latest innovation i'we made is just simple speed controller for fan, my shop/room is SO hot to work/sleep otherwise, and fan is way too loud to use at even normal speed. it's not very efficient way thought, around 41% efficiency.....just run is by isolated variac, but i have in mind to make encased variac without isolation, for other purposes too. I have excess 230v/0.5A, should be good for small power, it needs only meters/fuses and all case stuff. no worries, i won't probe it with scope!