Louvered Contact Band
The final level of achievable power transmission when using contact band is dependent upon several parameters. Some of which are dependent upon best practice, the choice of material and quality of workmanship. Others are variable by design and adoptable to application requirements.
Although it is possible to use any conductive material for the connector components the most common metals used are copper(1), aluminum(0.75) or brass(0.6). The numbers in brackets indicate a ball park figure for determining conductivity factors based on copper having a factor 1.
For surface protection the most common plating used is silver. Gold will mainly be used for applications in aggressive environment although there are further reasons such as in applications underlying micromotion between the connector components.
The current loading capability of the contact bands themselves is mainly influenced by their physical design by the base material, the material thickness, surface plating and by the number of contact points per defined footprint. For two contact bands with all parameters being the same but the number of contact points being different the one with more contact bridges will allow a higher load of power transmission.
This is one reason for Louver_tron 313 with a contact bridge spacing of 2mm being superior to Louver_tron 317 with a contact bridge spacing of 2.5mm.
Contact Bands themselves are much lower in mass than the metal components in a connector and therfore their thermal capacity is much lower. They are depending upon the heat soaking capability of the metal connector components to quickly dissipate their heat which will generate under load. This pertains to the choice of the material for the metal connector components as well as the minimum cross section of these components that is required to handle the load.
Nominal current rating for electrical contacts are usually quoted in conjunction with allowable temperature rise. When assuming a defined temperature rise of max. 40°C a connector made up with steel components for example will reach this max. temperature rise at a lot lower current load than a connector that is made up of copper components.