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Patent

Delay line signal detector

About: The article was published on 1963-12-24. It has received 9 citations till now. The article focuses on the topics: Phase detector characteristic & Detector.
Citations
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Patent
24 Sep 1987
TL;DR: In this paper, a magnetostrictive wire is used to measure liquid level as a function of the elapsed time between an actuation signal and the first zero crossing of the voltage which is induced as the torsional strain passes through the area of influence of the sliding magnet.
Abstract: A liquid level detector of the type in which a magnetostrictive wire extends through the liquid level measurement range and is captured in a tensioned vertical orientation within a stainless steel tube. Liquid level is measured as a function of the time required for a torsional disturbance imparted the wire near the top to travel along the wire to a magnet which is contained within a liquid level float which slides up and down along the tube. The torsional disturbances imparted to the wire by means of a piezoelectric crystal to which the wire is easily clamped. Accuracy is enhanced by measuring liquid level as a function of the elapsed time between an actuation signal and the first zero crossing of the voltage which is induced as the torsional strain passes through the area of influence of the sliding magnet.

55 citations

Patent
03 Apr 1989
TL;DR: In this article, a magnetostrictive wire is used to measure liquid level as a function of the elapsed time between an actuation signal and the first zero crossing of the voltage which is induced as the torsional strain passes through the area of influence of the sliding magnet.
Abstract: A liquid level detector of the type in which a magnetostrictive wire extends through the liquid level measurement range and is captured in a tensioned vertical orientation within a stainless steel tube. Liquid level is measured as a function of the time required for a torsional disturbance imparted the wire near the top to travel along the wire to a magnet which is contained within a liquid level float which slides up and down along the tube. The torsional disturbances imparted to the wire by means of a piezoelectric crystal to which the wire is easily clamped. Accuracy is enhanced by measuring liquid level as a function of the elapsed time between an actuation signal and the first zero crossing of the voltage which is induced as the torsional strain passes through the area of influence of the sliding magnet.

45 citations

Patent
08 Dec 1989
TL;DR: A magnetostrictive linear displacement detector with increased position resolution was proposed in this paper, where the displacement is determined from the interval of time between the detection of the torsional motion traveling directly from the magnet and the detection reflected from the reflection termination.
Abstract: A magnetostrictive linear displacement detector with increased position resolution includes a magnetostrictive wire anchored at opposite head and foot ends with a reflection termination at the foot end and a damping termination at the head end. A return wire is connected to the foot end of the magnetostrictive wire. The magnetostrictive wire is electrically excited at its head end. A variable position to be detected is represented by a magnet disposed for displacement along the magnetostrictive wire. A torsional motion sensor at the head end generates an electrical indication of the torsional motion within the magnetostrictive wire induced by passage of the electrical excitation by the position of the magnet. The displacement is determined from the interval of time between the detection of the torsional motion traveling directly from the magnet and the detection of the torsional motion reflected from the reflection termination. The reflection termination preferably consists of a brass cylindrical torus having a hole through which said magnetostrictive wire is passed and attached via a set screw. In an alternative embodiment the magnetostrictive wire is torsionally excited and the responses are detected electrically.

44 citations

Patent
19 Jun 1990
TL;DR: In this paper, a combined magnetostrictive linear displacement detector and a plural location temperature detector are used to produce a composite signal for transmission on a 2 wire transmission line, where the resistances of the temperature sensitive resistors as well as two reference resistors are measured in a predetermined sequence.
Abstract: The present invention is a combined magnetostrictive linear displacement detector and plural location temperature detector. The combined apparatus produces a composite signal for transmission on a 2 wire transmission line. The resistances of the temperature sensitive resistors as well as two reference resistors are measured in a predetermined sequence. The linear displacement is measured by the length of time required for a torsional strain to travel along the magnetostrictive wire to the position of the magnet. A pulse generator generates a predetermined number of pulses for each resistance measurement having pulse period corresponding to the measured resistance, with the minimum such pulse period preferably being greater than twice the maximum time required for a torsional strain to propagate the length of the magnetostrictive wire. An electrical signal is supplied to the transmission line when either said pulse generator generates a pulse or the induced electrical signal is detected. The time between the pairs of pulses indicates the linear displacement fixed by the magnet. The time between pulse pairs is a measure of one of the resistances. The combined apparatus of the present invention also periodically degausses the magneteostrictive wire at a time when no displacement measurement is taking place.

35 citations

Patent
04 Nov 1993
TL;DR: An improved magnetostrictive wire based position transducer that has applications in both liquid level measuring systems and in position indicating systems is presented in this article, where a cylindrically structured and circularly polarized piezoelectric element directly measures the torsional acoustic waves in the magnetostriction wire as they are received by the sensor.
Abstract: An improved magnetostrictive wire based position transducer that has applications in both liquid level measuring systems and in position indicating systems. A cylindrically structured and circularly polarized piezoelectric element directly measures the torsional acoustic waves in the magnetostrictive wire as they are received by the sensor. The cylindrical structure of the sensor eliminates many of the inadvertently detected acoustic and electrical pulses within the wire that are not indicative of the passage of the torsional wave of concern. The present system provides an improved sensor configuration which is selectively sensitive to torsional waves while being insensitive to vibrations in alternate planes. This improved piezoelectric sensor in combination with the electrical configuration allows placement of the magnetostrictive wire apart from the liquid whose level is being measured or from the indicator whose position is of concern. The system provides a means for transmitting the liquid level within a container to a sensor column outside of the container in a manner that improves access, maintenance, calibration, and installation. In the preferred embodiment, each of the above improvements is provided in a system that incorporates an instrumentation loop powered microprocessor based transmitter with low current requirements and increased sensitivity.

31 citations

References
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Patent
Francis V Adams1
23 Dec 1955

9 citations

Patent
03 Sep 1957
TL;DR: In this paper, two adjacent coils are arranged coaxially on the magnetostrictive member of a transducer for an acoustic delay line and are electrically connected together to generate magnetic fluxes of opposite sense; and means are provided to generate a circumferential magnetic flux in said member.
Abstract: 827,258. Acoustic delay lines. MULLARD Ltd. Sept. 3, 1957, No. 27776/57. Class 40 (8). Two adjacent coils are arranged coaxially on the magnetostrictive member of a transducer for an acoustic delay line and are electrically connected together to generate magnetic fluxes of opposite sense; and means are provided to generate a circumferential magnetic flux in said member. Coils 2 and 3 are wound in opposite senses on a wire 1 of electrically conducting magnetostrictive material e.g. nickel, and a current is passed through the wire from a battery to generate the circumferential magnetic flux. The signal to be delayed is applied to terminals 4, 5; the signal from the resultant of the circumferential and longitudinal fluxes in one sense is shown at 11, Fig. 5, and the other signal at 12 and the total resultant delayed signal is shown comparatively undistorted in Fig. 5a. Alternatively the circumferential magnetic flux may be provided by an E.M.F. applied to coils wound toroidally on coils 2, 3 and the magnetostrictive member may be in the form of a sleeve secured to the line by a resin adhesive. A receiving and a transmitting transducer are used in the delay line which is vibrated in a torsional mode.

5 citations