Abstract: A radio frequency coupled differential sensor coil is configured to measure uzzle velocity of a projectile with improved accuracy. An inner loop of the sensor is positioned to be responsive only to the passage of the projectile and the inner and outer loops are equally responsive to exitation from extraneous sources. A differential amplifier circuit is utilized to cancel the extraneous source signals and amplifying the pulse signal generated by the passage of the projectile through a confined radiation plane.

Abstract: A muzzle velocimeter comprising a pair of sensors positioned adjacent to the path of a projectile containing magnetic material wherein each of the sensors includes a permanent magnet having a wire coil wound thereon. The magnets provide magnetic fields which are disturbed by magnetic materials in a passing projectile causing each of the sensor coils to develop signal pulses. The distance between the sensor coils and the amount of time between the sensor coil pulses are used to calculate the velocity of the passing projectile. In an alternate embodiment a single sensor coil is used to sense the leading and trailing edges of a passing projectile, and the projectile velocity calculated by using projectile length and passing time of the projectile.

Abstract: A synchronizing circuit is disclosed which enables a desired phenomena to occur, such as the discharge of a flash illuminating means at a precise point along the path of travel of an article irrespective of the speed of the article in that path.The circuit utilizes two spaced sensors upstream of the precise point. The sensors are operable to detect the passage of the article and each sensor is connected to respective counter. When sensor detects the passage of the article it starts its respective counter counting in one direction at one particular counting rate. When the second sensor detects the passage of the article it causes its respective counter to count in the opposite direction from the value of the count in the first count at a different but faster counting rate. The circuit includes gate means which determine when the count has returned to a predetermined count to then cause said phenomena to occur.

Abstract: A machine has two relatively movable portions and relative movement between the portions is sensed by means generating an electric current. In the preferred embodiment this means comprises a permanent magnet on one portion and an induction coil and a soft-iron core on the other portion. The two portions are parts of an overload coupling interconnected with a shear pin. When the coupling is overloaded, a shear pin fractures and the two portions rotate relative to one another. This causes a current to be generated in the coil which actuates a signal element. The device provides a visual indication of the operative condition of the two portions.

Abstract: A vehicle such as a speedboat or racing car is equipped with a magnetic sensing coil (22) for producing electrical signals in response to detection of magnets disposed at one or more positions along the course. In the case of buoy-mounted markers, the magnets (26) may be mounted on certain of the buoys (10,13,14,17). The output from the sensing coil (22) is used to control on-board timing circuitry to enable the average vehicle speed over the course to be determined and displayed.

Abstract: The measuring apparatus enables measuring the muzzle velocity V.sub.o of projectiles, especially sabot projectiles, wherein the sabot disintegrates immediately after departure out of the muzzle of the weapon barrel. For this purpose two measuring coils, by means of which there can be measured the muzzle velocity of the projectiles, are secured to a sleeve member which prevents disintegration of the sabot prior to the V.sub.o -measurement.

Abstract: A transducer for measuring the velocity and displacement of ferromagnetic materials comprising first and second magnetic read-heads positioned close to but not contacting the magnetic element whose velocity is to be measured with the two read-heads located a fixed distance apart in the direction of travel of the element, magnetic means positioned close to the magnetic element ahead of the first and second read-heads in the direction of travel of the magnetic element for increasing the magnetic surface noise levels of the material or the magnetic element, amplifiers connected to the two read-heads for amplifying the random voltage noise signals induced in the read-heads, said signals being substantially identical with one being delayed in time with respect to the other, zero-crossing detectors connected to the outputs of the amplifiers, means for correlating the noise signals obtained from the zero-crossing detectors and providing an output frequency signal, an electronic digital delay line circuit connected b

Abstract: A system controlling apparatus wherein an array of sensors are used for detecting information and for providing signals indicative of information concerning passing articles such as presence of an article at a sensor, number of articles passing, the direction of passing and the velocity of passing. Signal processing apparatus is comparing the signals with pre-determined parameter information as to the system and for providing control to the system in response to detecting equality and for providing overriding control to the system in response to detecting inequality. Each of the sensors is self-checking during the period an article is not present.

Abstract: A rotating speed detecting device of a turbocharger comprising the compressor wheel and the turbine wheel which are fixed onto the opposed ends of the rotary shaft. A hole is formed on the central portion of the shaft. An electromagnetic detector is arranged in the vicinity of the central portion of the shaft so that the detecting head of the detector can face the hole of the shaft.

Abstract: An electronic velocimeter for measuring the muzzle velocity of a projectile mploys a conductive coil mounted between the muzzle and an annular conductive shield. The shield and coil are insulated from each other and encircle the trajectory of the projectile. An oscillator means for generating an oscillator signal is coupled to the coil. This oscillator means is responsive to the projectile passing through the coil. A timing means responds to the oscillator to produce a timing signal. This timing signal represents the transit time for the projectile to traverse a predetermined interval of the trajectory of the projectile. Knowing this transit time the velocity is readily obtained.

Abstract: A system and method for measuring the rotational speed of a variable speed drive shaft for a ship or the like with high accuracy over a wide range of speeds. Means associated with the shaft sense the time interval for each turn of the shaft, or fraction thereof. Such time interval is accurately measured and then converted to an r.p.m. value. Steps in the method include counting the number of cycles of an oscillating signal in binary form to measure the time interval for each turn, selecting a most significant portion of bits within the number counted, determining the positional weight of the most significant bit to obtain a scaling factor, and producing a voltage inversely proportional to the value of the selected portion of bits, which voltage is then scaled by the scaling factor.

Abstract: A D.C. motor comprises a permanent-magnet stator including a flux-return structure and at least one permanent-magnet stator magnet mounted on the flux-return structure and also an armature mounted for rotation within the stator and having a circumferential succession of armature teeth. The rotary speed of the armature during operation of the D.C. motor is ascertained indirectly by sensing the variations in the stray flux of the motor at the exterior of the flux-return structure.

Abstract: A sewing machine incorporates a ferrous member connected to a rotating part of the machine and a magnetic perception head disposed such that during operation of the machine the member moves towards and away from the head. Pulses produced by the head are fed to a counter which gives the total number of pulses and thus an indication of the total operating time of the machine and of the number of stitches made.

Abstract: A signal generating mechanism for producing a pulsed DC electrical voltage signal having a frequency proportional to the angular velocity of a rotating shaft. The signal generating mechanism may be used in the distributor of a breakerless ignition system for a multi-cylinder internal combustion engine, in which case the frequency of the pulsating voltage signal is equal to the rate at which ignition sparks are to be generated. The signal generating mechanism includes a baseplate and a bushing through which the rotating shaft passes. A stator assembly is formed by a hub and lower and upper plates affixed thereto, the stator assembly being rotatable about the bushing and further including at least one Hall effect sensor and integrated circuit mounted in a nonmagnetic supporting structure secured to the upper plate. A permanent magnet also is attached to the supporting structure and is radially spaced from the Hall effect sensor and integrated circuit.