Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!unix.cis.pitt.edu!dsinc!wells!k3tx From: k3tx@wells.UUCP (Dave Heller) Newsgroups: sci.electronics Subject: Re: Xformer sources needed Message-ID: <908@wells.UUCP> Date: 24 Jan 91 14:18:54 GMT References: <36148@netnews.upenn.edu> Distribution: usa Organization: Wells Computer Systems Corp., Levittown, Pa. 19058 Lines: 53 In article <36148@netnews.upenn.edu>, depolo@eniac.seas.upenn.edu (Jeff DePolo) writes: > > I've been running in circles trying to find a source for high-current > transformers for a 120 AC to 13.8 DC supply. The prices for most of > the commercial supplies around (Astron, et. al.) seem ridiculously high. > I'm hoping to find a transformer that will handle a solid 35A. > > Any info would be greatly appreciated (except suggestions to roll my own) :-) > > --- Jeff > -- > -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- > Jeff DePolo N3HBZ Twisted Pair: (215) 386-7199 > depolo@eniac.seas.upenn.edu RF: 146.685- 442.70+ 144.455s (Philadelphia) > University of Pennsylvania Carrier Pigeon: 420 S. 42nd St. Phila PA 19104 What's wrong with a roll-your-own job? You're talking about something in the 500+ watt range, which is *heavy* and to buy new could be on the expensive side. But there are plenty of *big* transformers around practicallyl for the taking --- usually with 120 v in, but sometimes with 240 v primaries, which would be better. So you find a roll of #12 or #10 insulated wire, start putting turns on the core where they can be fit, and before long you have enough volts coming out --- then four (4) big but cheap diodes bridged and you have what you wanted in the first place. A *big* surplus condenser across the output and the ripple isn't too big, maybe. Or maybe find a transformer from a junked welder or industrial battery charger and you have it made. Carrying the thing could pose a problem. *heavy*. Or another wild but actually practical suggestion: I've seen *many* junked computers and major components thereof in scrap yards, and many of these have multiple transformers in the range you note. Those possessing them have no idea what they are and emphatically don't want to know and are very happay to sell by the pound. Or, if you want a pig, I have one for the taking, which with 120 on the secondary might give you what you want on the primary. Free for the taking on condition I don't get it back. In summary, you ask for what can be very expensive if *bought* but can be very *cheap* if scrounged. Take your pick. K3TX