Abstract: A digital speedometer for indicating angular or linear velocity has an index counter to control update of the displayed velocity. The purpose of the index counter is to prevent undesirable fluctuation of the displayed velocity where minor variations in velocity being measured have occurred. The digital speedometer uses a pulsating input signal having a frequency proportional to the velocity to be indicated. An oscillator circuit provides a clock frequency that is utilized in generating a counting period electrical signal. During the counting period, the input pulses proportional to velocity are gated into a counter. After each counting period, a comparison is made between the count currently being displayed and the count stored in the counter. If a difference occurs, the index counter is incremented. Only after the index counter has been incremented a plurality of consecutive times is the display permitted to be updated.

Abstract: An electronic tachometer, for use in a disk drive system, to sense velocity of an accessing head mechanism relative to data tracks being accessed, comprises a first feedback loop comprising a variable bandwidth differentiator for receiving a position signal and providing a velocity signal; and a second feedback loop including the differentiator and means for supplying a control voltage to said differentiator in response to a variable velocity signal provided by the differentiator.

Abstract: A remote speedometer-tachometer for the measurement of the rpm's of an engine and the speed of the craft containing the engine is provided, having first and second adjustable voltages which are related to the pitch of the engine with the sound moving toward and away from an observer. A multiplier is provided for modulating the first voltage by the second voltage and applying the output therefrom to an oscillator for controlling the frequency of the oscillator. An output transducer means is coupled to the oscillator, making it possible for the observer by adjusting the first and second voltages to match the output of the transducer with that of the sound from the engine, the settings of said first and second voltages being calibrated to provide the speed of the craft in which the engine is mounted and/or rpm measurement for the engine.

Abstract: An apparatus is provided which produces an alarm signal when the magnitude of a varying physical quantity such as the running speed of an automobile, for example, exceeds one of a plurality of preset threshold values. The apparatus includes detection means having a plurality of detection channels in which mutually different threshold values are defined and capable of producing an electrical output in response to the magnitude of the varying physical quantity exceeding a threshold value in each of the detection channels; selection means for selecting one of the threshold values and for providing an output signal indicative of the selected threshold value; and comparison and control means for comparing the output from the detection means and the output from the selection means to produce an electrical output when the magnitude of the physical quantity exceeds the threshold value selected by the selection means.

Abstract: A magnetic core velocity transducer is attached to a metallic base plate by means of non-ferrous support elements. Relative movement of the coil over the core of the velocity transducer, during impact of a driven pile to which the base plate is rigidly attached, generates a voltage at the transducer terminals which is proportional to the relative velocity between the core and the coil.

Abstract: In an anti-skid brake control system for a wheeled vehicle, an electronic circuit for generating a wheel speed signal in accordance with the time duration of a half cycle of a sinusoidal waveform generated by a sensor that detects the presence or absence of teeth of a rotor that revolves with a wheel of the vehicle is arranged so that the measured time duration of both a positive and a negative alternation of the waveform is utilized to obtain accurate wheel skid control at relatively low speeds. Slight differences in the measured time duration of a positive and negative half cycle due to slight variations in the dimensions of a tooth and adjacent space are sensed and modified as required to assure correspondence between the measured time durations in order to avoid false sensing of a wheel skid condition.

Abstract: In a circuit for producing a digital wheel speed signal from the duration of a half cycle alternation of the sinusoidal waveform produced by a wheel sensor, there is provided a control unit which operates a first counter until it reaches a count corresponding to the duration of the half cycle alternation of the sinusoidal waveform and in response to this occurrence effects operation of a second counter until the first counter reaches a predetermined final stage. A signal representing the duration of a half cycle alternation, which is inversely proportional to the angular wheel velocity is thus converted by the control unit so as to produce a wheel speed signal that is directly proportional to the angular wheel velocity. According to the present invention, the pulse frequency supplied to at least one of the first and second counters is adjusted according to the stage of the counter so as to change exponentially and thereby provide for faster generation of the wheel speed signal.

Abstract: A digital circuit for generating an error correction or otherwise characterized signal having a value which changes in accordance with a second signal such as the speed of an airplane (MACH). As a specific example, the generated signal is indicative of the error correction required to the static and derived pilot tube pressure signals which error correction changes non-linearly with respect to the velocity of the airplane. Since, in general, each type of airplane requires its own special correction signal, the apparatus must be readily alterable to a given specific application.

Abstract: A voltage controlled oscillator provides a pulse signal which, when frequency scaled, is representative of aircraft velocity. Pulses representative of passage of the aircraft over distance intervals are coupled to one input of a comparator-integrator, and the VCO output pulses are further divided and coupled to the other input terminal of the comparator-integrator. The integration voltage controls the VCO. The VCO signal is frequency scaled and fed to a counter, the output count of which is strobed periodically and decoded to yield velocity.

Abstract: A mathematical expression is converted and approximations applied to remove complex processes, simplifying the circuitry of system which controls compressor speed in dependence on ambient temperature.

Abstract: The instant system describes a heading and attitude reference system for an aircraft in which slaving of the directional gyro to the magnetic compass and roll erection of the vertical gyro is cut off during turns which exceed a predetermined rate. A unique feature of the system is the manner in which the turn rate cutoff rate signal is generated from the directional gyro without incorporating either rate gyros or rate generators. The turn rate cutoff signal is generated from the directional gyro heading signal by converting the heading signal electrically into a signal proportional to turn rate. In one embodiment, the heading signal from the directional gyro which is representative of the heading shaft angle (.theta.) is converted into a plurality of signals proportional to the sine and cosine of shaft angle .theta.. These signals are first differentiated and then vector summed to produce a signal directly proportional to the rate of shaft rotation (d.theta.

Abstract: A velocity measurement apparatus using pulsed ultrasonic waves which includes a transmitting section which projects pulsed ultrasonic waves to a target at a predetermined position and a receiving section which detects echoes from the target and the Doppler shift. The transmitting section, in order to remove undesirable echoes, causes the polarity of the ultrasonic pulse to be changed at random and the receiving section removes the undesirable echoes by using the irregular polarity of the pulsed ultrasonic echoes.