The particular circuitry described was chosen because the components were available. It is only one way of implementing the scheme and space and probably cost could be reduced by using solid state components where possible.
As mentioned, the device does not require a direct connection to the rotating part and if a known frequency, e.g. mains, is used as the input to the reference counter, it can function as a shaft speed indicator.
Get full access to this article
View all access options for this article.
References
1.
FitzgeraldA. E., and KingsleyC.Electric Machinery (2nd Edition). McGraw-Hill (1961).
