Comparing Incremental Encoders And Resolvers

During CNC machining, discerning the positioning of the cutting tool and workpiece is vital. This is performed with the aid of digital encoders. A popular example is incremental encoders that convert the angular movement or linear motion of a shaft into a digital reading to identify the position or motion. While not as accurate as absolute encoders, they are still extremely accurate for their price range. Another piece of equipment often compared to them is resolver encoders. This blog will cover the major differences between incremental and resolver encoders. 

Design Of Incremental Encoders

An incremental encoder mainly consists of a spindle, a PCB and a cover. The PCB is further made of a sensor array that has two primary signals designed for position and speed. Based on its mechanism, that is, whether it is an optical or magnetic encoder, the actual working parts differ slightly. Whereas the former uses an optical sensor, the latter employs magnetic sensors and magnetic poles on the disc.

Basic Design Of A Resolver

A resolver is a more rudimentary version of an incremental encoder. It comprises two windings set perpendicular to one another. One of them is attached in place, whereas the other moves with the object. The variation in magnetic strength and position between the two windings helps determine the motion of an object.

Due to its rather simplistic design, a resolver encoder has a distinct advantage and a disadvantage. While the rudimentary design makes it perfect for extreme conditions such as temperature fluctuations, shocks, vibrations, and even radiation exposure, it loses accuracy in more complex applications. Furthermore, they can only send output in analog format, requiring more electronics to make it more accessible.

Therefore, unless the conditions are very extreme such that an incremental encoder will fail to operate, it is best to not opt for a resolver.

Walker Machinery is a proud distributor of digital encoders and digital readout systems made by Heidenhain and Acu-Rite. Our experts can help you discern the perfect encoder for your application. For more details, contact us at 905-876-0890 today.