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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)
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− | : $R_e = \rho/2 x \sum a_i + 3 \pi \rho /32N^2 x \sum \sum (s_ij) i \neq j$
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− | (Multi-spot contact according to Greenwood considering the influence between
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− | the spots)
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− | | |
− | *'''Contact resistance'''
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− | : $R_K = R_e + R_f$
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− | | |
− | *'''Path resistance'''
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− | : $R_d = R_b + R_K$
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− | | |
− | *'''Contact resistance and contact force'''
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− | : $R_K = 280\rho \sqrt[3]{E (F_K \cdot r)} $
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− | (According to Holm model for film-free spherical contact surfaces with plastic
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− | deformation of the contact material; F<sub>k</sub> < 1 N for typical contact materials)
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− | : $R_K = 9000 \rho \sqrt{ H/ F_K}$
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− | (According to Holm model for film-free spherical contact surfaces with plastic
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− | deformation of the contact material; F<sub>k</sub> > 5 N for typical contact materials)
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− | | |
− | *'''Dynamic contact separation''' (without considering magnetic fields caused by the current path)
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− | : $F_A \approx 0,8 xl^2$
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− | (Rule of thumb with F<sub>A</sub> in N and l in kA)
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− | | |
− | *'''Contact voltage and max. contact temperature'''
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− | : $T_kmax \approx 3200 U_K$
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− | | |
− | *'''Contact resistance at higher contact forces (according to Babikow)'''
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− | : $R_K = cF_k^{-m}$
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− | For F<sub>K</sub> between 10 and 200 N<br/>
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− | c = material dependent proportionality factor<br/>
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− | m = shape dependent exponent of the contact force
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− | | |
− | | |
− | {| 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
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− | |0.06 x 10<sup>-3</sup>
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− | |-
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− | |Steel – Copper
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− | |3.1 x 10<sup>-3</sup>
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− | |-
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− | |Steel – Brass
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− | |3.0 x 10<sup>-3</sup>
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− | |}
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− |
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− | {| class="twocolortable scalable" style="text-align: left; font-size: 12px; width:45%; "
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− | |-
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− | !Contact shapes
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− | !m
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− | |-
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− | |Flat – Flat
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− | |1
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− | |-
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− | |Pyramid – Flat
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− | |0.5
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− | |-
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− | |Sphere – Flat
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− | |0.6
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− | |-
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− | |Sphere – Sphere
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− | |0.5
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− | |-
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− | |Multi-strand brush - Flat
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− | |1
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− | |-
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− | |Current bar (Busbar) contact
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− | |0.5 - 0.7
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| |} | | |} |
− | <div class="clear"></div>
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− |
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− | ==References==
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− | [[Application Tables and Guideline Data for Use of Electrical Contact Design#References|References]]
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− |
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− | [[de:Formeln_aus_der_Kontaktphysik]]
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