Difference between revisions of "Contact Physics – Formulas"
From Electrical Contacts
(→6.4.2 Contact Physics – Formulas) |
|||
| (14 intermediate revisions by 3 users not shown) | |||
| Line 1: | Line 1: | ||
| − | === | + | ===6.4.2 Contact Physics – Formulas=== |
*'''Constriction resistance''' | *'''Constriction resistance''' | ||
| Line 40: | Line 40: | ||
| − | {| class="twocolortable | + | {| class="twocolortable" style="text-align: left; font-size: 12px" |
|- | |- | ||
!Material combination | !Material combination | ||
| Line 48: | Line 48: | ||
|(0.08 bis 0.14) x 10<sup>-3</sup> | |(0.08 bis 0.14) x 10<sup>-3</sup> | ||
|- | |- | ||
| − | | | + | |Aluminium - Aluminium |
| − | | | + | |Copper and copper alloys for springs and connectors |
|- | |- | ||
| − | | | + | |DIN EN 1758 |
| − | | | + | |Copper and copper alloys in strip form for system component carriers |
|- | |- | ||
| − | | | + | |ASTM B 103/B103M-10 ||Spec. for Phosphor Bronce Plate, Sheet, Strip, and Rolled Bar |
| − | | | ||
|- | |- | ||
| − | | | + | |ASTM B 36/B36M-95 || Spec. for Brass Plate, Sheet, Strip, and Rolled Bar |
| − | | | ||
|- | |- | ||
| − | | | + | |ASTM B 122/B122M-08 || Spec. for CuNiSn-, CuNiZn-, and CuNi-Alloy |
| − | |||
| − | | | ||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
|- | |- | ||
| − | | | + | |ASTM B 465-09 || Spec. for Copper-Iron-Alloy Plate, Sheet, and Strip |
| − | | | ||
|- | |- | ||
| − | | | + | |ASTM B 194-08 || Standard Spec. for CuBe-Alloy Plate, Sheet, Strip and Rolled Bar |
| − | | | ||
|- | |- | ||
| − | | | + | |ASTM B 534-07 || Sec. for CuCoBe-Alloy and CuNiBe-Alloy Plate, Sheet, Strip, and Rolled Bar |
| − | | | ||
|- | |- | ||
| − | |||
| − | |||
| − | |||
| − | |||
| − | |||
|} | |} | ||
| − | |||
==References== | ==References== | ||
[[Application Tables and Guideline Data for Use of Electrical Contact Design#References|References]] | [[Application Tables and Guideline Data for Use of Electrical Contact Design#References|References]] | ||
| − | |||
| − | |||
Revision as of 09:58, 1 April 2014
6.4.2 Contact Physics – Formulas
- Constriction resistance
(Single spot contact according to Holm; circular touching spot between clean contact surfaces)
(Multi-spot contact according to Holm without influence between the N individual spots)
(Multi-spot contact according to Greenwood considering the influence between the spots)
- Contact resistance
- Path resistance
- Contact resistance and contact force
![R_K = 280\rho \sqrt[3]{E (F_K \cdot r)}](/matheasy/bda0b56c91fccaa4c9a75816e15c1815.svg)
(According to Holm model for film-free spherical contact surfaces with plastic deformation of the contact material; Fk < 1 N for typical contact materials)
(According to Holm model for film-free spherical contact surfaces with plastic deformation of the contact material; Fk > 5 N for typical contact materials)
- Dynamic contact separation (without considering magnetic fields caused by the current path)
(Rule of thumb with FA in N and l in kA)
- Contact voltage and max. contact temperature
- Contact resistance at higher contact forces (according to Babikow)
For FK between 10 and 200 N
c = material dependent proportionality factor
m = shape dependent exponent of the contact force
| Material combination | c |
|---|---|
| Copper - Copper | (0.08 bis 0.14) x 10-3 |
| Aluminium - Aluminium | Copper and copper alloys for springs and connectors |
| DIN EN 1758 | Copper and copper alloys in strip form for system component carriers |
| ASTM B 103/B103M-10 | Spec. for Phosphor Bronce Plate, Sheet, Strip, and Rolled Bar |
| ASTM B 36/B36M-95 | Spec. for Brass Plate, Sheet, Strip, and Rolled Bar |
| ASTM B 122/B122M-08 | Spec. for CuNiSn-, CuNiZn-, and CuNi-Alloy |
| ASTM B 465-09 | Spec. for Copper-Iron-Alloy Plate, Sheet, and Strip |
| ASTM B 194-08 | Standard Spec. for CuBe-Alloy Plate, Sheet, Strip and Rolled Bar |
| ASTM B 534-07 | Sec. for CuCoBe-Alloy and CuNiBe-Alloy Plate, Sheet, Strip, and Rolled Bar |
