Hi am Mohan i would like to get details on tachogenerator working principle ppt ..My friend Justin said tachogenerator working principle ppt will be available here and now i am living at salem and i last studied in the college/school erode sengunthar engg college and now am working as asst professor @ erode sengunthar engg college. pls help me out

The WEG tachogenerators have been designed for applications
on servocontrol operating machines, driving of textile
machines, accelerators, braking of elevators, control and regulation
of fine adjustments which depend on speed variation
and other applications that require continuous and closely
controlled speed.
The tachogenerator gives a continuous voltage sign corresponding
to the speed actual value of the electric machine to
which it is coupled.
1.2.CONSTRUCTION
The Tachogenerator is fitted with permanent magnets in
the stator with the function of creating a magnetic field. An
amplitude continuous voltage proportional to the speed, which
depends on the rotation direction, is generated in the wound
rotor.