Difference between revisions of "Switching Contacts"
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| − | === | + | ===6.4.4 Switching Contacts=== |
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| − | + | *'''Effects during switching operations''' | |
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| − | + | <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>]] | |
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| − | [[File:Contact | ||
</figure> | </figure> | ||
</div> | </div> | ||
<div class="clear"></div> | <div class="clear"></div> | ||
| + | *'''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 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 | + | contact: Gold rivet |
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| + | Fig. 6.8: Influences on contact areas in relays | ||
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| − | + | *'''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''' | + | *'''Arc erosion''' |
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| − | + | 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 | ||
| − | + | *'''Contact welding''' | |
| − | + | 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 | |
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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 13:15, 1 April 2014
6.4.4 Switching Contacts
- Effects during switching operations
Figure 1 Fig. 6.7: 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
