The author built 2 different Electrolysis builds to remove rust. One with an old car battery charger, the other from an old PC power supply. Me…I would do the PC power supply (easier to come by). A few other things I would do differently. One is to wire in a switch to the power supply. Second is to use wires that are insulated to connect the iron rods. Call it paranoia, but I don’t want to accidentally get zapped if I can avoid it. I did find it interesting the author used PH increaser for the water instead of salt.
https://www.instructables.com/id/RUST-Removal-Using-Electrolysis/