow in the neutral lead of the generator winding. The presence of the arcing fault can thus be detected by observing the high frequency neutral currents and monitoring them for the presence of the characteristic frequency distribution resulting from the resonance characteristics of the current path.

Abstract: A circuit for determining on a half-wave cycle basis the maximum and minimum voltages of input cyclic line voltages for selected time periods in which the line voltages are rectified to half-waves, and an integrating voltage to frequency converter provides output pulses proportional to the voltage magnitudes of the half-waves with the pulses being counted and placed in a memory and then compared with minimum and maximum previous counts for previous half-waves, to provide an updated minimum and maximum voltage for such half-waves over a period of time or period of half-waves, with provisions for providing resetting strobe pulses at zero voltages of the half-waves and for providing accurate measuring of the pulse outputs in the integrating voltage to frequency converter by modulating the integrator sense voltage and achieving substantially accurate compensation for the effects of timing errors in the V/F converter.

Abstract: A probe for developing a visual indication of the electrical state of a selected point in a digital circuit under test. The probe is provided with two clips for attaching to the power supply and the ground of the circuit to be tested. The operator then holds a sharp tip of the probe at the selected point at which the electrical condition of the circuit is to be tested. Two light emitting diodes visible on the probe body display which one of the six possible circuit conditions exist at the selected point, such as open circuit, positive-going pulse, negative steady-state and so forth. The circuit utilizes integrated circuit NOR and inverting buffer components. Pulses as short as ten nanoseconds may be detected. The probe may be used with any voltage range of the various logic circuit families.

Abstract: A current detecting apparatus wherein when a wire is energized, a reed switch comes into operation in response to the magnetic lines of force generated concentrically around the wire to detect the presence of a current flow in the wire. The current detecting apparatus may be easily attached on and removed from a wire.

Abstract: An apparatus for measuring the intensity of current produced in an elongated electrical conductive member by a lightning strike for determining the intensity of the lightning strike. The apparatus includes an elongated strip of magnetic material that is carried within an elongated tubular housing. A predetermined electrical signal is recorded along the length of said elongated strip of magnetic material. One end of the magnetic material is positioned closely adjacent the electrically conductive member so that the magnetic field produced by current flowing through said electrically conductive member disturbs a portion of the recorded electrical signal directly proportional to the intensity of the lightning strike.

Abstract: For detecting faults on low voltage alternating current electric power distribution cables, recorders are provided, each triggered by a selected occurrence, e.g. a decrease in signal amplitude or a change in the waveform, to cease recording, after a short delay, of the waveform data in digital form, so that a store holds digital data enabling the waveform of the last few cycles covering the period before and after the selected occurrence. Using a voltage gradient technique analysis of the data enables the position of the fault to be located.

Abstract: An apparatus for monitoring, analyzing and accurately determining the value of peak current, the peak rate of change in current with respect to time and the rise time of the electrical currents generated in an electrical conductive mast that is located in the vicinity where lightning is to be monitored. The apparatus includes an electrical coil for sensing the change in current flowing through the mast and generating a voltage responsive thereto. An on-site recorder and a recorder control system records the voltages produced responsive to lightning strikes and converts the voltage to digital signals for being transmitted back to the remote command station responsive to command signals. The recorder and the recorder control system are carried within an RFI proof environmental housing into which the command signals are fed by means of a fiber optic cable so as to minimize electrical interference.

Abstract: Apparatus for evaluating a measurement signal having an initial transient issuing into a more stationary value include equipment for monitoring the rate of change of the measurement signal. This monitoring equipment issues a control signal when that rate of change falls below a predetermined value. An analysis of the measurement signal is initiated in response to the latter control signal.Apparatus for evaluating at least two measurement signals generated by two transducer probes and having mutually overlapping initial transients issuing into more stationary values at different times include equipment for determining the time sequence wherein the measurement signals issue into the more stationary values. The measurement signals are sequentially applied to evaluating equipment in accordance with that determined time sequence.

Abstract: Bipolar signals used in binary or ternary data transmission, arriving at a receiving station, are periodically sampled under the control of sync pulses extracted from the incoming data train. The samples are rectified and stored on a capacitor whose voltage variations, upon rectification and integration, yield an indication of signal distortion during transmission. The average capacitor charge furnishes a feedback signal for keeping the voltage variations proportional to signal amplitude. A threshold circuit prevents the sampling of zero or near-zero voltages with ternary signaling.

Abstract: There is provided a device for detecting corona discharges generated in a high voltage generator which is operated by high frequency pulses, for example in a high voltage transformer which is used in the horizontal deflection circuit of a television receiver.

Abstract: An improved testing device and method to measure the degree of polarization potential on the interface of a metal structure and its environment where said structure is protected against corrosion through a cathodic protection system.The testing device includes adjustable stop means associated with a conventional electrometer to reduce the excursion of the needle of said meter and thereby achieve a more accurate reading of the polarization potential of the metal structure.

Abstract: An apparatus for measuring and displaying the sag and surge voltage values of an AC power supply. Two inputs are attenuated, filtered and the peak difference is converted to a binary number by an analog-to-digital (A/D) converter. A digital comparator compares these conversions with the values stored in a maximum and minimum register. If the output of the A/D is larger than the contents of the maximum register, the previous maximum register's contents are replaced by the A/D output. If the output of the A/D is smaller than the contents of the minimum register, the previous minimum register's contents are replaced by the A/D output. Dual light emitting diode displays provide a numerical readout of the contents of the maximum and minimum registers.

Abstract: An electronic system is disclosed which examines the first derivative of an applied electrocardiographic (ECG) signal, recognizes the R-wave event therefrom, and discriminates against signal components which lie outside predetermined signal parameters in producing a rectangular pulse output. In addition, muscle artifact and pacers are discriminated against. The system includes an automatic gain control to eliminate the need for operator controls.

Abstract: A line voltage monitor for monitoring the voltage applied to electrical equipment and for providing an indication or protective disablement of the equipment in the event excessive variations occur in the line voltage. The line voltage monitor includes a steady state voltage sensing means and a transient voltage sensing means for detecting both types of voltage variations.

Abstract: A transient direction detector which indicates the occurrence of power line ransients and their direction of propagation. The system is comprised of current and voltage sensors, a logic and control circuit which receives the transient current and voltage sensed and provides an output to an indicator circuit to show the direction of any transients on a power line. The current sensing circuit receives an input from an induction coil on an iron clamp around a power line. The voltage sensing circuit receives its input from a voltage sampling transformer directly connected across a power line. The logic and control circuit determines where the transient occurred by comparing the polarity received from the transient current and voltage sensing circuits.

Abstract: A detector for locating the direction of propagation of transients on eleical power lines supplying critical loads having various types of random impulse voltage transients. The device detects the polarity of transient voltages and the direction of transient current. An integrated logic and control circuit compares the sampled voltage and current to indicate from which direction the transient came. The logic and control circuit activates indicator lights which show whether the transient occurred in the direction of the source or the load and whether the transient was positive or negative.