Inland Tacho Commutator TGF-2100-02A with 7818 brush ring TGF210002A and Rotor 78H446-39
TGF-2100-02A Specification 18.9V/Krpm. 0.625" Bore. used on Inland and Servomac DC Motors such as models TT-293X, 294X, 450X, 530X, 580X, 950X
A Tacho is fitted with permanent magnets in the stator which will create a magnetic field. An amplitude continuous voltage proportional to the speed, depending on the rotation direction is generated in the wound rotor. You can see a big picture of the three components in the technical tab below.