Difference between revisions of "Contact Physics – Formulas"

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===<!--6.4.2-->Contact Physics – Formulas===
+
{|
 
+
|'''Editor''':
*'''Constriction resistance'''  
+
|DODUCO Holding GmbH<br>
: $R_e = \rho/2a$
+
Im Altgefäll 12<br>
(Single spot contact according to Holm; circular touching spot between clean
+
75181 Pforzheim / Germany<br>
contact surfaces)
+
Phone +49 (0) 7231 602-0<br>
: $R_e = \rho/2Na$
+
Fax +49 (0) 7231 602-398<br>
(Multi-spot contact according to Holm without influence between the N
+
Mail: info@doduco.net<br>
individual spots)
 
: $R_e = \rho/2 x \sum a_i + 3 \pi \rho /32N^2 x \sum \sum (s_ij) i \neq j$
 
(Multi-spot contact according to Greenwood considering the influence between
 
the spots)
 
 
 
*'''Contact resistance'''
 
: $R_K = R_e + R_f$
 
 
 
*'''Path resistance'''
 
: $R_d = R_b + R_K$
 
 
 
*'''Contact resistance and contact force'''
 
: $R_K = 280\rho \sqrt[3]{E (F_K \cdot r)} $
 
(According to Holm model for film-free spherical contact surfaces with plastic
 
deformation of the contact material; F<sub>k</sub> < 1 N for typical contact materials)
 
: $R_K = 9000 \rho \sqrt{ H/ F_K}$
 
(According to Holm model for film-free spherical contact surfaces with plastic
 
deformation of the contact material; F<sub>k</sub> > 5 N for typical contact materials)
 
 
 
*'''Dynamic contact separation''' (without considering magnetic fields caused by the current path)  
 
: $F_A \approx 0,8 xl^2$
 
(Rule of thumb with F<sub>A</sub> in N and l in kA)
 
 
 
*'''Contact voltage and max. contact temperature'''
 
: $T_kmax \approx 3200 U_K$
 
 
 
*'''Contact resistance at higher contact forces (according to Babikow)'''
 
: $R_K = cF_k^{-m}$
 
For F<sub>K</sub> between 10 and 200 N<br/>
 
c = material dependent proportionality factor<br/>
 
m = shape dependent exponent of the contact force
 
 
 
 
 
{| class="twocolortable scalable" style="text-align: left; font-size: 12px; width:45%;"
 
 
|-
 
|-
!Material combination
+
|'''Managing Directors''':
!c
+
|
 +
Dr. Hans-Joachim Dittloff (Vorsitzender)<br>
 +
Dr. Franz Kaspar<br>
 +
Hajo Kufahl<br>
 
|-
 
|-
|Copper - Copper
+
|'''Registration''':
|(0.08 bis 0.14) x 10<sup>-3</sup>
+
|HRB 710592 AG Mannheim
 
|-
 
|-
|Aluminum - Aluminum
+
|'''Consulting and Realisation''':
|(3 bis 6,7) x 10<sup>-3</sup>
+
|Steinbeis - Transferzentrum Unternehmensentwicklung an der Hochschule Pforzheim (SZUE)<br>
 +
Blücherstraße 32 <br>
 +
75177 Pforzheim <br>
 +
https://www.szue.de/
 
|-
 
|-
|Brass - Brass
+
|'''Revision and German version''':
|0.67 x 10<sup>-3</sup>
+
|Christian Teitscheid - Teitscheid Freelance IT<br>
 +
Barbarastraße 22 <br>
 +
47495 Rheinberg <br>
 +
http://www.teitscheid-freelance.de/
 
|-
 
|-
|Steel – Silver
 
|0.06 x 10<sup>-3</sup>
 
|-
 
|Steel – Copper
 
|3.1 x 10<sup>-3</sup>
 
|-
 
|Steel – Brass
 
|3.0 x 10<sup>-3</sup>
 
|}
 
 
{| class="twocolortable scalable" style="text-align: left; font-size: 12px; width:45%; "
 
|-
 
!Contact shapes
 
!m
 
|-
 
|Flat – Flat
 
|1
 
|-
 
|Pyramid – Flat
 
|0.5
 
|-
 
|Sphere – Flat
 
|0.6
 
|-
 
|Sphere – Sphere
 
|0.5
 
|-
 
|Multi-strand brush - Flat
 
|1
 
|-
 
|Current bar (Busbar) contact
 
|0.5 - 0.7
 
 
|}
 
|}
<div class="clear"></div>
 
 
==References==
 
[[Application Tables and Guideline Data for Use of Electrical Contact Design#References|References]]
 
 
[[de:Formeln_aus_der_Kontaktphysik]]
 

Revision as of 14:16, 25 January 2017

Editor: DODUCO Holding GmbH

Im Altgefäll 12
75181 Pforzheim / Germany
Phone +49 (0) 7231 602-0
Fax +49 (0) 7231 602-398
Mail: info@doduco.net

Managing Directors:

Dr. Hans-Joachim Dittloff (Vorsitzender)
Dr. Franz Kaspar
Hajo Kufahl

Registration: HRB 710592 AG Mannheim
Consulting and Realisation: Steinbeis - Transferzentrum Unternehmensentwicklung an der Hochschule Pforzheim (SZUE)

Blücherstraße 32
75177 Pforzheim
https://www.szue.de/

Revision and German version: Christian Teitscheid - Teitscheid Freelance IT

Barbarastraße 22
47495 Rheinberg
http://www.teitscheid-freelance.de/