The encoder is a solid-state device which produces a digital output, unlike the mechanical resolver.

Differences between encoder and resolver

• Encoders emit pulses that signify acceleration over a short period; recording such pulses indicates range and testing the order of pulses in channel A vs channel B indicates position. While the resolvers produce a series of sine or cosine wave representing an absolute location within a single revolution, such signals are usually transformed into digital signals by utilising a resolution interface frame.
• The input signals of encoders are usually powered with the DC voltage. On the other hand, the resolvers are triggered by an AC reference sine wave and are usually generated with a specific resolver power supply. This power supply is generally operated by basic DC voltage.
• Encoders usually have all of their onboard circuitry, reducing interconnections while restricting operating temperatures. But the resolver systems usually place the resolver power supply, and interface board close the input panel, demanding significant inter-unit cabling, thus enabling the solver to survive higher temperature conditions.
• The major applications of the encoder are in AC induction motor speed and position control. In addition, their application is also found in DC motor speed and position control. They can be used in AC and DC servo motors. While the applications of resolvers are in permanent magnet (PM) motor communication and speed control and can be used for AC and DC servo motor communication and speed control.