Both the Silvergen and Silverpuppy are constant current and self stirring generators. They are not AC though. The DC process is safer for home use and you don't have to baby sit it like you do for AC. I have a simple AC unit that does 5 gallons at a time but I really have to watch it. It is not as sophistiacated as the Silvergen and Silverpuppy which are plug and play CS gens. I had both of those units and loved them. I sold them because I needed to make large amounts of CS in a shorter time frame.