Tachogenerator is a device which generates an electrical output directly proportional to the shaft speed. The
voltage thus generated is fed to a speedometer for speed measurement and/or used as a feed-back signal for
controlling the speed of a rotating machine/equipment. In every automatic control system, since the system
performance is directly related to the TG performance, it becomes essential that the TG must satisfy certain
minimum requirements such as
Linearity : The rectified output voltage should be strictly linear with respect to the rotational speed. Output
signal: The ripple content in the rectified output signal must be as low as possible.
Temperature Effect : Variations in ambient temperature should have negligible effect on the TG output.
Long-term Stability :
Instability of output, caused due to aging of parts, shift in magnetic circuits etc. should be minimum.
Advantages ALNICO permanent magnet in the rotor assembly gives long term stable operation even
under varying ambient temperature.
Large number of poles (48) results in a high frequency output and hence good dynamic response,
linearity and wide speed control, along with low ripple content in the rectified output.
Rotor and stator assemblies are encapsulated with epoxy resin to prevent any ingress of moisture, dust
etc. Stator assembly is housed in aluminium (grade A6 IS617) body to minimize magnetic interaction
and consequent losses.
Grease filled, double shielded ball bearings are used for maintenance free operation. Two mounting
options-foot mounted and flange mounted. Speedometer can be calibrated to suit the customers
Compact and rugged construction provides longer life with excellent performance even under severe
environments. If required, TG can be supplied with rectifier unit, for DC operations