got one:
http://www.harborfreight.com/cpi/cta...emnumber=43060

works like a charm on 3 different motors I tried: a grinder from
Lowes, Craftsman trimmer and another trimmer from HF.

There were reports about difficulties with slow-start motors
but as you see I didn't have any problems. Was able to get all 3 to
start at the lowest RMP setting of the control and change the RMP
accross the whole range.

Just a PSA, no affiliation