The term ‘ring encoder’ is typically used to describe a large diameter rotary or angle encoder with a hollow centre. Most ring encoders employ an optical technique with a ring shaped optical grating which rotates relative to a stationary electro-optic transducer. Optical ring encoders are well-suited to applications where the rotor’s movement can be precisely constrained relative the sensor’s read ahead and where dust or foreign matter cannot interfere with the operation of the sensor.
However, in harsh environment applications (notably with condensation or dust), or applications where the rotor’s movement cannot be precisely constrained, optical ring encoders often prove unreliable and unsuitable. For such applications, inductive ring encoders offer the ideal solution.
Unlike optical ring encoders, Zettlex ‘IncOder’ inductive ring encoders use a transformer or inductive technique to accurately measure angular position and speed. IncOders are well-suited to tough conditions where traditional optical technology might prove unreliable.
IncOders have 2 parts – a Stator and a Rotor. Each part is a flat ring and accommodates through-shafts, slip-rings, optical-fibres, pipes or cables. The Stator is powered and the Rotor is passive. The Stator contains all the electronics required to receive power and generate an absolute output signal. The signal shows the true absolute position of the Rotor without requiring any motion. There is no need for any special couplings and the Rotor & Stator can be screwed directly to the host product. Importantly, with no bearings the products are not adversely affected by foreign matter. IncOders can be fully submerged in water or oil, and precise mechanical mounting is not required.
With no contacting, delicate or wearing parts, inductive ring encoders do not require servicing or maintenance, providing true ‘fit and forget’ solution.
Fig.1. Zettlex ‘IncOder’ inductive ring encoders are well-suited to tough conditions where traditional optical technology might prove unreliable.