Difference between revisions of "General Rules for Dimensioning of Contacts"

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(6.4.6 General Rules for Dimensioning of Contacts)
 
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===6.4.6 General Rules for Dimensioning of Contacts===
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===<!--6.4.6-->General Rules for Dimensioning of Contacts===
  
*'''Recommended Minimum Contact Forces at Slightly Sliding Contact Make:'''
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'''Recommended Minimum Contact Forces at Slightly Sliding Contact Make:'''
  
{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
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<table class="twocolortable" style="text-align: left; font-size: 12px;width:40%">
|-
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<tr>
|Gold       
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<td>Gold</td>      
|0.03 N
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<td>0.03 N </td>
|-
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</tr><tr>
|Silver  
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<td>Silver </td>
|0.1 N
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<td>0.1 N</td>
|-
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</tr><tr>
|Tungsten   
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<td>Tungsten  </td>
|0.5 N
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<td>0.5 N</td>
|-
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</tr>
|}
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</table>
  
*'''Contact Force Recommendations:'''
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'''Contact Force Recommendations:'''
  
 
{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
 
{| class="twocolortable" style="text-align: left; font-size: 12px;width:40%"
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*'''General Rules for Dimensioning of Contact Rivets'''
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'''General Rules for Dimensioning of Contact Rivets'''
  
[[File:General Rules for Dimensioning of Contact Rivets.jpg|left|thumb|General Rules for Dimensioning of Contact Rivets]]
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[[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%"
 
{| class="twocolortable" style="text-align: left; font-size: 12px;width:100%"
 
|-
 
|-
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|&#8776; 0.3 mm
 
|&#8776; 0.3 mm
 
|}
 
|}
*'''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. 6.18: Failure probability of a contact as a
+
'''Failure Probability of Single and Double (Bifurcated) Contacts''' (according to Thielecke)
function of the voltage (according to Kirchdorfer);
+
 
Ag/Ni10; 10 mA
+
{| 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>
 +
|-
 +
|0.3
 +
|5.5 x 10<sup>-6</sup>
 +
|1.5 x 10<sup>-6</sup>
 +
|1.8 x 10<sup>-7</sup>
 +
|3.2 x 10<sup>-10</sup>
 +
|}
 +
 
 +
 
 +
<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.jpg|left|thumb|Figure 2: Failure probability of a contact as a function of the voltage (according to Kirchdorfer); Ag/Ni10; 10 mA]]
 +
</figure>
  
Fig. 6.19: Failure probability of a contact as a
+
<figure id="fig:Failure probability of a contact as a function of the current">
function of the current (according to
+
[[File:Failure probability of a contact as a function of the current.jpg|left|thumb|Figure 3: Failure probability of a contact as a function of the current (according to Kirchdorfer); Ag/Ni10; F<sub>k</sub> = 0.45 N; U = 24 V]]
Kirchdorfer); Ag/Ni10; F = 0.45 N; U = 24 V
+
</figure>
 +
</div>
 +
<div class="clear"></div>
  
 
==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]]
 +
 +
[[de:Faustregeln_für_die_Kontaktdimensionierung]]

Latest revision as of 13:01, 26 January 2023

General Rules for Dimensioning of Contacts

Recommended Minimum Contact Forces at Slightly Sliding Contact Make:

Gold 0.03 N
Silver 0.1 N
Tungsten 0.5 N

Contact Force Recommendations:

Signal relays ≥ 3 cN
AC power relays ≥ 20 cN
Automotive relays ≥ 20 cN
Motor switches (Contactors)
(Silver – Metal oxide contacts)
0.05 - 0.08 N/A
Power switches 0.1 - 0.2 N/A
Connectors
(Gold coating)
≥ 30 cN/contact element
Connectors
(Silver coating)
≥ 50 cN/contact element
Connectors
(Tin coating)
≥ 1 N/contact element


General Rules for Dimensioning of Contact Rivets

Figure 1: General Rules for Dimensioning of Contact Rivets
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
smin ≈ 0.3 mm



Failure Probability of Single and Double (Bifurcated) Contacts (according to Thielecke)

Contact force[N] Single contact
Ag AuNi 5, Pt Ag AuNi 5, Pt
0.04 1 x 10-4 2 x 10-8
0.1 2 x 10-3 4 x 10-5 8 x 10-5 8 x 10-9
0.2 1 x 10-4 8 x 10-6 4 x 10-6 4 x 10-8
0.3 5.5 x 10-6 1.5 x 10-6 1.8 x 10-7 3.2 x 10-10


Figure 2: Failure probability of a contact as a function of the voltage (according to Kirchdorfer); Ag/Ni10; 10 mA
Figure 3: Failure probability of a contact as a function of the current (according to Kirchdorfer); Ag/Ni10; Fk = 0.45 N; U = 24 V

References

References