None?
A DS1820B sensor in one of the tubes, ceramic heating rod/elements (I'd go 12V), some 12V High current MOSFETS and a beefy 12V power adapter...
None?
A DS1820B sensor in one of the tubes, ceramic heating rod/elements (I'd go 12V), some 12V High current MOSFETS and a beefy 12V power adapter...