Abstract: A motor speed sensor for sensing the RPM speed of a motor is designed to be placed in line with a conventional mechanical tachometer take-off. The motor speed sensor includes rotatable shafts interconnecting the mechanical tachometer take-off so that the mechanical delivery to the tachometer is preserved and further includes a notched interrupter which rotates in cooperation with the interconnecting shafts. The notches of the interrupter are disposed to rotate between a photo-electric detector and a light source thereby interrupting the beam of light in order to provide a stream of output pulses whose frequency is directly proportional to the speed of the motor.

Abstract: A digital tachometer having an optical sensor which provides a signal at a frequency related to the rotational or reciprocating speed of a moving object, a phase locked loop and a frequency divider circuit connected for operation as a frequency multiplier to be responsive to the sensor signal to provide a serial pulse train the period of which is an integral multiple of the sensor signal, a pulse accumulator for registering the pulses and a time rate generator which enables the pulse accumulator to register pulses for a preset duration so that the number of pulses registered is a direct representation of the revolutions per minute of the moving object.

Abstract: A speed measurement system for converting signal pulses directly into a 13 bit binary number for input to a digital processor is disclosed. The signal pulses are generated as a function of incremental shaft rotation. A plurality of additional pulses are injected in the pulse train between successive displacement or signal pulses, such that a stream of equally spaced pulses is produced at a predetermined speed. The number of generated displacement and injected pulses are counted during predetermined time intervals for providing a direct speed measurement.

Abstract: A combination speedometer/odometer apparatus for displaying either the speed of a vehicle or the distance a vehicle has traveled, and including a speed pick-up attached to the vehicle for developing a first voltage signal having voltage spikes occurring at a frequency proportional to the speed of the vehicle; a pulse generator which develops a voltage pulse in response to each spike, the pulses having a predetermined duration; a signal generator controlled by the voltage pulses which develops a speed signal and a distance signal both having bursts of high-frequency signal, the number of bursts in the speed signal being proportional to the speed of the vehicle and the number of bursts in the distance signal being proportional to the total distance the vehicle has traveled; a first counter for counting the cycles of the speed signal, the counter initiating its count in response to a reset signal; a synchronizer for developing the reset signal a predetermined period of time after the occurrence of one of the vol

Abstract: A tachometer for measuring and comparing the angular velocity of a first and a second wheel of a vehicle includes means for sensing and generating a train of pulses for each of the wheels wherein the repetition rates of the pulse train varies in proportion to the angular velocity of the wheel. For each of the wheels a frequency doubler is provided for doubling the repetition rate of the pulse train of the varying repetition rates having pulses of the same pulse width and amplitude. For each wheel the frequency doubled pulse train is then integrated to provide a DC output. The two DC outputs for the two wheels are then compared, selected and applied to corresponding output terminals of the tachometer.

Abstract: A digital tachometer provided with a measuring shaft to be brought into contact with a rotating body to be measured for simultaneous rotation therewith. As the shaft is rotated the number of rotations of the rotating object is digitally indicated and the indication remains even after the measuring shaft has been moved out of contact with the rotating object under measurement.

Abstract: A disk rotatably connected to an associated vehicle's speedometer cable has a plurality of holes evenly spaced around its circumference. The number of holes is a function of the number of revolutions the speedometer cable makes in a given distance traveled by the vehicle. The holes allow a beam of light to fall on a phototransistor. The phototransistor generates electrical pulses per unit time numerically proportional to the angular velocity of the disk and thus to the speed of the vehicle. The function relating the number of holes on the disk to the number of revolutions made by the speedometer cable per a given distance is chosen to make the number of pulses generated per a given time equal to or an integral multiple of the speed of the vehicle expressed in some standard system of speed measurement. Logic circuits divide the output pulses by said multiple and store the resulting number. This stored number is then directly displayed and is equal to the speed of the vehicle in terms of the standard system.

Abstract: A system is disclosed for detecting the state of a rotating machining tool, such as a drill bit, in a machining head. The system employs an electromagnetic detector having a coil connected in series with an oscillating circuit. As the tool rotates, its lands and flutes cause detectable variations in reluctance which are used to modulate the output of the oscillator circuit. The modulated oscillator output is monitored as an indication of the state of the tool.

Abstract: The disclosed meter comprises a pulse shaper circuit for forming each input pulse into a voltage pulse having a predetermined pulsewidth, a level control circuit connected to the pulse shaper circuit to produce a voltage including a dc component providing a measure of the frequency of the input pulses, and a low-pass filter dc coupled to the level control circuit. The filter consists of a series resistor, a parallel capacitor and a series feedback type operational amplifier to extract the dc component from the voltage from the level control circuit.

Abstract: A digital tachometer for generating electrical pulses at a rate indicative of the speed of rotation of a shaft-like member. A first toothed disk having N teeth is affixed to the shaft and a housing having a second set of M teeth is fixed with respect to the shaft and positioned around the toothed disk. As the shaft rotates, individual ones of the teeth on the outer periphery of the disk which is affixed to the rotating shaft alternatively pass into and out of close proximity to individual ones of the teeth of the outer housing resulting in periodic increases and decreases in the reluctance of the system. A sensing coil is positioned with respect to the housing so as to generate an electrical current which varies as the reluctance changes from one polarity to another as the shaft rotates.

Abstract: A sensing circuit using a polarity discriminator with feedback means for selecting one polarity component of a bi-polar non-symmetrical waveshape signal input, while rejecting the opposite polarity component. The circuit operates on both the amplitude and the frequency characteristics of the input signal, to produce an output signal responsive to these characteristics. The circuit may be used to process signals generated from toothed wheels by electromagnetic sensors, or the like, typically used in tachometer control.

Abstract: A tachometer for generating a digital output signal representing velocity which is a stepped approximation to a 1/t velocity versus time curve where t is the time required to travel a fixed distance. High resolution is obtained by dividing the 1/t curve into octaves and an approximate straight line portion. A nonlinear counter counts a predetermined number of pulses during each octave as the time of the counting interval for succeeding octaves is doubled. Therefore, the counter total and the number of octaves completed after time t represents velocity. After completing eight octaves, the nonlinear counter counts at a predetermined frequency to generate a straight line approximation of the 1/t curve as it approaches zero velocity. The digital output can be converted to analog form by a digital-to-analog converter and operational amplifiers having an amplification factor determined by the number of octaves completed.

Abstract: A method and apparatus for determining the rotational speed of an engine, using electrical pulses produced with revolving parts of the engine, including the use of a number of series of transducers or pickups producing numbers of asynchronous pulses, different for each series during each revolution of the engine, the transducers corresponding to as many series of detection elements comprising teeth and/or bosses spaced on the periphery of corresponding revolving parts of the engine, such that if n is the number of detection elements of a largest series giving the highest pulse frequency for a corresponding transducer due to engine revolution, and q is the total number of transducers associated with another series of detection elements, then the angular location of said another series of detection elements is obtained to the nearest 360.degree./qn.

Abstract: The invention relates to a device for signalling the rotational displacement or speed of a shaft provided with a rotary seal through which a gas or liquid is induced into a bore within the shaft. More particularly, the invention relates to a novel device in which the operative elements of a rotary seal and a rotational transducer are combined as a compact unitary assembly that is simple, reliable and easily serviced.

Abstract: An averaging circuit for producing average boat speed and average apparent wind speed which in cooperation with average apparent wind direction are utilized to determine the performance characteristics of sailing boats. Instantaneous values of the speed parameters are sampled at a predetermined frequency and a running average of N samples is generated by adding the most recent sample and discarding the oldest sample at periodic intervals. Display of the wind speed is delayed with respect to the display of boat speed to compensate for the effect of the inertia of the boat.

Abstract: Apparatus for measuring the angular movement of a body comprises a tranducer for providing a signal the frequency f.sub.i of which is dependent on the angular velocity of the body and a reference frequency source providing a reference frequency f.sub.r. An (n + m) stage binary counter is provided for counting the number of reference pulses in time period 1/f.sub.i and an (n + m) stage binary store receives a count from said counter when the latter receives a signal from the transducer. The apparatus also includes an n-stage binary rate multiplier having a first input for receiving the n least significant figures of the store, and a second input for receiving an output signal from the apparatus, the rate multiplier being arranged to generate, during the period in which the rate multiplier receives 2.sup.n binary pulses at said second input, a number of output pulses which is equal to the number of pulses applied to said first input,.