Why We Use Redundant Circuits

Posted on Thursday, July 20, 2017 in UEA Blog

Some things are better left unchanged... no really some things are.  For example, the first slip ring assemblies UEA manufactured back in 1961, 56 years ago, had redundant contacts and that still holds true today.  UEA uses a double pivot two-brush assembly with a common spring applying the force needed to maintain a high contact pressure.

redundant circuits

Besides being a simplified design, this configuration has many benefits over a single fixed brush design.  With two separate contact points, there is a much higher contact reliability. This is due to an overall increased brush-face cross sectional area.  Also the brushes are spaced approximately 90 degrees apart providing for minimal shock and vibration fatigue.  No matter the direction of the impact, both brushes can’t receive 100% of the transitive shock.  By always remaining one contact at the very least this nearly eliminates the potential for arcing to occur.  The brush is designed in a way that even at maximum ampacity the assembly can survive for short durations with one of the brushes lifted off of the ring in a worst-case scenario. 

In normal operating conditions, the two brushes also help distribute the electrical load across the slip ring.  As many of our slip rings go on products that see oscillation type movements, they’re less likely to have any single section of the ring wear more than the rest.  All of this was conceptualized within the original design intent. The double pivot dual brushes continue to be the best design even in the 21st century because they provide a very good design for communication type circuits.  In contacts where even single bit of loss is a factor, increasing the number of contacts helps improve reliability exponentially.

This is why UEA is sticking behind our brush assembly concept, even though there have been several dozen tweaks along the way. If you would like more information about our brush assembly and how it can benefit you, please contact us!

Kyle Riegel

R&D Engineer