Abstract-Direct current analog tachometer generators are used extensively in industry to provide speed signals for use with instrumentation,and in feedback loops for closely regulating the
speeds of drive systems. The accuracy of these tachometers is affected by changes in environmental conditions (such as temperature) to which they are exposed.
By using proper design techniques along with the proper materials, these effects can be virtually eliminated.
Another potential source of inaccuracy is related to the condition of the surface film of the commutator of the tachometer which, in turn, is influenced by the value of the ohmic resistance of the external load connected across its terminals. By properly designing the external circuitry, inaccuracies resulting from this source can also be reduced to an insignificant level.
This paper describes these effects in some detail and offers practical suggestions for optimizing the accuracy of these devices by proper design and usage in electrical circuits.