Switching Contacts

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Switching Contacts

  • Effects during switching operations
  • Figure 1 Contact opening with arc formation schematic

    Figure 1: Contact opening with arc formation (schematic)
  • Influence of out-gasing from plastics
  • Figure 2 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 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 2: 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: 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


  • Influence of corrosive gases on the contact resistance
  • Figure 4 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

    Figure 4: 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


    Influences on contact areas in relays
  • Contact Phenomena under the influence of arcing Matertia
    • Material transfer
    • Figure 5 Material transfer under DC load a) Cathode; b) Anode.
      Material: AgNi0.15; Switching parameters: 12VDC, 3 A, 2x106 operations

      Figure 5: Material transfer under DC load a) Cathode; b) Anode.
      Material: AgNi0.15; Switching parameters: 12VDC, 3 A, 2x106 perations
    • Arc erosion
    • Figure 6 Arc erosion of a Ag/SnO2 contact pair after extreme arcing conditions a) Overall view; b) Partial detail view

      Figure 6: Arc erosion of a Ag/SnO2 contact pair after extreme arcing conditions a) Overall view; b) Partial detail view
    • Contact welding
    • Figure 7 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

      Figure 7: 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

References

References