You don't have an old automotive battery trickle-charger around, do you Walt? -like say a 10 amp? That's what I used after making a few changes to get both AC and DC current out of it. But, some of the newer ones have circuitry in them that won't allow current flow until hooked up to a battery. Those don't convert well to an etcher (at least Ernie and I couldn't come up with an easy way to use them). I had the charger, and hardly ever used it, so it didn't cost much to get an etcher going. It seems to work very well- nice deep and sharp results. I think (if I remember correctly), I spent about $50 - $60 on stencils- enough to last me a long time.
Bill