From a performance standpoint, encoders have a lower weight and rotational inertia than resolvers, making them more suitable for applications with high acceleration and deceleration rates. In addition, the conversion rate of the RDC limits a resolver’s maximum speed, and resolvers lose some accuracy when the application encounters rapid speed changes, as is often the case with servo motors. Encoder accuracy is typically in the range of 20 arcseconds, which is much better than the 3 arcminute range of resolver accuracy. Another advantage that makes encoders a more attractive option is that they can be upgraded by replacing the feedback element and changing software, whereas changing a resolver would potentially require a change in the converter, filter, supply voltage and frequency.

Weighing the benefits and drawbacks of both resolvers and encoders, the deciding factor on which is the best alternative will often be environment. For applications that involve shock loads, vibrations, or high temperatures, resolvers are a more robust solution. But encoder designs are becoming more rugged and reliable, and they can now withstand conditions that would previously require a resolver. This improved durability, in conjunction with their ease of use, explains why encoders are becoming the preferred choice over resolvers.