Abstract: An apparatus is provided for the detection and counting of the number of lightning discharges on the skin of an aircraft. The apparatus comprises a sensor electrode for the detection of such discharge, an electronic circuit for generating and shaping a pulse at each detection interval, and a circuit for counting and displaying such pulses.

Abstract: An electrical conductivity indicator has a bridge circuit which is supplied from a source of electronic oscillations preferably successive half cycles being of reverse polarity and having electrodes in a cup arranged to be hand held below the teat of a cow so that the presence or absense of Mastitis infection is indicated by the variations in electrical conductivity of the milk held in the cup.

Abstract: A calculator for computing the estimated time of arrival of a vehicle or the like at a desired destination. The calculator, under control of a microprocessor and related interfacing devices, computes and periodically updates the estimated time of arrival at the destination from information reflecting present chronological time, the total estimated distance and the desired average speed to be travelled to the destination, and the actual distance travelled by the vehicle. The information resulting from the microprocessor's computations is visually displayed together with the present chronological time. The calculator may also be provided with warning sensors to provide an indication when a predetermined maximum speed has been exceeded. In an alternate mode, the calculator may be caused to function as a standard four function calculator, without affecting data previously stored in the estimated time of arrival mode.

Abstract: The eddy-current testing device operates by translational motion of a probe within the interior of tubes to be tested. The probe comprises in succession from front to rear in its direction of normal translational motion a front guiding member, a coil-carrying member and a rear guiding member connected together by an elastic means which tends to maintain these three members in aligned relation. At least the coil-carrying member has maximum transverse dimensions which are smaller than the internal diameter of the tube. An emitter-receiver coil of the probe is connected electrically to an external supply and scanning system by means of a cable which is secured mechanically to the rear guiding member.

Abstract: A method of signal analysis in which the signal in digital form has range values and domain values at successive turning points of range values stored in a memory; upon the signal passing through a penultimate stored value of range, the last two stored values of range and associated domain values are extracted for separate use and are deleted from the memory and hence from subsequent comparisons.

Abstract: An optical transducer having concentric radiant beam detectors for converting a radiant beam to electrical signals including a first axially placed detector with a second detector concentric therewith. In one embodiment, the detectors receive the radiant beam through an amplifying auxiliary lens. Changes in focus differentially affect the magnitude of the beam impinging on the individual detectors, resulting in corresponding changes in the individual detector outputs.A focusing system employing the transducer moves a focusing lens in response to the differential output of the individual detectors. The focusing system can be employed in a video disc reading system so that the video disc scanning beam is always focused precisely at the disc. An electrical difference circuit leading from the photo-detectors generates a driving signal to energize a lens-moving motor for shifting the focusing lens along the axis of the beam.

Abstract: Apparatus for the measurement of mass throughput in a flowing medium comprises a conduit between the pole pieces of an electromagnet which produces polarizing and resonating fields. The pole pieces are shaped to provide a first section in which the separation of the pieces is relatively small and a second, shorter section in which the separation is greater. The single magnet thereby produces different flux densities for polarizing and inducing nuclear resonance respectively and an improved signal-to-noise ratio by the application of a polarizing field which is more intense than the resonating field.

Abstract: The present invention relates to an indicator arrangement for indicating the condition of a phase locked loop. The indicator comprises a flip-flop having its two input terminals connected directly to the input terminals of the phase detector of the phase locked loop in a manner such that under a lock condition the signal at the first input terminal of the flip-flop will be advanced in phase from the signal at the second input terminal. Under such condition a first output signal will be generated at a first output terminal of the flip-flop to activate a "lock" indicating device. When out of lock, the signal at the second input terminal of the flip-flop will be advanced in phase to the signal at the first input terminal and (a) a second output signal will be generated at the first output terminal causing deactivation of the indicating device, and (b) a first output signal will be generated at a second output terminal to activate a no-lock indicating device when desired.

Abstract: A level sensor for an air-spring shock absorber is sensitive to the axle-to-body distance of the vehicle on which the shock absorber is mounted. The level sensor comprises a thin support plate formed of resilient material that may be deformed to fit within the shock absorber in conformity with the shape of the inner surface of the tubular member defining the air spring. The support plate has an LED mounted on one end, and first and second photoresistors mounted at the other end in spaced relation to one another; the first and second photoresistors representing the upper and lower limits of permissible axle-to-body distance, respectively. Light communication between the LED and photoresistors is established or interrupted by the absence or interposition of a fluid reserve tube therebetween. A connector head is integrally formed with the support plate and is insertable through a hole in the tubular body defining the air chamber to secure the sensor in position.

Abstract: An electronic recorder is disclosed which acts as an elapsed time indicator for monitoring the operation of at least one item of equipment and providing display or other indication of the total time for which the item of equipment has been energized. The recorder includes a solid-state oscillator and a divider which together constitute a time-base for producing clock pulses only when the item of equipment is in an energized state. A solid-state counter counts the clock pulses and a solid-state memory stores information corresponding to the counter total. So that the recorder can retain its cumulative total count even when de-energized with the item of equipment, the memory is of the non-volatile type which retains its stored information even when de-energized. A solid-state display means displays the counter total to provide an indication of the total time for which the item of equipment has been energized.

Abstract: An optically pumped magnetic resonance gyroscope wherein the direction of the magnetic fields intersecting the absorption cells of two interconnected spin generators may be oriented in the same or opposite directions, but are of unequal magnitude. The output from each spin generator comprises signals having frequencies characteristic of the two isotopes contained in the cell of each spin generator. These signals are applied to filter circuits each of which passes a desired frequency. Two signals are multiplied in frequency. A pair of phase difference sensors measure differences in phase between pairs of filter outputs, and controls the spin generators in such a manner as to return a first function of the phase differences to null. The output signal from the instrument, derived from a second function of the phase differences, represents the angular rotation of the gyro about a predetermined axis.

Abstract: A signal monitoring device useful to monitor power consumption level employs a phase locked loop and an associated frequency reduction circuit to convert relatively low frequency input pulse signals to an output signal representative of power consumption.

Abstract: An all digital circuit converts a signal of an unknown frequency into an accurate binary representation of that frequency. The apparatus consists of an all digital closed loop system which has as its input the unknown signal. The closed loop system generates a reference signal and forces the frequency thereof to approximate that of the unknown signal. In so doing, the closed loop generates a binary number representative of the frequency of the reference signal and provides this number as the system output.

Abstract: Electronic sensing and measuring equipment for accurately measuring the pitch of musical sounds and which includes an audio tuner responsive to the fundamental frequency of a continuing signal while rejecting all other harmonically related components of said signal to produce a digital signal representing the fundamental pitch of said musical sound, and a counter for counting and totalizing said digital signal defining the same in terms of its frequency and for visually displaying said defined signal.

Abstract: Frequency measuring apparatus wherein a single sideband modulator is fed by an input signal, the frequency of which is to be determined, and a reference signal having a predetermined frequency f.sub.o to produce upper and lower sideband frequency signals separated in frequency by 2f.sub.o. A delay line shifts the phase of one of such signals .phi. relative to the other one of such signals, such phase shift being related to the frequency of the input signal. The signals are then combined and detected to produce a signal having a frequency 2f.sub.o and a phase angle related to the phase shift .phi.. A phase comparator, responsive to the reference signal and the later produced signal, detects the phase of the later signal thereby providing an indication of the frequency of the input signal. With such an arrangement relatively fewer and less costly devices may be used for the frequency measuring apparatus.

Abstract: A method and system for testing the accuracy of the oscillators of electronic clocks includes transforming a frequency signal corresponding to the output of a clock oscillator into a non-sinusoidal signal having the same frequency as the frequency signal and filtering the non-sinusoidal signal to pass a component of the non-sinusoidal signal having a frequency associated with a reference frequency to be compared with the signal passed by the filter such that clock oscillators operating at various frequencies of which the reference frequency is an integral multiple can be tested since the non-sinusoidal signal, which is preferably a sawtooth signal, contains harmonic components corresponding to the reference frequency.

Abstract: Digital instrumentation for waveform measurement including method and apparatus for providing irregularly spaced sampling times to prevent misleading visual patterns of coordinate points due to the presence of signal frequencies above the Nyquist frequency. The method and apparatus includes means for plotting coordinate points having abscissa positions corrected according to actual irregular sampling times, method and apparatus whereby irregularities are repeated for each signal sweep, and method and apparatus utilizing a bit reversal system to achieve the irregularly spaced sampling times.

Abstract: A photoelectric detection system which has two sequential photoelectric receivers to determine the precise moment at which the boundary between two contrasting fields passes beneath the detectors irrespective of the relative contrast between the two fields. The signals from the two photoelectric detectors which change as the boundary progressively obscures their respective fields of view are firstly subtracted to produce a difference signal. The difference signal is then passed to a gated maximum value store which is operative during each difference pulse to store the maximum value of the difference occurring during that pulse. A fraction of this maximum value is then taken and compared with the instantaneous value of the difference as this value reduces, when these two values are equal an output pulse is generated and this output pulse always occurs at the same position of the boundary relative to the photoelectric receivers irrespective of the respective levels of contrast on either side of the boundary.

Abstract: Apparatus for controlling an odometer and speedometer system of a vehicle, adjustable for vehicle parameter variations, such as tire size and axle ratio, including a transducer for generating a plurality of initial pulses in response to vehicle movement which pulses control both the vehicle odometer and speedometer. The initial pulses are multiplied by a multiplying factor to produce a train of pulses for each initial pulse. The multiplying factor is in binary form and is selected either according to the position of an array of switches or according to a number retained in a programmable downcounter. The train of pulses is divided by a fixed number to create a driving signal for the odometer and is converted by a frequency converter to drive the speedometer.

Abstract: Method and apparatus for determining the hematocrit of blood samples from the electrical conductance of whole blood by means of a portable, simple to use instrument with a digital readout. A dip-electrode-probe and/or a "fingerstick"-probe, requiring one drop of blood, have been developed to provide an easy to use and clean electrode system. Electronic improvements further provide for uniformity of readings between observers, automatic operator alert when poor sample contact or insufficient battery power, an exponential solution to the Fricke, Curtis and Maxwell equations and further eliminates electrode polarization by providing a separate DC path to conduct any DC component in the sine-wave signal. A provision is also made to estimate the hemoglobin value from the measured hematocrit.