How does a Slip Ring work?

A slip ring is an electrical connector designed to carry current or signals between a stationary wire and a rotating device.

Typically, it is comprised of a stationary graphite or metal contact (brush) which rubs on the outside diameter of a rotating metal ring. As the metal ring turns, the electrical current or signal is conducted through the stationary brush to the metal ring making the connection. Additional ring/brush assemblies are stacked along the rotating axis if more than one electrical circuit is needed. While simple in concept the rubbing of the brush against the metal ring causes wear which changes the quality of the electrical connection.

This simple design has been used for decades as a rudimentary method of passing current into a rotating device. Some other names used for slip ring are collector ring, rotary electrical contact, electrical rotary joints or union, and "electrical slip ring". Some people also use the term commutator, however commutators are somewhat different and are specialized for use on DC motors and generators.

Mercotac brushless slip rings employ a unique design principle that sets them apart from traditional sliding, brush-type slip rings. Instead of using brushes to establish contact, the connection is made through a pool of liquid metal that is molecularly bonded to the contact points. This design provides a stable, low-resistance connection that does not wear down with rotation. There are many reasons why Mercotac products are superior to traditional slip rings:

  • NEAR ZERO NOISE: Unlike brush-type slip rings, Mercotac products produce very little electrical noise due to their innovative design.
  • LOW RESISTANCE: The resistance through the rotating contact is less than one milliohm, which is much lower than what one would get with a brush slip ring.
  • NO SIGNAL DEGRADATION: Mercotac products maintain signal integrity over time, whereas brushed slip rings can degrade the signal.
  • NO MAINTENANCE: Brushed slip rings require regular maintenance, but Mercotac brushless slip rings are maintenance-free.
  • COMPACT & AFFORDABLE: Mercotac products are more compact and cost far less than traditional slip rings with the same capacity. For a more detailed explanation, you can watch the video at the top of this page.

Our FAQ Page goes into more details about how Mercotac® Brushless Slip Rings are different from and superior to traditional slip rings.

Many industries have found the superior performance of Mercotac® connectors to be the answer for their slip ring assembly problems and requirements.

Click here to see video clips demonstrating the Mercotac® connector in action

Guidance for using Mercotac® Brushless Slip Rings in engineering designs.

Learning Center Construction & Materials

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Learning Center Electrical Characteristics

Learn about Mercotac® Electrical Characteristics: Voltage Rating, Current Rating, Contact Resistance, Circuit Separation, Operating Temperature, Frequency.
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Learning Center Rotational Characteristics

Learn about Mercotac® Rotational Characteristics: Rotational Speed, Rotational Torque.
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