Difference between revisions of "Switching Contacts"
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− | === | + | ===6.4.4 Switching Contacts=== |
<ul> | <ul> | ||
− | '''Effects during switching operations''' | + | <li>'''Effects during switching operations'''</li> |
+ | |||
+ | <xr id="fig:fig6.7"/> Fig. 6.7: Contact opening with arc formation schematic | ||
<div class="multiple-images"> | <div class="multiple-images"> | ||
− | <figure id="fig: | + | <figure id="fig:fig6.7"> |
[[File:Contact opening with arc formation schematic.jpg|left|thumb|<caption>Contact opening with arc formation (schematic)</caption>]] | [[File:Contact opening with arc formation schematic.jpg|left|thumb|<caption>Contact opening with arc formation (schematic)</caption>]] | ||
</figure> | </figure> | ||
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<div class="clear"></div> | <div class="clear"></div> | ||
− | '''Influence of out-gasing from plastics''' | + | <li>'''Influence of out-gasing from plastics'''</li> |
+ | |||
+ | <xr id="fig:fig6.9"/> Fig. 6.9: Histogram of the contact resistance Rk of an electroplated palladium layer (3 μm) with and without hard gold flash plating (0.2 μm) after exposure with different plastic materials | ||
+ | |||
+ | <xr id="fig:fig6.10"/> Fig. 6.10: 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 | ||
+ | |||
<div class="multiple-images"> | <div class="multiple-images"> | ||
− | <figure id="fig: | + | <figure id="fig:fig6.9"> |
[[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>]] | [[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>]] | ||
</figure> | </figure> | ||
− | <figure id="fig: | + | <figure id="fig:fig6.10"> |
[[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>]] | [[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>]] | ||
</figure> | </figure> | ||
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− | '''Influence of corrosive gases on the contact resistance''' | + | <li>'''Influence of corrosive gases on the contact resistance'''</li> |
+ | <xr id="fig:fig6.11"/> 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 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 | ||
+ | contact: Gold rivet | ||
<div class="multiple-images"> | <div class="multiple-images"> | ||
− | <figure id="fig: | + | <figure id="fig:fig6.11"> |
[[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 | [[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 | ||
contact: Gold rivet</caption>]] | contact: Gold rivet</caption>]] | ||
− | |||
− | |||
− | |||
</figure> | </figure> | ||
</div> | </div> | ||
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− | '''Contact Phenomena under the influence of arcing Matertia''' | + | Fig. 6.8: Influences on contact areas in relays |
+ | |||
+ | |||
+ | <li>'''Contact Phenomena under the influence of arcing Matertia'''</li> | ||
<ul> | <ul> | ||
− | '''Material transfer''' | + | <li>'''Material transfer'''</li> |
− | <div class="multiple-images"><figure id="fig: | + | <xr id="fig:fig6.12"/> Fig. 6.12: 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> operations |
+ | |||
+ | <div class="multiple-images"><figure id="fig:fig6.12">[[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> | ||
<div class="clear"></div> | <div class="clear"></div> | ||
− | '''Arc erosion''' | + | <li>'''Arc erosion'''</li> |
− | <div class="multiple-images"><figure id="fig: | + | <xr id="fig:fig6.13"/> Fig. 6.13: Arc erosion of a Ag/SnO<sub>2</sub> contact pair after extreme arcing conditions a) Overall view; b) Partial detail view |
+ | |||
+ | <div class="multiple-images"><figure id="fig:fig6.13">[[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> | ||
<div class="clear"></div> | <div class="clear"></div> | ||
− | '''Contact welding''' | + | <li>'''Contact welding'''</li> |
+ | |||
+ | <xr id="fig:fig6.14"/> Fig. 6.14: 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 | ||
<div class="multiple-images"> | <div class="multiple-images"> | ||
− | <figure id="fig: | + | <figure id="fig:fig6.14"> |
[[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>]] | [[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>]] | ||
</figure> | </figure> | ||
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==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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Revision as of 16:12, 1 April 2014
6.4.4 Switching Contacts
- Effects during switching operations
- Influence of out-gasing from plastics
- Influence of corrosive gases on the contact resistance
- Contact Phenomena under the influence of arcing Matertia
- Material transfer
- Arc erosion
- Contact welding
Figure 1 Fig. 6.7: Contact opening with arc formation schematic
Figure 2 Fig. 6.9: Histogram of the contact resistance Rk of an electroplated palladium layer (3 μm) with and without hard gold flash plating (0.2 μm) after exposure with different plastic materials
Figure 3 Fig. 6.10: Contact resistance with exposure to out gasing from plastics as a function of numbers of operations at 6 VDC,100 mA: 1 Silicon containing plastic; 2 Plastics with strongly out-gasing components; 3 Plastics with minimal out-gasing components
Figure 4 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
Figure 5 Fig. 6.12: Material transfer under DC load a) Cathode; b) Anode.
Material: AgNi0.15; Switching parameters: 12VDC, 3 A, 2x106 operations
Figure 6 Fig. 6.13: Arc erosion of a Ag/SnO2 contact pair after extreme arcing conditions a) Overall view; b) Partial detail view
Figure 7 Fig. 6.14: Micro structure of a welded contact pair (Ag/SnO288/12 - Ag/CdO88/12) after extremely high current load. a) Ag/SnO288/12; b) Ag/CdO88/12