erik,

the output of the acceler. is 3.6v. However I used both a Schmitt trigger and later an inverter to give a clean 5v out - but with no success.

Also I don't know if I said this but when the acceler is at rest 50% of each period is high and 50% is low thus there is always an edge to catch.

Sorry if I am interpetting your reply wrong.

Thanks for your help,

Seamus.