Rotary encoder
= Rotary encoder
{wiki}
A <rotary encoder> converts shaft rotation into a readout of <angle> or changes in <angle>. The PS-2120A uses interruptions of a <light> beam to encode shaft motion; its product specification gives 4000 divisions per revolution. That count is a resolution specification, not a guarantee of the precision of an inferred <angular acceleration> or <moment of inertia>. <PASPORT Rotary Motion Sensor - PS-2120A>{ref}