Describe the difference between an encoder and a resolver in motion feedback.

Describe the difference between an encoder and a resolver in motion feedback.

• A. Encoder provides analog signals; resolver provides digital signals.
• B. Both provide digital position/speed via pulses.
• C. Encoder provides digital position/speed via pulses; resolver provides analog sine/cosine signals robust in harsh environments.
• D. Encoder provides velocity only; resolver provides position only.

Answer: (C)

In motion feedback, the way information is carried and how rugged the device is tend to define the difference. An encoder turns rotation into digital pulses. These pulses can be counted to track position, and their rate gives speed. Incremental encoders deliver a pulse train that your controller converts into distance moved and velocity, while absolute encoders provide a unique code for each position. On the other hand, a resolver uses a rotary transformer to output two continuous analog signals, usually sine and cosine, which encode the angle. You demodulate those signals to get the position, and differentiate the angle over time to get speed. Because sine/cosine outputs are continuous and robust to interference, resolvers are well-suited to harsh environments where dust, vibration, or EMI might affect optical or magnetic encoders. So the best description is that the encoder provides digital position and speed via pulses, while the resolver provides analog sine/cosine signals and is robust in harsh environments.

In motion feedback, the way information is carried and how rugged the device is tend to define the difference. An encoder turns rotation into digital pulses. These pulses can be counted to track position, and their rate gives speed. Incremental encoders deliver a pulse train that your controller converts into distance moved and velocity, while absolute encoders provide a unique code for each position. On the other hand, a resolver uses a rotary transformer to output two continuous analog signals, usually sine and cosine, which encode the angle. You demodulate those signals to get the position, and differentiate the angle over time to get speed. Because sine/cosine outputs are continuous and robust to interference, resolvers are well-suited to harsh environments where dust, vibration, or EMI might affect optical or magnetic encoders.

So the best description is that the encoder provides digital position and speed via pulses, while the resolver provides analog sine/cosine signals and is robust in harsh environments.