SE123712C1

SE123712C1 -

Info

Publication number: SE123712C1
Authority: SE
Publication date: 1948-01-01

Description

KLASS 21 c:54/01 BESKRIVNING OFFENTLIGGJORD AV KUNGL. CLASS 21 c: 54/01 DESCRIPTION PUBLISHED BY KUNGL.

PATENT- OCH REGISTRERINGSVERKET Ans. den1946, nr 6691/1946. PATENT AND REGISTRATION AGENCY Ans. den1946, No. 6691/1946.

BEVIIJAT DEN 4 NOVEMBER 1948 PATENTTID FRAN DEN 27 JUL! 1946 PUBLICERAT DEN 4 JANUAR! 1949 Milli11 en ritning. GRANTED ON NOVEMBER 4, 1948 PATENT PERIOD FROM JULY 27! 1946 PUBLISHED ON JANUARY 4! 1949 Milli11 a drawing.

N. V. PHILIPS' GLOEILAAIPENFABRIEKEN, EINDHOVEN, NEDERLANDERNA. Motstand med negativ temperaturkoefficient. N. V. PHILIPS 'GLOEAAIPENFABRIEKEN, EINDHOVEN, NEDERLANDERNA. Resistance with negative temperature coefficient.

Uppfhmare: E. J. W. Verwey. Author: E. J. W. Verwey.

Prioritet begiird frdn den 30 juli 1945 (Nederlanderna). Priority requested from 30 July 1945 (Netherlands).

FOreliggande uppfinning avser ett motstand med negativ temperaturkoefficient, vid vilket motstandskroppen, som har i huvudsak cylindrisk form, är anbragt i ett roc av exempelvis keramiskt material och dr elektriskt forbunden med anslutningskontakter vid liiidarna av roret eller i Mirheten darav medelst ledare, vilka ha stort motstand mot den termiska stromningen frail motstandskroppen till anslutningskontakterna. The present invention relates to a resistor with a negative temperature coefficient, in which the resistor body, which has a substantially cylindrical shape, is arranged in a rock of, for example, ceramic material and electrically connected to connection contacts at the conductors of the tube or in the vicinity thereof by conductors which have high resistance. against the thermal flow frail the resistor body to the connection contacts.

Vid anvandning av .motstand med negativ temperaturkoefficient fir det ofta Onskvart, sdrskilt nar sadana motstand anvandas i kopplingsanordningar, i vilka de skola astadkomma en begransning av inkopplingsstromimpulsen, att den vanligen .cylindriska motstandskroppen ãr termiskt isolerad sa val som mojligt. Harigenom uppnas, att motstandskroppens sluttemperatur blir sa hog som mojligt och foljaktligen motstandets slutliga motstandsvarde och den i detsamma forbrukade energien bli de minsta mojliga. When using a resistor with a negative temperature coefficient, it is often uncommon, especially when such resistors are used in switching devices, in which they are to provide a limitation of the switching current pulse, that the usually cylindrical resistor body is thermally insulated as far as possible. In this way it is achieved that the final temperature of the resistance body becomes as high as possible and consequently the final resistance value of the resistance and the energy consumed in it become the smallest possible.

Det är redan kant att anbringa mot:standskroppen i ett ror av glas eller keramik ()eh upphanga den dari medelst tunna tradar, vilka samtidigt tjana som elektriska tillforingsledare. Ett sadant motstand beskrives exempelvis i det amerikanska patentet 2 017 011. Denna konstruktion dr emellertid jamforelsevis dyrbar och skrymmande. Vidare har uppbdrandet av motstfindskroppen endast medelst tillforingsledarna den olagenheten, att dessa ledare med nodvandighet maste vara tillrackligt starka for att icke sd latt brytas solider som foljd av mekaniska stiitar eller vibrationer, fOr vilka motstandet kan utsattas, under det att a andra sidan ett stort termiskt mot-stand has ledarna är onskvart, ett forhallande, som kan uppnas genom reducering av ledarens diameter. It is already edge to apply to: the stand body in a tube of glass or ceramic () eh hang it there by means of thin wires, which at the same time serve as electrical supply conductors. Such resistance is described, for example, in U.S. Patent 2,017,011. However, this construction is comparatively expensive and bulky. Furthermore, the support of the resistor body only by means of the supply conductors has the disadvantage that these conductors must necessarily be strong enough so as not to break solidly as a result of mechanical struts or vibrations to which the resistor may be subjected, while on the other hand a large thermal The resistance of the conductors is uneven, a ratio which can be achieved by reducing the diameter of the conductor.

Andamalet med uppfinningen ar att astadkomma en enkel konstruktion, som icke drager med sig dessa olagenheter och som lam-par sig att pa enkelt salt tillverkas billigt genom masstillverkningsmetoder. The object of the invention is to provide a simple construction which does not entail these disadvantages and which lamps itself to be manufactured cheaply on simple salt by mass production methods.

Enligt uppfinningen ar en av rorets och motstandstroppens cylindriska ytor, vilka dro vanda mot varandra, forsedd med atminsione tre ribbliknande utsprang for uppbarande av motstfindskroppen, -vilka ribbor stracka sig i en riktning i huvudsak parallell med rorets axel och uppvisa ett stort motstand mot den termiska stromning, som passerar genom ribborna fran motstandskroppen till roret. Ribborna kunna anordnas pa rorets inre vagg och bilda en del darav, eller ocksa kan motstandskroppen spiv vara fOrsedd med ribbliknande utsprang. Pd sa satt erhalles en bilhg konstruktion med liten storlek och med en form, som dr lamplig for montering i radiomottagare eller liknande apparater, varvid det icke desto mindre är mojligt att erhalla tillracklig varmeisolering for att hdlla motstandskroppens temperatur hog och tempera Wren hos motstandets yttre yta sa lag, att i fall av kontakt med andra delar dessa icke kunna skadas. According to the invention, one of the cylindrical surfaces of the rudder and the resistance strap, which draw water towards each other, is provided with at least three rib-like projections for supporting the resistance body, which ribs extend in a direction substantially parallel to the axis of the rudder and have a large resistance to the thermal flow, which passes through the ribs from the resistor body to the rudder. The ribs can be arranged on the inner wall of the tube and form part of it, or the resistor body can also be provided with rib-like projections. In this way a small construction is obtained with a small size and with a shape which is suitable for mounting in radio receivers or similar devices, whereby it is nevertheless possible to obtain sufficient thermal insulation to keep the temperature of the resistor body high and the temperature of the outer surface of the resistor. said law, that in case of contact with other parts these can not be damaged.

Uppfinningen fortydligas som exempel med hjalp av bifogade ritning, pa vilken fig. 1 ar en vy i axialsektion av en utfbringsform, medan fig. 2 är en vy i tvarsektion efter linjen II—II i fig. 1. The invention is illustrated by way of example with the aid of the accompanying drawing, in which Fig. 1 is a view in axial section of an embodiment, while Fig. 2 is a cross-sectional view along the line II-II in Fig. 1.

Det i fig. 1 och 2 visade motstandet bestar av ett ror 1 av keramiskt material, som vid andarna Or forsett med tva anslutningskontakter i form av rnetallhu-var 3, sena aro fastklamda ph roret. Inuti roret ar anbragt en stavliknande motstandskropp 5 av for andamalet lampligt motstandsmaterial med negativ temperaturkoefficient, exempelvis en blandning av magnesiumoxid och titanoxid. Far att motstandskroppen skall ga fri frau rorets 1 innervagg ar den senare forsedd med Ire eggformade ribbon 7, som aro parallella med r8rets axe!. Motstandskroppen 5 vilar pa. tva av de Ire ribborna 7 och halles pa sin plats axiell riktning av tva skruvfjadrar 9, vilka samtidigt bilda anslutningsledarna till anslutningskontakterna 3. The resistor shown in Figs. 1 and 2 consists of a tube 1 of ceramic material, which at the spirits Or is provided with two connection contacts in the form of metal number caps 3, which are later clamped to the tube. Arranged inside the tube is a rod-like resistance body 5 of the resilient material with a negative temperature coefficient, for example a mixture of magnesium oxide and titanium oxide. In order for the resistance body to be free from the inner cradle of the tube 1, the latter is provided with inner edge-shaped ribs 7, which are parallel to the axis of the tube !. The resistance body 5 rests on. two of the inner ribs 7 and are held in place in the axial direction by two helical springs 9, which simultaneously form the connecting conductors of the connecting contacts 3.

Tack vane forekomsten av ribborna 7 halles motstandskroppen 5 pa avstand Iran rorets 1 inre vagg, sa att den termiska kontakten mel- 2— — Ian dessa delar kan direkt forsigga endast genom luften i raret. Endr ribborna am smala och yidare eggformade foreligger endast en liten direkt kontaktyta mellan riiret och motstandskroppen, sa att aven lungs denna bana ringa yarmeaverforing kan Aga rum. Den tredje yagen for den termiska stramningen, d. v. s. genom skruyfjadrarna, erbjuder likaledes ett ayseyart motstand mot denna strOmning, enfir fjadrarna, ehuru de aro av metall, ha ringa diameter och betydande langd. Tack vare dessa atgarder gar den beskrivna konstruktionen det mOjligt att erhalla en termisk isolering av motstandskroppen, som är mycket fordelaktig med hansyn till motstandets ringa starlek och att motstandet vidare Or tillfredsstallande skyddat mot mekanisk averkan. Vid en praktisk utfOringsform var rorets diameter 6 mm och dess langd 10. mm. Motstandet Or mycket lampligt for montering i radiomottagare och liknande apparater. For delta andamai kunna kontakthuvarna pa vaniigt shit farses med anslutningstradar 11. Due to the habit of the presence of the ribs 7, the resistance body 5 is kept at a distance from the inner wall of the pipe 1, so that the thermal contact between these parts can be made directly only through the air in the tube. Although the ribs are narrow and more ovoid, there is only a small direct contact area between the tube and the resistance body, so that even this path has little yarm transfer. The third ya for the thermal tightening, i.e. through the coil springs, likewise offers a yyseyart resistance to this flow, enfir the springs, although they are of metal, have small diameter and considerable length. Thanks to these measures, the construction described makes it possible to obtain a thermal insulation of the resistor body, which is very advantageous in view of the small strength of the resistor and that the resistor is furthermore satisfactorily protected against mechanical action. In a practical embodiment, the tube diameter was 6 mm and its length 10. mm. The resistor Or very suitable for mounting in radio receivers and similar devices. For delta andamai, the contact heads on ordinary shit can be stuffed with connecting lines 11.

Anvandningen av skruvspiralformiga fjadrar for den elektriska forbindelsen mellan undhuyarna ay ett car och ett i detta ror inneslutet motstand har redan beskriyits i del tyska patentet 530 475 och Mg& icke flagon del av uppfinningen. Fjadrarna 9 kunna ersattas ay raka tradar, som, tack vare att motstandskroppen 5 uppbiires av ribborna 7, kunna ha mycket liten diameter och pa sa sutt ha hogt motstand mot den termiska strainningen frau motstandskroppen till kontakter.na3. &Isom torde framga av det foregaende, kan det beskrivna motstemdet utforas med ringa kostnad. Anordningen ay de uppbarande elementen for motstandskroppen Or sadan, att raret liksom motstandskroppen sjaly latt kunna framstUllas i en extrusionspress. The use of helical springs for the electrical connection between the housings of a car and a resistor enclosed therein has already been described in part German patent 530 475 and Mg & non-flake part of the invention. The springs 9 can be replaced by straight wires, which, thanks to the resistance body 5 being supported by the ribs 7, can have a very small diameter and thus have high resistance to the thermal straining from the resistance body to the contacts. & As is apparent from the foregoing, the described contradiction can be carried out at little cost. The device ay the supporting elements for the resistance body Or such that the tube as well as the resistance body can easily be produced in an extrusion press.

Vid den oyan beskrivna utforingsformen av uppfinningen utgara ribborna 7 mat riktade utsprang pa rarets innervagg, men uppfinningen kan likavihl tillampas genom att motstandskroppen forses med pa avstand fran varandra anbragta ribbor. In the embodiment of the invention described above, the ribs 7 are food-directed projections on the inner wall of the tube, but the invention can nevertheless be applied by providing the resistance body with ribs arranged at a distance from each other.

Claims

Claim: A resistor with a negative temperature coefficient, in which the resistor body, which has a substantially cylindrical shape, is arranged in a tube of, for example, ceramic material and electrically connected to connection contacts at the spirits in the tube or in the vicinity by conductors against the thermal flow from the resistor body to the connecting contacts, characterized in that one of the cylindrical surfaces of the rod and the resistor body, which face each other, is provided with at least three rib-like projections for supporting the resistor body, which ribs extend in a parallel direction substantially axis of the rudder and have a large resistance to the thermal flow which passes through the ribs from the resistance body to the rudder. Stockholm 1948. Kungl. Boktr. P. A.Norstedt & Si5ner 480089