Classifications

• • 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
  • H01C7/042—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 mainly consisting of inorganic non-metallic substances
  • H01C7/043—Oxides or oxidic compounds
  • H01C7/046—Iron oxides or ferrites
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
  • H01B1/06—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances
  • H01B1/08—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of other non-metallic substances oxides
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01C—RESISTORS
  • H01C17/00—Apparatus or processes specially adapted for manufacturing resistors
  • H01C17/30—Apparatus or processes specially adapted for manufacturing resistors adapted for baking
• • 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
  • H01C7/001—Mass resistors

Definitions

• this result may be obtained in that a metal compound comprising a metal ion which may occur in more than one valency is heated jointly with a metal compound of the same metalloid but comprising a metal ion having a valency ditiering from that of the first metal ion so as to produce mixed crystals in the lattice of which the metal ions of the substance added occupy lattice positions of the other metal ions and a number of the latter correspondingly change their valency.
• it is pos- 2,735,824 Patented Feb. 21, 1956 sible to obtain a nickel oxide lattice comprising simultaneously bivalent and trivalent nickel the open positions of which have been filled up by incorporating lithium ions. This may be carried out, for example, by heating NiO with LiCOs in a suitable mixing ratio.
• semi-conductive material on the basis of iron oxide is obtained by heating a mixture consisting of the oxide of trivalent iron and an oxide of a metal of different valency which, upon heating with the oxide of bivalent iron, may result in a compound yielding a homogeneous mixed crystal with the oxide of trivalent iron.
• the compounds to be admixed with the iron oxide particular mention may be made of TiOz, ZrOz and SnOz in a quantity chosen in accordance with the desired number of bivalent iron ions in the final product, which is determinative of the resistance properties.
• the procedure adopted may be, for example, as follows:
• the desired specific resistance and temperature coefiicient may be accurately adustjed by a proper choice of the amount of the compound liable to the forming of the bivalent iron in addition to the trivalent iron.
• this may lead to practical difiiculties since the very small quantities then to be used cannot in a simple manner be distributed entirely homogeneously in the iron oxide.
• the resistance properties may be varied in addition by the admixture of non-conductive oxides which, together with FezOa, yield mixed crystals such as CrzOs. If in the mixture according to the above-mentioned example 15 mol. percent of F 20 are substituted by CrzOs and the mass is Worked up in a similar manner, the resistance value with equal proportioning of the resistances is 20,000 ohms at 20 C., 6-560 ohms at 50 C. and 1030 ohms at 120 C.
• the resistance properties can, however, also be varied by adding to the initial mixture an insulating material such as a ceramic, for example, bentonite, which results in the formation of a second phase. If, for example, an amount of by weight of bentonite is added to the above-mentioned mixture consisting of 99 mol. percent of FezOs and 1 mol. percent of T and this mixture is worked up in a similar manner as mentioned above, one obtains resistances having a value of 60,000
• the resistances of the non-conductive material according to the invention are suitable, for example, for eliminating voltage pulses, compensation of the temperature coefficient of metal-wire resistances and measurements of temperature.
• a resistor having a given value of specific resistance consisting essentially of substantially homogeneous mixed crystals produced by heating a mixture of about 99 mol. percent of ferric oxide and about 1 mo percent of titanium dioxide in air at a temperature of about 1200" C.

Landscapes

• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Manufacturing & Machinery (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Conductive Materials (AREA)
• Apparatuses And Processes For Manufacturing Resistors (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=32389623

Family Applications (1)

Country Status (4)

Cited By (5)

Citations (5)

• 1947
  • 1947-01-08 NL NL129683A patent/NL78887C/xx active
  • 1947-12-19 US US79285047 patent/US2735824A/en not_active Expired - Lifetime
• 1948
  • 1948-01-05 GB GB318/48A patent/GB649985A/en not_active Expired
  • 1948-01-06 BE BE479373D patent/BE479373A/xx unknown

Patent Citations (5)

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