Changes

==<!--6.1 --> Application Ranges for Switching Contacts==

===<!--6.1.1 -->Low and Medium Electrical Loads===Switching processes at low and medium electrical loads are experienced for example in relays and switches for the measuring technology, telecommunications, automotive usage, and appliances. The switching voltage ranges from μV to 400V with currents between μA and about 100A.

===<!--6.1.2 -->High Electrical Loads===At With high electric electrical loads that , as usually occur occuring in power engineering devices equipment, the switching phenomena are mostly related usually due to arc formationarcing. For most applications the management of the switching arc is the key problem. Depending on the device type , different require-ments requirements are dominant , which influence the selection of the contact material. Similar to those in communications engineering, issues related to the switching characteristics and current path have to be considered.

==<!--6.2 -->Contact Materials and Design of Contact Components==The highest reliability and electrical life of electromechanical components and switching devices can only be achieved if both, the material selection and the design of the actual contact parts, are optimized. Economic Of course, economic considerations must of course also be applied when selecting the most suitable contact material and its way of application as an electrical contact. In the following <xr id="tab:Material Selection and Contact Component Design"/><!--Table 6.1 --> recommendations are made for selected application examples for contact materials and contact shape or configuration.

<figtable id="tab:Material Selection and Contact Component Design"><caption>'''<!--Table 6.1: -->Material Selection and Contact Component Design''' </caption>

|Brushes from flat rolled wire or stamped; collector hard gold electroplated or clad, or ; made from miniature profile segments

 Table 1: '''Table 6.1: Material Selection and Contact Component Design (Fortsetzung)'''

<xr id="tab:Material Selection and Contact Component Design"/><!--Table 6.1 --> is meant to give suggestions for the use of contact materials for the specified devices. For most of the contact materials , we deliberately did not indicate the exact composition and, as for Ag/SnO₂ and AgZnO, did also not include specific additives. The final material composition depends on specific design parameters of the electrical device. Advise on the special properties of specific contact materials can be found in chapter 2[[Contact Materials for Electrical Engineering| Contact Materials for Electrical Engineering ]].

==<!--6.3 -->Design Technologies for Contacts==A multitude of technologies is available and used for the actual manufacturing of contact components (see chapter 3[[Manufacturing Technologies for Contact Parts|Manufacturing Technologies for Contact Parts]]). The desired contact shape however , requires specific material properties like for example formability and weldability , which cannot be fulfilled by all materials in the same way. In addition , the design of the contact part must be compatible with the stresses and requirements of each switching device. The following <xr id="tab:Design Technologies for Contacts"/><!--table 6.2 --> combines contact design, contact material, and specific applications.

 <figtable id="tab:Design Technologies for Contacts"><caption>'''<!--Table 6.2: -->Design Technologies for Contacts'''</caption>

|All types of switches in the communications, automotive, or power distribution technology simple contact component, universally applied, selection through economic aspects

|All types of switches in the communications, automotive, or power engineering

|Contact parts for control functions and power engine- eringengineering; economical manufacturing at higher quantities

 Table 2: '''Table 6.2: Design Technologies for Contacts (Fortsetzung)'''

==<!--6.4 -->Formulas and Design Rules==

===<!--6.4.1 -->Definition of Terms and Symbols===

===<!--6.4.2 -->Contact Physics – Formulas===

===<!--6.4.3 -->Closed Contacts===

<figure id="fig:Rough flat surface">[[File:Rough flat surface.jpg|rightleft|thumb|Figure1: Rough flat surface. a) before and b) during making contact with an ideally

Fig. <figtable id="tab:Thermo-electrical Voltage of Contact Materials (against Copper)"><caption>'''<!--Table 6.63:-->Thermo-electrical Voltage of Contact resistance of crossed rodsas a function of the contact force for gold, silverand silver-palladium alloysMaterials (against Copper)'''</caption>

Table 6.3{| class="twocolortable" style="text-align: left; font-size: 12px"|-!!Contact Materials!Thermo-electrical electric Voltage of Contact Materials (against Copper0 - 100°C)[mV]|-|Pure metals|Ag<br />Au<br />Pt<br />Ir<br />Pd<br />Rh<br />Re<br />Cu<br />W<br />Mo| + 0.04<br />+ 0.06<br />+ 0.78<br />+ 0.13<br />+ 1.35<br />+ 0.08<br />+ 0.78<br />0<br />- 0.46<br />- 0.73|-|Alloys/Composite materials|AgCu 3<br />AgPd 30<br />AgPd 40<br />AgPd 50<br />AgPd 60<br />Ag/Ni 10<br />Ag/Ni 20<br />Ag/W 65<br />AuNi 5<br />AuAg 20<br />AuPt 10<br />PtW 5<br />Ptlr 10<br />Ptlr 20<br />PtRu 5<br />PtRu 10<br />PdCu 15<br />PdCu 40| + 0.026<br />+ 0.125<br />+ 0.198<br />+ 0.321<br />+ 0.412<br />+ 0.23<br />+ 0.27<br />+ 0.01<br />+ 4.7<br />+ 2.76<br />+ 1.11<br />+ 0.67<br />+ 0.56<br />+ 0.60<br />+ 0.32<br />+ 0.13<br />+ 0.180<br />+ 0.247|}</figtable>

===<!--6.4.4 -->Switching Contacts===

===<!--6.4.5 -->Physical Effects in Sliding and Connector Contacts===

===<!--6.4.6 -->General Rules for Dimensioning of Contacts===

===<!--6.4.7 -->Contact Spring Calculations===