US4086559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electric resistor based on silicon carbide having a negative temperature coefficient
Assignee: US Philips Corp
•
Filing: 1975-09-22
•
Granted: 1978-04-25
•
Expires: 1995-09-22
Abstract
Abstract An electric resistor having a negative temperature coefficient of the electrical resistance whose resistance body consists of p-type doped pyrolytic polycrystalline cubic silicon carbide.
Inventors
- 👤 Wilhelmus Franciscus Knippenberg
- 👤 Gerrit Verspui
- 👤 Siegfried Hendrik Hagen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:51
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/04; H01C7/042; H01C7/048
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
16 words
An electric resistor having a resistance body consisting of p-type doped pyrolytic polycrystalline cubic silicon carbide.
Claim 2
Dependent Claim
16 words
An electric resistor having a resistance body consisting of p-type doped pyrolytic polycrystalline cubic silicon carbide.
Claim 3
Dependent Claim
23 words
As an electric resistor of claim 1 a support coated with a resistance body consisting of p-type doped pyrolytic polycrystalline cubic silicon carbide.
Claim 4
Dependent Claim
8 words
An N.T.C. resistor as defined by claim 1.
Claim 5
Dependent Claim
16 words
An electric resistor as claimed in claim 2, characterized in that the support is a wire.
Claim 6
Dependent Claim
30 words
An electric resistor as claimed in claim 4, characterized in that the support is conducting and consists of an element selected from the group consisting of tungsten, carbon and molybdenum.
Claim 7
Dependent Claim
29 words
An electric resistor as claimed in claim 1 , characterized wherein an element selected from the group consisting of baron and aluminium is present as a p-type doping element.
Claim 8
Dependent Claim
34 words
An electric resistor as claimed in claim 5, characterized in that at least two parallel supports separated by a coating of p-type doped pyrolytic polycrystalline cubic silicon carbide are present in a resistance body.
Claim 9
Dependent Claim
22 words
An electric resistor as claimed in claim 7, characterized in that at least one of the conducting supports serves as an electrode.
References Cited (Backward Citations)
US3157541A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-04-24 | 1981-10-24 | 1982-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-24 | 1985-10-24 | 1986-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-24 | 1989-10-24 | 1990-04-25 | $7700.00 | Window Closed / Lapsed |