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
  • H01C7/10—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 voltage responsive, i.e. varistors
  • H01C7/105—Varistor cores
  • H01C7/108—Metal oxide
  • H01C7/112—ZnO type

Definitions

• MeO is an oxide selected from the oxides of magnesium, calcium, strontium, barium, iron, cobalt, lead, boron, aluminum, bismuth, manganese, chr0- mium, nickel, antimony, and mixtures thereof. An improved method of manufacturing such a resistance material is also described.
• the invention relates to a resistance material wherein the resistance varies exponentially with the voltage drop and, more particularly, relates to a sintered ceterminal wires (pigtails) can be attached.
• invention also relates to a method of manufacturing such material.
• Such resistance materials are well known and have been made from, for example, silicon carbide, titanium dioxide or zinc oxide.
• the voltage drop across elements made from such materials is given by the following equation:
• n is, therefore, a direct measure of the magnitude of non-linearity based on p-n-transitions, on the contact among the individual grains, or on the material itself.
• the B-value of a non-linear resistance element may be varied by sintering at varying temperatures and under different atmospheres. It is further known to adjust the B-value through the thickness of the resistance elements. Both procedures permit only a limited possibility of variation. Thus, when there is a change in temperature the desired n-value, in many cases, is not attained and when there is a change in thickness, desired small increments of resistance often are not attainable.
• the first object is particularly advantageously solved by a composition
• a composition comprising about 50-90% ZnO, about 0.1 40% ZnF and about 0.1 40% MeO; wherein MeO is an oxide selected from the oxides of magnesium, calcium, strontium, barium, iron, cobalt, lead, boron, aluminum, bismuth, manganese, chromium, nickel, antimony, and mixtures thereof.
• the B-value of the material may be varied within wide ranges by changing the ratio of the two components ZnO and ZnF,. If, meanwhile, the metal oxide content is kept unchanged, the n-value of the material remains nearly constant. However the nvalue can be adjusted to many values by varying the MeO content.
• composition adapted for use as an electrical resistance element wherein the electrical resistance varies exponentially with the voltage drop across the elementksaigl vp ltage drop being given by the equation:
• E is said voltage drop
• I is the current through the element
• B is a constant equal to the voltagevalue at which the current is equal to l Ampere
• n is a number
• said composition comprising about 50-90% ZnO, about 0.1 40% ZnF and about 0.1 40% MeO; wherein MeO is an oxide selected from the oxides of magnesium, calcium, strontium, barium, iron, cobalt, lead, boron, aluminum, bismuth, manganese, chromium, nickel, antimony, and mixtures thereof.
• composition according to claim 1 in which the ZnF proportion is about l8% and the MeO content is about 246%.
• composition according to claim 1 wherein said MeO is approximately equal molar proportions of Bizoa, C030, Mnoz, and Sb203.
• composition according to claim 2 wherein said MeO is approximately equal molar proportions of Bigoa, C0304, M1102, and sbgoa.
• composition according to claim 1 wherein said composition is in the form of a resistance element.
• the method of manufacturing a composition adaptable for use as an electrical resistance element comprises the steps of a. forming a homogeneous mixture of about 50-90% ZnO, about 0.1 40% ZnF and about 0.1 40% MeO wherein MeO is an oxide selected from the oxides of magnesium, calcium, strontium, barium, iron, cobalt, lead, boron, aluminum, bismuth, manganese, chronium, nickel, antimony, and mixtures thereof;
• MeO is approximately equal molar proportions of Blzoa, C0304, Mnoz, and Sb203.

Landscapes

• Engineering & Computer Science (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Compositions Of Oxide Ceramics (AREA)
• Thermistors And Varistors (AREA)
• Investigating Or Analyzing Materials By The Use Of Fluid Adsorption Or Reactions (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=5887280

Family Applications (1)

Country Status (7)

Cited By (7)

Citations (2)

• 1974
  • 1974-07-15 IT IT25169/74A patent/IT1017155B/it active
  • 1974-07-15 GB GB3123374A patent/GB1461116A/en not_active Expired
  • 1974-07-16 IE IE1507/74A patent/IE39620B1/xx unknown
  • 1974-07-16 US US489182A patent/US3925261A/en not_active Expired - Lifetime
  • 1974-07-17 SE SE7409336A patent/SE395788B/xx unknown
  • 1974-07-17 FR FR7424835A patent/FR2237860B1/fr not_active Expired
  • 1974-07-18 NL NL7409767A patent/NL7409767A/xx not_active Application Discontinuation

Patent Citations (2)

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