I found some large toroids (about 2 to 2.5 inch and about $2 something apiece) at BG Micro, so I ordered forty some dollars worth. They must be heavy, ‘cuz the UPS charges were nearly half the price of the order! I’m gonna wind some heavy duty Joule Thiefs or something like that. Maybe make a CFL tube driver. Still, they’re cheaper than other places.
More about these toroids and how I connected them up to a V boost circuit in my blog here.