Difference between revisions of "Switching Contacts"

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===<!--6.4.4-->Switching Contacts===
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===6.4.4 Switching Contacts===
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<ul>
 
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'''Effects during switching operations'''
 
  
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<div class="multiple-images">
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*'''Effects during switching operations'''
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<figure id="fig:Contact_opening_with_arc_formation_schematic">
 
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[[File:Contact opening with arc formation schematic.jpg|left|thumb|<caption>Contact opening with arc formation (schematic)</caption>]]
 
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</figure>
 
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</div>
 
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<div class="clear"></div>
 
  
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'''Influence of out-gasing from plastics'''
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Fig. 6.7 Contact opening with arc formation (schematic)
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[[File:Contact opening with arc formation schematic.jpg|right|thumb|Contact opening with arc formation (schematic)]]
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*'''Influence of out-gasing from plastics'''
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Fig. 6.9:
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Histogram of the contact
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resistance R of an electroplated K
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palladium layer (3 μm) with and
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without hard gold flash plating
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(0.2 μm) after exposure with
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different plastic materials
  
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<div class="multiple-images">
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Fig. 6.10: Contact resistance with exposure to out-gasing from plastics as a function of numbers of
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<figure id="fig:Histogram_of_the_contact_resistance_Rk">
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operations at 6 V ,100 mA: 1 Silicon containing plastic; 2 Plastics with strongly out-gasing DC
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[[File:Histogram of the contact resistance Rk.jpg|left|thumb|<caption>Histogram of the contact resistance R<sub>K</sub> of an electroplated palladium layer (3 μm) with and without hard gold flash plating (0.2 μm) after exposure with different plastic materials</caption>]]
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components; 3 Plastics with minimal out-gasing components
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</figure>
 
  
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<figure id="fig:Contact resistance with exposure to out gasing from plastics">
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*'''Influence of corrosive gases on the contact resistance'''
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[[File:Contact resistance with exposure to out gasing from plastics.jpg|left|thumb|<caption>Contact resistance with exposure to out-gasing from plastics as a function of numbers of operations at 6 V<sub>DC</sub>,100 mA: 1 Silicon containing plastic; 2 Plastics with strongly out-gasing components; 3 Plastics with minimal out-gasing components</caption>]]
 
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</figure>
 
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</div>
 
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<div class="clear"></div>
 
  
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Fig. 6.11: Distribution of cumulative frequency H of the contact resistance for solid contact rivets
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after 10 days exposure in a three-component test environment with 400 ppb each of H<sub>2</sub>S, SO<sub>2</sub> and
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NO<sub>2</sub> at 25°C, 75% RH; Contact force 10cN; Measuring parameters: ≤ 40 mV<sub>DC</sub>,10 mA; Probing
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contact: Gold rivet
  
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'''Influence of corrosive gases on the contact resistance'''
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Fig. 6.8: Influences on contact areas in relays
  
  
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<div class="multiple-images">
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*'''Contact Phenomena under the influence of arcing Matertia'''
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<figure id="fig:Distribution of cumulative frequency H of the contact resistance for solid contact rivets">
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*'''Material transfer'''
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[[File:Distribution of cumulative frequency H of the contact resistance for solid contact rivets.jpg|left|thumb|<caption>Distribution of cumulative frequency H of the contact resistance for solid contact rivets after 10 days exposure in a three-component test environment with 400 ppb each of H<sub>2</sub>S, SO<sub>2</sub> and NO<sub>2</sub> at 25°C, 75% RH; Contact force 10cN; Measuring parameters: ≤ 40 mV<sub>DC</sub>,10 mA; Probing
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Fig. 6.12: Material transfer under DC load a) Cathode; b) Anode.
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contact: Gold rivet</caption>]]
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6 Material: AgNi0.15; Switching parameters: 12VDC, 3 A, 2x10 operations
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</figure>
 
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<figure id="fig:Influences on contact areas in relays">
 
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[[File:Influences on contact areas in relays.jpg|right|thumb|<caption>Influences on contact areas in relays</caption>]]
 
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</figure>
 
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</div>
 
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<div class="clear"></div>
 
  
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*'''Arc erosion'''
  
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'''Contact Phenomena under the influence of arcing Matertia'''
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Fig. 6.13 Arc erosion of a Ag/SnO<sub>2</sub> contact pair after extreme arcing conditions
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<ul>
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a) Overall view; b) Partial detail view
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'''Material transfer'''
 
  
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<div class="multiple-images"><figure id="fig:Material transfer under DC load">[[File:Material transfer under DC load.jpg|left|thumb|<caption>Material transfer under DC load a) Cathode; b) Anode. <br /> Material: AgNi0.15; Switching parameters: 12V<sub>DC</sub>, 3 A, 2x10<sup>6</sup> perations</caption>]]</figure></div>
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*'''Contact welding'''
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<div class="clear"></div>
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Fig. 6.14: Micro structure of a welded contact pair (Ag/SnO<sub>2</sub> 88/12 - Ag/CdO88/12)  
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after extremely high current load. a) Ag/SnO<sub>2</sub> 88/12; b) Ag/CdO88/12
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'''Arc erosion'''
 
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<div class="multiple-images"><figure id="fig:Arc erosion of a AgSnO2 contact pair after extreme arcing conditions">[[File:Arc erosion of a AgSnO2 contact pair after extreme arcing conditions.jpg|left|thumb|<caption>Arc erosion of a Ag/SnO<sub>2</sub> contact pair after extreme arcing conditions a) Overall view; b) Partial detail view</caption>]]</figure></div>
 
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<div class="clear"></div>
 
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'''Contact welding'''
 
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<div class="multiple-images">
 
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<figure id="fig:Micro structure of a welded contact pair after extremely high current load">
 
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[[File:Micro structure of a welded contact pair after extremely high current load.jpg|left|thumb|<caption>Micro structure of a welded contact pair (Ag/SnO<sub>2</sub>88/12 - Ag/CdO88/12) after extremely high current load. a) Ag/SnO<sub>2</sub>88/12; b) Ag/CdO88/12</caption>]]
 
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</figure>
 
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</div>
 
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<div class="clear"></div>
 
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</ul>
 
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</ul>
 
  
 
==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]]
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[[de:Schaltende Kontakte]]
 

Revision as of 14:10, 1 April 2014

6.4.4 Switching Contacts

  • Effects during switching operations

Fig. 6.7 Contact opening with arc formation (schematic)

Contact opening with arc formation (schematic)
  • Influence of out-gasing from plastics

Fig. 6.9: Histogram of the contact resistance R of an electroplated K palladium layer (3 μm) with and without hard gold flash plating (0.2 μm) after exposure with different plastic materials

Fig. 6.10: Contact resistance with exposure to out-gasing from plastics as a function of numbers of operations at 6 V ,100 mA: 1 Silicon containing plastic; 2 Plastics with strongly out-gasing DC components; 3 Plastics with minimal out-gasing components

  • Influence of corrosive gases on the contact resistance

Fig. 6.11: Distribution of cumulative frequency H of the contact resistance for solid contact rivets after 10 days exposure in a three-component test environment with 400 ppb each of H2S, SO2 and NO2 at 25°C, 75% RH; Contact force 10cN; Measuring parameters: ≤ 40 mVDC,10 mA; Probing contact: Gold rivet

Fig. 6.8: Influences on contact areas in relays


  • Contact Phenomena under the influence of arcing Matertia
  • Material transfer

Fig. 6.12: Material transfer under DC load a) Cathode; b) Anode. 6 Material: AgNi0.15; Switching parameters: 12VDC, 3 A, 2x10 operations

  • Arc erosion

Fig. 6.13 Arc erosion of a Ag/SnO2 contact pair after extreme arcing conditions a) Overall view; b) Partial detail view

  • Contact welding

Fig. 6.14: Micro structure of a welded contact pair (Ag/SnO2 88/12 - Ag/CdO88/12) after extremely high current load. a) Ag/SnO2 88/12; b) Ag/CdO88/12

References

References

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