Optical encoders for small drives

Rotor position and speed information is essential for the control of motors, In fact, several encoders for motors with diameters greater than 13 mm already exist on the market, but most of the solutions are too expensive or unsuitable for smaller applications. Considering the low cost of small drives and their growing number in automation systems, there is a need for encoder solutions which do not increase overall system cost, but offer a controllable device, After a brief summary of existing angular encoders, their miniaturization problems are highlighted, followed by suggestions of suitable architectures for small devices.