Bench test a '78 tach

[LIRS6]

Is there a way to bench test a '78 tach to get any idea of working condition? Looking at a used tach.

Thanks for any suggestions.

jason

[spuggy]

Originally Posted by LIRS6

Is there a way to bench test a '78 tach to get any idea of working condition? Looking at a used tach.

Thanks for any suggestions.

jason

It needs 12V power, ground and a signal. Very likely a nominally 5V square wave.

A $25 dollar signal generator from Flea Bay should do it. Just make sure it isn't intended for TV or radio frequencies; you probably want a 0-100KHz unit (eg audio frequencies)

My pocket DSO has one built-in, but I've never tried it...

3 impulses per revolution, 24KHz should read 8000 RPM etc.