Welcome to electrical and electronics engineering discussion website, Please login or register to continue.

4 views
by
What is tachometer ? Explain photo electric pick-up

Your answer

Thanks for your contribution. Feel free to answer this question. Please avoid short answer. Your answer is most welcome. Be genuine.

Upload image or document:

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
Are you a robot ? (Y = Yes / N = No)
To avoid this verification in future, please log in or register.

1 Answer

0 votes
by

Tachometer is an instrument which is used to measure angular speed. It is measured in revolutions per minutes (RPM).

image

Working: Working principle:The light passes through the holes available on the rotating disc with a specific interval, depends on the angular speed of disc having equidistant holes. The frequency of this light pulses is measure of angular speed of the disc. It consists of an opaque disc on the rotating shaft.The disc has a number of equidistant holes on its periphery.At one side of the disc a light source is fixed like LED and on other side of the disc, and on the line of the light source, alight sensor like phototube or some photosensitive semiconducting device is placed. When a hole appears between two,the light following upon the sensor produces an output pulse. The frequency at which the pulses are produced depends on the number of holes in the disc and its speed of rotation. Hence the speed is given by 

N=f/HS 

N=speed 

f=frequency 

Hs=holes on the disc 

Welcome to Q&A site for electrical and electronics engineering discussion for diploma, B.E./B.Tech, M.E./M.Tech, & PhD study.
If you have a new question please ask in English.
If you want to help this community answer these questions.

...