Diesel Tachometer

[tests]

My Dad has a Diesel tractor and he wants me to build him a tachometer for it. He doesn't want any digital electronics on it. What would be the best way to generate a pulse off of the flywheel to use with a regular tachometer?

 

[aviat]

Stewart Warner have been making tach's for a long time. They still have analog ones.

http://www.stewartwarner.com/index1.html

 

[Comcokid]

I've seen this kind of question before. The following are links to discussions on similar topics.
thread67-116112
thread67-80211
thread67-110687

 

[BrianR]

A straightforward solution is to use the National Semiconductor LM2917 chip which is designed for this application.

http://www.national.com/pf/LM/LM2917.html

It is compatible with an inductive pickup that you can position close to bolt holes on the flywheel. The pickups have a coil and a magnet so will detect a passing magent, a metal object or a hole.