Wanted Hall effect Tach

[Vietti]

I'm looking for a small, Hall effect tach with an onboard power source. See some on Amazon but most require an external power source.

I cobbled one together with a 9 volt battery taped on the side and it worked ok. Today I fried it as it is now giving bogus high rpm readings. Apparently I got the sensor or something too close to the powerful magnets in my magneto. Don't know if I damaged the hall effect sensor or the module. May have to go to a photocell device.

TIA, John

 

[Rdean33422]

I have one of these and it works great. No connection to the engine except a couple of wraps around the spark plug
wire.
https://www.ebay.com/itm/165233432684
Ray

 

[Vietti]

Thanks Ray, Ive tried those and they work marginally well on a high tension mag but not at all on a low tension mag-my voltages are just too low.

I'm using the tach with a test stand to measure low tension mag outputs, we are talking a few volts.