Electronic – cheap and accurate electromechanical method to provide a configurable counter-torque

measurementmotortorque

Given a continuously rotating motor shaft, is there a cheap and accurate electromechanical method that would provide a configurable counter-torque?

Rotation is in one direction only, RPM range is 0 – 12000, torque range from 0.001 to 1 Nm.

edit: Before the edit I was asking for a constant counter-torque regardless of the motor's RPM. I have removed this as it just adds complexity, increases cost and is not strictly necessary IF the magnitude of the counter-torque is precisely known at whatever RPM the motor's shaft is currently spinning at.

Best Answer

Do you understand the concept behind using the Prony Brake for measuring torque?

You can use electromechanical feedback (a simple servomechanism) to maintain constant torque at arbitrary speeds.