An example controller includes a feedback circuit coupled to provide feedback information representative of an output of the power converter during at least a portion of an OFF time of a power switch. The electrode assembly may be effectively fixed inside a can as a pressure-sensitive adhesive tape attached to an outer circumferential surface of the electrode assembly is formed into a 3D shape by an electrolyte. A heater 22 heats air flowing into the chamber 14 via inlet 16 to a temperature of between 110\xb0 C.