SE190812C1

SE190812C1 -

Info

Publication number: SE190812C1
Authority: SE
Publication date: 1964-01-01

Description

Uppfinnare: G G Scarrott Prioritet begard fran den 11 november 1955 (Storbritannien) Den .foreliggande uppfinningen avser en analogiomvandlare for avgivande av en elektrisk signal med en frekvens, som .ar proportionell mot en variabel mekanisk kraft, me-deist en raknare, som raknar antalet signalcykler under en viss tidsperiol, kan signalen bringas att ange storleken av kraften. Inventor: GG Scarrott Priority Required from 11 November 1955 (Great Britain) The present invention relates to an analog converter for emitting an electrical signal having a frequency which is proportional to a variable mechanical force, by means of a razor which rakes the number signal cycles during a certain period of time, the signal can be made to indicate the magnitude of the force.

Kraften kan erhallas frail en tryckkapsel for att angiva trycket av en vatska, gas eller anga; den kan aven erhallas fran en bimetallroma for att angiva temperatur, Andra tilllampningar av ■uppfinningen aro emellertid mojliga. The power can be obtained from a pressure capsule to indicate the pressure of a liquid, gas or steam; it can also be obtained from a bimetallic roma to indicate temperature. However, other embodiments of the invention are possible.

Ett andamal med uppfinningen ar att astadkomma en analogiomvandlare for det angivna andamalet, som ar enkel till sin konstruktion men andock ger exakta resuiltat. An object of the invention is to provide an analog converter for the stated object, which is simple in its construction but still gives exact results.

Analogiomvandlaren enligt uppfinningen bestar av tva bOjfiga, langstrackta elektriska ledare med samma ,massa per langdenhet och med i huvudsak samma vibrerande langd, en langdanordning for att halla ledarna under mekanisk dragspanning i langdriktningen, en drivanordning for att bibringa ledarnas namnda ilangder en transversell vibrationsrorelse, en anordning, t. ex. ett havstangssystem for att i linjart beroende av kraften bibringa ledarna olika dragspanningar pa sa satt, att dragspannin.gen i den ena ledaren okas och samtidigt dragspanningen i den andra ledaren minskasimyeket, raknat .fran ett tillstand, i vilket dragspanningen fir densamma i hada ledarna nar kraften ar noll, samt en mordning for att avgiva den elektriska signalen med en frekvens, sum Or lika med skillnaden mellan ledarnas vibrationsfrekvenser. The analog converter according to the invention consists of two flexible, elongate electrical conductors with the same mass per unit length and with substantially the same vibrating length, a length device for holding the conductors under mechanical tensile stress in the longitudinal direction, a drive device for imparting a transverse vibration movement to said conductors. device, e.g. a sea rod system for imparting different tensile stresses in a linear manner depending on the force in such a way that the tensile stress in one conductor is increased and at the same time the tensile stress in the other conductor is reduced, from a state in which the tensile stress for the same conductors reaches the force is zero, as well as a murder to emit the electrical signal with a frequency, sum Or equal to the difference between the vibration frequencies of the conductors.

Med >i huvudsak lika langden menas att langderna Oro lika med undantag av de mycket sma avvikelser, som uppkomma genom de olika dragspanningarna i ledarna. By> substantially equal length is meant that the lengths Oro equal with the exception of the very small deviations, which arise due to the different tensile stresses in the conductors.

For att bibringa ledarna transversell svangningsrorelse kan for varje ledare finnas ett Dupl. kl. 42 k: 12/05; 74 b: 8/08 magnetiskt falt, som flr transversellt riktat i farhallande till ledarens vibrationsriktning, samt vidare en elektrisk krets med effektivt negativt motstand, i vilken ledaren ingar. Vid detta utfarande kan i anordningen fOr uttag,- ning av signalen inga ett blandarsteg for alstring av en elektrisk spanning med en frekvens, som fir lika med skillnaden mellan frekvenserna for strommarna i kretsarna. To impart transverse oscillation motion to the conductors, there may be a Dupl for each conductor. at 42 k: 12/05; 74 b: 8/08 magnetic field, which is transversely directed in relation to the direction of vibration of the conductor, and furthermore an electrical circuit with effective negative resistance, in which the conductor engages. In this method, in the device for extracting the signal, there can be no mixer stage for generating an electrical voltage with a frequency which is equal to the difference between the frequencies of the currents in the circuits.

Pa. den bifogade ritningen visas i vy fran sidan oeh schematiskt ett utforande av en analogiom.vandlare enligt uppfinningen. iMed 11 och 12 betecknas tva langstrackta ledare med samma massa per langdenhet och med gamma langd i icke-spant tillstand. Ledarna aro utforda av ett starkt, ieke-magnetiskt, korrosionsbestandigt material, som aven utgor en for andamalet tillrackligt god elektrisk ledare, exempelvis berylliumkoppar. Ledarna ha formen av mycket tunna remsor (pa ritningen sedda mot kanten och med overdriven tjocklek), vilka aro anordnade parallellt med varandra med den ena anden (den hOgra I figuren) infast och elektriskt isolerad. De motsatta andarna aro fasta vid de hada andarna av en. .dubbelarmad havstang 13, som vid sin mitt vilar mot en knivegg 14, vilken app-bares i en punkt mellan de hada andarna av en annan havstang 15. Den ena anden av hay- s-Lai-igen 15 Or widbart anbragtett fast un- derlag vid 16; en stark dragfjader 17 verkar pa havstangens andra ande i sadan riktning, att ledarna 11, 12 hallas sparida. Den variahla kraften 18 verkar pa havstangen 13 Over en arm 19, som stracker sig frail havstangen 13 i sadan riktning, att kraften stravar att rotera havstangen 13 omkring kniveggen 14. Pa. the accompanying drawing is shown in side view and schematically an embodiment of an analog converter according to the invention. 11 and 12 denote two elongate conductors with the same mass per unit length and with gamma length in the non-spanned state. The conductors are challenged by a strong, non-magnetic, corrosion-resistant material, which also constitutes a sufficiently good electrical conductor for the spirit, for example beryllium copper. The conductors are in the form of very thin strips (seen in the drawing towards the edge and with excessive thickness), which are arranged parallel to each other with one end (the one on the right in the figure) fixed and electrically insulated. The opposite spirits are attached to the hated spirits of one. double-armed sea rod 13, which at its center rests against a knife wall 14, which is app-bared at a point between the hated spirits of another sea rod 15. One spirit of hay-s-Lai-weer 15 derlag at 16; a strong tension spring 17 acts on the other spirit of the sea rod in such a direction that the conductors 11, 12 are kept sparse. The varying force 18 acts on the sea rod 13 over an arm 19 which extends from the sea rod 13 in such a direction that the force tends to rotate the sea rod 13 around the knife wall 14.

Ledarna aro anbragta i ett fast falt 20 med riktning i vinkel, lampligen rat vinkel, mot den riktning, 1 vtlken ledarna skola vibrera. Den senare riktningen Or vinkelrat mot remsornas plan; pa ritningen visas faltet sasom 2— — bildande rat vinkel med papperets plan. Fordelningen av faltet utmed vardera ledarens langd Or lampligen sinusformig. Ledarens 11 andar aro elektriskt forbundna med ett steg 21, som med ledaren bildar en krets med effektivt negativt motstand. En lamplig anordning Or ett rorsteg med ledaren ingaend.e i ingangskretsen och anordnat fiir positiv aterkappling. lindarna av ledaren 12 Oro pa liknande satt forbundna med ett liknande steg 22. Stegen 21 och 22 Oro fOrbundna med ett blandarsteg 23, som är anordnat .att over ett uttag 24 avge en elektrisk signalspanning vid en frekvens, som utgor skillnaden mellan frekvenserna for strommarna i ledarna 11, 12. The conductors are arranged in a fixed field 20 with a direction at an angle, suitably at an right angle, to the direction in which the conductors are to vibrate. The latter direction Or perpendicular to the plane of the strips; the drawing shows the field as 2 - - forming a right angle with the plane of the paper. The distribution of the field along the length of each conductor Or is suitably sinusoidal. The spirits of the conductor 11 are electrically connected to a stage 21, which with the conductor forms a circuit with effective negative resistance. A lamp device Or a rudder stage with the conductor ending in the input circuit and arranged for positive feedback. The coils of the conductor 12 are similarly connected to a similar stage 22. Steps 21 and 22 are connected to a mixer stage 23, which is arranged to emit an electrical signal voltage across a terminal 24 at a frequency which is the difference between the frequencies of the currents. in leaders 11, 12.

Genam samverkan mellan det magnetiska faltet och kretsarna med negativt motstand hallas ledarna 11, 12 i transversell resonant vibration vinkelratt mot ledarnas plan med en frekvens, som for vardera ledaren 1 ett givet ogonblick beror enbart pa ledarens vibrerande langd, dess massa per langdenhet och den dragspanning, som den for agonblicket fir underkastad. Vardera kretsen med negativt motstand verkar som en oscillator, och den erhallna strommen liar sanuna frekvens, som den, .med villten iledaren vibrerar. Through the interaction between the magnetic field and the negative resistance circuits, the conductors 11, 12 are held in transverse resonant vibration perpendicular to the plane of the conductors at a frequency which for each conductor 1 at a given moment depends solely on the vibrating length of the conductor, its mass per unit length and the tensile voltage , as it for the agonblick fir subjected. Each circuit with negative resistance acts as an oscillator, and the obtained current has the same frequency as that which the wild conductor vibrates.

Den dragspanning, sam vardera ledaren ar underkastad, hestammes av dragfjadern 17 och kraften 18. Anordningen Or sadan, att nat. kraften 18 Or lika med noll ger fjadern 17 IAda ledarna samma dragspanning. DO de vibrerande langderna Oro lika Or var roch en av de tre ovannamnda faktorerna, som bestamma resonansvibrationsfrekvensen for en av ledarna, lika med motsvarande faktor f Or den andra ledaren. De tva. ledarna vibrera .darfor med samma frekvens, och Oven de oscillerande strommarna ha samma frekvens. Frekvensen for utgangssignalen Over uttaget 24 Or dad& lika med noll. The tensile stress to which each conductor is subjected is driven by the tensile spring 17 and the force 18. The device Or so that nat. force 18 Or equal to zero, the spring 17 IAda gives the conductors the same tensile voltage. DO the vibrating lengths Oro equal to Or were roch one of the three factors mentioned above, which determine the resonant vibration frequency of one of the conductors, equal to the corresponding factor f Or the other conductor. It was. the conductors vibrate .therefor the same frequency, and above the oscillating currents have the same frequency. The frequency of the output signal Over the socket 24 Or dad & equal to zero.

Nar kraften 18 ej Or lika .med noll kommer den att Oka dragspanningen i ledaren 12, under forutsattning att den verkar i den av pilen angivna riktningen, och aninskar dragspanningen i ledaren 11 lika mycket. Da dragspanningarna nu Oro olika Oro vibrationsfrekvenserna ej langre lika. Det kan visas att skilinaden mellan dessa frekvenser Or mycket nara praportionell mot storleken av kraften 18. Den signalspanning, som erhalles Iran blandarsteget 23 Over uttaget 24, liar dad& en frekvens, som Or proportionell mot kraften 18. When the force 18 is not equal to zero, it will increase the tensile stress in the conductor 12, provided that it acts in the direction indicated by the arrow, and increases the tensile stress in the conductor 11 by the same amount. Since the tensile stresses now Oro different Oro vibration frequencies are no longer the same. It can be shown that the difference between these frequencies is very closely proportional to the magnitude of the force 18. The signal voltage obtained in Iran mixer stage 23 across the terminal 24 is equal to a frequency which is proportional to the force 18.

Nar heist kraften 18 har ett annat varde an noll bli dragspanningarnalolika i de bath ledarna och dessa ha darfor ej langre exakt samma langd. Denna avvikelse Or emellertid sit liten, aft man kan bortse Iran densamma. When heist force 18 has a different value to zero, the tensile stresses become similar in the bath conductors and these therefore no longer have exactly the same length. This deviation, however, is small, since Iran can be ignored.

Fjadern 17 .maste vara tillrackligt stark i forhallande till kraften 18 for att Italia den ledare under dragspanning, vans dragspanning minskas gerrom verkan av kraften 18. The spring 17 must be sufficiently strong in relation to the force 18 for the conductor under tensile stress, the tensile stress of which is reduced by the effect of the force 18.

Sa.som redan namnts kan kraften 18 erhallas fran en tryckkapsel for att angiva trycket av en vatska, gas eller anga, eller frau en bimetallremsa far att angiva temperatur. Kraften kan givetvis Oven erhallas pa manga andra satt, beroende pa arten av den storhet som skall maths. As already mentioned, the force 18 can be obtained from a pressure capsule to indicate the pressure of a liquid, gas or steam, or from a bimetallic strip to indicate temperature. The power can of course also be obtained in many other ways, depending on the nature of the quantity to be fed.

Den signal, som erhalles Over uttaget 24 kan Over en tidmatare tillforas en raknare, sa att ett matt pa frekvensen erhalles genom rakning av antalet cykler under en tidsperiod, som bestanunes av tiduret. The signal received via the terminal 24 can be applied to a timer via a timer, so that a measurement of the frequency is obtained by counting the number of cycles during a period of time, which is determined by the timer.

Claims

Patent claim:

An analogue converter for emitting an electrical signal with a frequency, which Or is proportional to a variable mechanical force, characterized by partly two flexible, elongated electric declarers (11, 12) with the same mass per unit length and with essentially the same vibrating length, partly a longitudinal device (13 - 17) for holding the conductors under mechanical tensile stress in the longitudinal direction, partly a drive device (20, 21, 22) for imparting a transverse vibration movement to the said lengths of the conductors, partly a device (13, 11, 19), t ex. a sea rod system, in order to impart different tensile stresses in line On depending on the force text, in such a way that the tensile stress in one conductor is equalized in the same man as the tensile stress in the other conductor is reduced as much, Iran found a condition in which the tensile stress Or the same in had the conductors reach the force of zero, and on the other hand a device (23) is allowed to emit the electrical signal with a frequency equal to Or equal to the difference between the vibration frequencies of the conductors.

Device according to claim 1, characterized in that the device (20, 21, 22) is allowed to impart a transverse oscillating movement to the conductors (11, 12) for each conductor generates a magnetic field (20) at a right angle to the direction of vibration of the conductor and contains electrical circuits (21 and 22, respectively), which in turn each contain their negative resistance and their respective conductors.

Device according to claim 2, characterized in that the device (23) outputs the signal contains a mixing stage for generating an electrical voltage with a frequency which is equal to. the difference between the frequencies of the currents in the named circuits (21, 22). Request publications: ATM-Archiv für technisches Messen 1932: sept. sheet V 132-1.