===<!--6.4.6 -->General Rules for Dimensioning of Contacts===
*'''Recommended Minimum Contact Forces at Slightly Sliding Contact Make:'''
<table class="twocolortable" style="text-align: left; font-size: 12px;width:40%"><tr><td>Gold</td> <td>0.03 N </td></tr><tr><td>Silver </td><td>0.1 N</td></tr><tr><td>Tungsten </td><td>0.5 N</td></tr></table> '''Contact Force Recommendations:''' {| class="twocolortable" style="text-align: left; font-size: 12px;width:3040%"|-|Signal relays |≥ 3 cN|-|AC power relays |≥ 20 cN|-|Automotive relays |≥ 20 cN|-|Motor switches (Contactors)<br />(Silver – Metal oxide contacts)|0.05 - 0.08 N/A
|-
|Gold Power switches |0.03 1 - 0.2 N/A
|-
|Silver Connectors<br />(Gold coating)|0.1 N≥ 30 cN/contact element
|-
|Tungsten Connectors<br />(Silver coating)|0.5 N≥ 50 cN/contact element
|-
|Connectors<br />(Tin coating)
|≥ 1 N/contact element
|}
*'''Contact Force Recommendations:'''
Signal relays >3 cNAC power relays > 20 cNAutomotive relays > 20 cNMotor switches (Contactors) 0.05 - 0.08 N/A(Silver – Metal oxide contacts)Power switches 0.1 - 0.2 N/AConnectors > 30 cN/contact element(Gold coating)Connectors > 50 cN/contact element(Silver coating)Connectors > 1 N/contact element(Tin coating)'''General Rules for Dimensioning of Contact Rivets'''
*'''[[File:General Rules for Dimensioning of Contact Rivets'''.jpg|left|thumb|Figure 1: General Rules for Dimensioning of Contact Rivets]]{| class="twocolortable" style="text-align: left; font-size: 12px;width:100%"|-!Dimensioning!Solid Rivets (1)!Composite Rivets (2)|-|a : d |1.5 : 1 bis 2.5 : 1|2 : 1 bis 2.5 : 1 |-|a : b |2.5 : 1 bis 10 : 1|3 : 1 bis 5 : 1|-|c : b |≥ 1 : 1|≥ 1 : 1|-|b : s ||≥ 2 : 1|-|s<sub>min</sub> ||≈ 0.3 mmbild|}
*'''Head diameter for electrical loads'''
For AC currents: approx. 1 – 1.5 A/mm²
For 1 A min. 2 mm head diameter
10 A approx. 3 – 3.5 mm head diameter
20 A approx. 5 mm head diameter
For DC currents: approx. 0.5 – 0.8 A/mm²
*'''Head radius R for electrical loads'''
for I < 1 A R 1,5 mm
I = 6 A R 5 mm
I = 10 A R 10 mm
I = 20 A R 15 mm
*'''Failure Probability of Single and Double (Bifurcated) Contacts''' (according to Thielecke)
Fig{| class="twocolortable" style="text-align: left; font-size: 12px;width:100%"|-!Contact force[N] !colspan="4" style="text-align:center"|'''Single contact'''|-! !Ag!AuNi 5, Pt!Ag!AuNi 5, Pt|-|0.04 ||1 x 10<sup>-4</sup>||2 x 10<sup>-8</sup>|-|0.1 |2 x 10<sup>-3</sup>|4 x 10<sup>-5</sup>|8 x 10<sup>-5</sup>|8 x 10<sup>-9</sup>|-|0. 2|1 x 10<sup>-4</sup>|8 x 10<sup>-6</sup>|4 x 10<sup>-6</sup>|4 x 10<sup>-8</sup>|-|0.18: Failure probability of a contact as a3|5.5 x 10<sup>-6</sup>function of the voltage (according to Kirchdorfer);|1.5 x 10<sup>-6</sup>Ag|1.8 x 10<sup>-7</Ni10; sup>|3.2 x 10<sup>-10 mA</sup>|}
Fig<div class="multiple-images"><figure id="fig:Failure probability of a contact as a function of the voitage">[[File:Failure probability of a contact as a function of the voitage. 6jpg|left|thumb|Figure 2: Failure probability of a contact as a function of the voltage (according to Kirchdorfer); Ag/Ni10; 10 mA]]</figure> <figure id="fig:Failure probability of a contact as a function of the current">[[File:Failure probability of a contact as a function of the current.19jpg|left|thumb|Figure 3: Failure probability of a contact as afunction of the current (according toKirchdorfer); Ag/Ni10; F <sub>k</sub> = 0.45 N; U = 24 V]]</figure></div><div class="clear"></div>
==References==
[[Application Tables and Guideline Data for Use of Electrical Contact Design#References|References]]
[[de:Faustregeln_für_die_Kontaktdimensionierung]]
