US2651699A - Thermosensitive resistance element - Google Patents

Thermosensitive resistance element Download PDF

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Publication number
US2651699A
US2651699A US268224A US26822452A US2651699A US 2651699 A US2651699 A US 2651699A US 268224 A US268224 A US 268224A US 26822452 A US26822452 A US 26822452A US 2651699 A US2651699 A US 2651699A
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US
United States
Prior art keywords
thermistor
bead
resistance element
wires
thermosensitive resistance
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US268224A
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English (en)
Inventor
Jacobsen Bent Bulow
Daly Charles Trevor
Thomas David Lane
Wolfson Henry
Shepard Stanley Carden
Green David
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
International Standard Electric Corp
Original Assignee
International Standard Electric Corp
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Filing date
Publication date
Application filed by International Standard Electric Corp filed Critical International Standard Electric Corp
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Publication of US2651699A publication Critical patent/US2651699A/en
Anticipated expiration legal-status Critical
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01C—RESISTORS
    • H01C7/00—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material
    • H01C7/04—Non-adjustable resistors formed as one or more layers or coatings; Non-adjustable resistors made from powdered conducting material or powdered semi-conducting material with or without insulating material having negative temperature coefficient

Definitions

  • THERMOSENSITIVE RESISTANCE ELEMENT Sept. 8, 1953 illlliliillla J Filed Jan. 25, 1952 l/V VEN TO R5 5. 5. JACOBSE/V C- T. DALY a 1.. THOMAS H. WOL F5 0M 5 C. SHEPARD a GREEN A ttnrne y Patented Sept. 8,
  • THERMOSENSITIVE RESISTANCE ELEMENT Bent Bulow J acobsen, Charles Trevor Daly, David Lane Thomas, Henry Wolfson, Stanley Garden Shepard, and David Green, London, England, assignors to International Standard Electric Corporation, New York, N. Y.
  • the present invention relates to electric thermo-sensitive resistance elements of the kind known as thermistors.
  • thermistors are in automatic gain control arrangements employed in communication systems, in which the thermistor forms part of the gain control network associated with an amplifier, and the heating of the thermistor is controlled by a pilot current transmitted with the communication signals.
  • the thermistor should have a high thermal capacity, and low heat losses.
  • the object of the present invention is to improve the design of thermistors so that they meet these requirements more closely.
  • an indirectly heated thermistor comprising in an evacuated envelope, a thermistor body consisting of a bead of thermosensitive resistance material having a pair of terminal leads, and enclosed in a heating coil of such length as also to enclose a section of each of the said leads and terminal wires for the said heating coil, each of which wires is coiled in such manner as to provide a choke for reducing the rate of conduction of heat along the said wire.
  • the thermistor comprises a small bead l of suitable thermosensitive resistive material having embedded therein two fine Wires 2 and 3 serving as the terminal leads for the bead. These wires are soldered or otherwise conductively attached respectively to a pair of lead-out conductors 4 and 5 of heavier gauge.
  • the thermistor bead l is embedded at the centre of a cylinder 6 of electrically non-conducting cement carrying on its outside surface a helical heater winding I wound closely to the bead l.
  • the assembly is slipped inside a thin cylindrical metal tube 8, preferably of silver.
  • the assembly consisting of the elements l, 6, l and 8 will be called, for convenience, the thermistor body.
  • terminal leads 9 and In for the heater winding '1 are wound into coils for the purpose of acting as heat conduction chokes. These terminal leads are soldered, or otherwise conductively attached respectively to two lead-out conductors II and I2 of heavier gauge which also act as supports for the thermistor.
  • the whole assembly is mounted in the usual way in an evacuated envelope (not shown).
  • the principal feature of the invention is the use of the coiled terminal leads 9, It for the heater winding by which the rate of conduction of heat along these leads is reduced, so that there will be a small temperature gradient between the thermistor body and its supports.
  • Another feature is bringing out both the bead conductor wires, 2, 3 through the same end of the heater winding, and increasing the length of this winding so that it overlaps a considerable length of these wires, as shown in the figure, whereby there will be no temperature gradients in the bead, and the loss oi heat by conduction along these Wires will also be reduced.
  • the metal tube 8 should have a polished outer surface to reduce heat radiation, the preferred metal bein silver, as already stated. This tube increases the thermal capacity of the thermistor, and the dimensions should be chosen so that by its presence a greater increase in thermal capacity than in the heat losses is produced.
  • the use of a metal enclosure for the thermistor is known, and is described in British patent specification No. 555,563.
  • the terminal leads 2 and 3 for the thermistor bead should be made from the smallest gauge wire which is practicable, and the material of this wire should preferably be a metal or alloy which has the highest possible ratio or" the thermal to the electrical resistance. This feature is also disclosed in the above-mentioned patent specification.
  • a further desirable point is that the diameter of the non-conducting cylinder 6 should be as small as possible in order to have the minimum possible clearance between the heating winding i and the bead l.
  • the envelope (not shown) in which the thermistor is enclosed should be evacuated as highly as possible.
  • An indirectly heated thermistor comprising, in an evacuated envelope, a thermistor body consisting of a bead of thermosensitive resistance material, a pair of terminal leads extending parallel to each other in the same direction from one end of the bead, a heating coil enclosing said thermistor body and of such length as to enclose a section of said leads, and terminal wires for the said heating coil, each of which Wires is coiled in such manner as to provide a choke for reducwire'.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Resistance Heating (AREA)
  • Thermistors And Varistors (AREA)
US268224A 1951-01-30 1952-01-25 Thermosensitive resistance element Expired - Lifetime US2651699A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB2298/51A GB675730A (en) 1951-01-30 1951-01-30 Improvements in or relating to thermosensitive resistance elements

Publications (1)

Publication Number Publication Date
US2651699A true US2651699A (en) 1953-09-08

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ID=9737098

Family Applications (1)

Application Number Title Priority Date Filing Date
US268224A Expired - Lifetime US2651699A (en) 1951-01-30 1952-01-25 Thermosensitive resistance element

Country Status (4)

Country Link
US (1) US2651699A (de)
BE (1) BE508830A (de)
CH (1) CH299854A (de)
GB (1) GB675730A (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2926299A (en) * 1954-04-21 1960-02-23 Mcdermott Controls Inc Electrical instrument with thermistor sensing element
US3387115A (en) * 1965-10-14 1968-06-04 Owens Coring Fiberglas Corp Programming apparatus

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE942300C (de) * 1952-03-24 1956-05-03 Csf Waermeempfindliches Element und Verfahren zur Herstellung eines waermeempfindlichen Elementes
US3505632A (en) * 1966-12-09 1970-04-07 Fujitsu Ltd Indirectly heated thermistor
US3697863A (en) * 1971-01-04 1972-10-10 Texas Instruments Inc Overcurrent protection system and sensor used therewith

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB555563A (en) * 1941-08-30 1943-08-27 Standard Telephones Cables Ltd Electric resistor devices
US2396196A (en) * 1943-05-15 1946-03-05 Bell Telephone Labor Inc Controllable resistor
FR931661A (fr) * 1945-07-30 1948-03-01 Philips Nv Résistance à coefficient de température négatif

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB555563A (en) * 1941-08-30 1943-08-27 Standard Telephones Cables Ltd Electric resistor devices
US2396196A (en) * 1943-05-15 1946-03-05 Bell Telephone Labor Inc Controllable resistor
FR931661A (fr) * 1945-07-30 1948-03-01 Philips Nv Résistance à coefficient de température négatif

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2926299A (en) * 1954-04-21 1960-02-23 Mcdermott Controls Inc Electrical instrument with thermistor sensing element
US3387115A (en) * 1965-10-14 1968-06-04 Owens Coring Fiberglas Corp Programming apparatus

Also Published As

Publication number Publication date
GB675730A (en) 1952-07-16
BE508830A (de) 1953-07-17
CH299854A (de) 1954-06-30

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