Series 1 Tachometer won't read much past 3000rpm

[Wiggles (Paul Wigton)]

Tach generator hertz to engine rpm

The S1 Tach generator should output 1V/100rpm so at 5,000rpm you should see 50V on the outputs. Unfortunately the magnets in the generator become weak with age which reduces the output voltage significantly which results in the rev counter under reading by as much as 30%. The repro tach generators are not calibrated so they are pretty useless. they also seem to fall apart with use. Best solution is to use a microprocessor board to use frequency rather than amplitude. The Hz to rpm calculation wi…