US1415748A - Electrical resistor - Google Patents

Description

E. WElNTRAUB.

ELECTRICAL RESISTOR.

1,415,748, 1 Patented Ma 9, 1022.

g vwcwto'a UNITED STATES.

PATENT OFFICE.

EZECI-IIEL WEINTRAUIB, OF NEW'YO-RK, N. Y.

ELECTRICAL m srsron.

To all whom it mag concern:

Be it known that I, EZECHIEL W'EINTRAU a citizen of the United States, residing at New York, in the county of New York, State of New York, have invented certain new and useful Improvements in Electrical Resistors; and I do hereby declare the following to be a full, clear, and exact description of the sistor possessing negative resistance characteristics and of such minute dimensions that small and rapid temperature changes may be accurately induced in the resistor sub stantially instantaneously, to produce unproportional changes in its electrical conductivity.

It is well known that metallic wires may be constructed with suiiicientlyminute d1- ameters,for eXample,-one to twelve microns, which, when heatedlby' a varying electric current, will follow variations in such a current with corresponding undistorted temperature variations and substantially without lag. No means, however, are known whereby minute wires maybe produced of chemical elements or materials possessing marked negative resistance characteristics and in which at the same time small and rapid temperature variations may be induced. This is particularly true of the chemical element boronvand its different ah loys, of, silicon, carboruhdum, and-similar" substances, which are most suitable because they possess marked negative resistance dhar acteristics, even at ordinary temperatures-1- The methods of. obtaining boron. and the properties ofthis element ha've been de-v scribed in United States Patents Nos,"

997,879, 019,569 and 1,074,672. I

In accordance with this invention,

negative temperature J c eificienr of; ance, and which at the'samet me' are -capae ble of following rapid 'temperatur eifiuctuations produced by a varying electrlc heating;

. current in an electrical conductor,-'orby ex ternally applied temperature variations, are

overcome by the use of a very fine filament or minute wire core coatedwith .avery th1n.;. layer of the negative resistance materialn- Such a resistor, in its completed form, will be termed a micronic'resistor, because of its Specification of Letters Patent.

Application filed April 30, 1920. I Serial No. 377,942.

which H- fillustMtion; 1

Patented May 9, 1.922.

very minute diametrical dimension, namely,

.asthe negative resistance material, the wire of mic'r'onic dimensions may be heated in an atmosphere ofa boron compound, such as boron chloride and hydrogen, as described .in United States Patent N 0. 1,019,569. The

amount of the reagents, the temperature and the time of treatment, as described in this patent, may be so regulated as to deposit an extremely thin coating of boron in intimate contact with the surface of the metallic wire core. The core and coating may be made in this way to have a total diameter of micronic dimensions, as will (be readily understood. The extremely thin boron coating so obtained may be used as. the negative resistance element in accordance with this invention. Conta'ct may be made with the coating if desired, by'fusing a fine wire orwires, into contact'with its surface.

A micronic resistor possessing negative re sistance, constructed in accordance with this inventi0n,-is readily adaptable for use in suitably associated electric circuits to am- 'plify varying'electrical currents, for example,*telephone currents,f--and other electric 90 "The'micronic resistor may be connected'in electrical circuits-so that both the minute wire core and the very thin coatingare in thesame'circuit, or ,the circuitarrangement g :{the very. thin coating maybe in separate p circuitswhich. are associated by'means of we Y viiculties of producing resistorsjpossessi-ng.

currents for signaling For other purposes.

may be such that the minute-wire core and 'the"."negativeresistance material coating. I The micronic resistor and .the mannerv 50f .ficonnectin'g the resistor in suitable electric :cireuits, as well as other objects and "ad: {vantages of theinvention, will be more. a clearly understood from,- a description of I i ,certainf preferred embodiments thereof, as [illustrated in the accompanying drawings,

.reri iz 1. "illustrates alongitudinal sectional View. oi the micronic resistor,"' -'tlie, propor-' l'tions'bei-ng-exaggerated for theifpurposes of. k

'ng only one fine wire fused into contact: vith the coating, the proportions being exaggerated, as in the case of Fig. 1, for the purposes of illustration;

Figs. 3 and 4 illustrate the use of the micronic resistor in suitable circuit arrangements for the amplification of electric currents;

Fig. illustrates the use of the micronic resistor in a series circuit connection.

Referring now to Fig. 1, the niicronic resistor 1 comprising the minute wire core 2 and the extremely thin negative resistance material coating 3, has two fine wires 4 and 5 fused into contact with the coating 3.

The fine wires etand 5 may be fused into,

contact with the coating 3 by passing an electric heating current through the core 2 and holding thefine wire, which may be of platinum, tungsten, or the like in slight contact with the coating 3 until the coating becomes heated toa point at which the afiinity of the two materials will cause an intimate contactto he made. In Fig. 1 the composite resistor 1 and the two fine wires 4 and 5 are adapted to be connected in different electric circuits, that is, the circuit containing thecore 2 would not necessarily be conductively connected other than through the negative resistance vmaterial coating to the electric circuit containing the fine Wires 1 and 5.

ing a core 7 and a negative resistance material coating 8 has only one fine wire 9 fused into. contact with the coating 8. With this arrangement of micronic resistor and wire contact, the wire core 7 may be connected both in a circuit containing the wire core 7 only, and a circuit containing the fine wire contact 9.

In the arrangement shown in Fig."3,famicronic resistor 10 of the type illustrated' a in Fig. 1, is used to amplify varying elec--.',:. tric currents in the circuit 11, 12 containing "a source 13 of electrical energy and a device" 1% for varying boththe amount of, and the frequency at which the electrical energy is utilized from the source 13. Two fine wires 15, 16, respectively, are fused into intimate contact with the negative resistance material These two wires form a part of an electrical circuit 17,

of the composite resistor 10.

18 containing a soprce of electrical energy and a receiving or indicating device 20. In

this arrangement fluctuations in the temperature of the core of the composite resistor- 10 cause corresponding temperature varia- 1- tions in the negative resistance-material and the latter, due toits negative temperature coefficient of resistance, causes large changes; in the resistance of the circuit 17 18. These large changes in resistance in thecircuit 17, j

18 serve-to vary the flow of electric current In Fig. 2 the micronic resistor 6 compris case the composite resistor 21 has its wire" core associated both with the circuit 22, 23 and thecircuit28, 24:. The wire core of the composite resistor 21 in this arrangement, is common to both the input circuit22, 23 and the output circuit 23, 24. The device 25, the source of electrical energy 26, the source of electrical energy 27 and the device 28 operate in a similar manner to the corresponding component parts of the arrangement shown in ig. 3.

Fig. 5 illustrates the application of the micronic resistor 29 to ,an electric circuit 30, 31 for the purpose of amplifying the varying electric currents therein. In this arrangement, there is included in the circuit 30, 31, the source of electrical energy 32 and a source '33 of varying electric current which it is desired to amplify. The resistance of the micronic resistor 29 decreases when the strength of the current passing between the minute wire core 34 and the fine wire contact 35 increases. In consequence of the defied current impulses may be received or indicated by means of the device 36 in any suitable manner.

I 'clairn: I 121;) An; electrical 1 resistor or im'ensions' possessing a negative An electrical resistor f-comprising an electrically conductive I core having a diam- 'e'ter of, the order of twomicrons coated with 'a'thi'n layer of material possessing a negative temperature coeflicient of resistance, the total diameter of said core and coating being of the order of three microns. l

3. An electrical resistor comprising a minute metal wire core coated with a thin layer of material possessing a negative temperature coefiicient of resistance, the total diameter of said core and coating being micronic dimensions.

4. An electrical resistor comprising a minute 'metallyvire .core coated with a thin flayer'of a compound containingiborom'the' total diameter-of saidcorean d coating being of micronic dimensions.

5.. 'An I electrical resistor comprising a minute metal wire core coated with a thin ties layer of the element boron, the total diameter of said core and coating being of micronic dimensions.

6.111 an electric current amplifier, the combination with a source of electric current variations including an electric circuit, of an electrical resistor of micronic dimensions possessing a negative of resistance associated With said circuit, and means for receiving orindicating the resulting amplifiedelectric current variations.

7. In an electric current amplifier, the

temperature coefficient.

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