Building a transformer
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From: ian field on 8 Aug 2006 17:19 "Jim Thompson" <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com> wrote in message news:99uhd21d83biuj4122hfrv1p47k4gip41h(a)4ax.com... > On Tue, 8 Aug 2006 13:44:27 -0700, "RST Engineering \(jw\)" > <jim(a)rstengineering.com> wrote: > >>What primitive semiconductors did you use in the output stage, or was it a >>toob device? Did we have 2N3055s in '75? I don't memember. >> >>Jim >> > [snip] > > I'm trying to remember what semiconductors I used. But, IIRC, > 2N3055's *were* available around that time. > > ...Jim Thompson > -- > | James E.Thompson, P.E. | mens | > | Analog Innovations, Inc. | et | > | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | > | Phoenix, Arizona Voice:(480)460-2350 | | > | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | > | http://www.analog-innovations.com | 1962 | > > I love to cook with wine. Sometimes I even put it in the food. Was it Ge or Si ?
From: ian field on 8 Aug 2006 17:21 "John Woodgate" <jmw(a)jmwa.demon.co.uk> wrote in message news:uh2dkFx6oO2EFw8t(a)jmwa.demon.co.uk... > In message <44d8d62e$0$26602$da0feed9(a)news.zen.co.uk>, dated Tue, 8 Aug > 2006, Mark Fortune <mark(a)fortrex.co.uk> writes > >>So where do I start? what type of core is best for this application? - I >>have a friend who's blasting off that toroids are best, but i'd like a >>second opinion, and what kind of wire to use for the primary and >>secondaries? what are good safety practices regarding insulation? Is this >>even a feasable project to undertake (moreso on the money side than >>timewise). Any other advice also greatly appreciated. > > You need more than 5 A AC to get 5 A DC. The rough rule is that a bridge > rectifier needs a factor of 1.6 times, but with modern huge filter caps, > think of at least 1.8 times. That's a BIG transformer, with THICK > secondary wire. Not a project to learn on, I would say. > > It's not even easy to buy parts for transformers now. Maplin used to do > kits - bobbins, laminations etc. , but not now. > > To learn about transformer design, you need a textbook and one of the best > is a classic - Radio Designer's Handbook, by F Langford Smith, which was > reprinted by Newnes (Butterworth-Heinemann/Reed) a few years ago. ISBN0 > 7506 3635 1. > > Modern core material (silicon-iron) is better than the materials mentioned > in the book. You may be able to get the information on current materials > (maximum recommended induction, core loss power/kg, magnetizing VA/kg) > from the web. > -- > OOO - Own Opinions Only. Try www.jmwa.demon.co.uk and www.isce.org.uk > 2006 is YMMVI- Your mileage may vary immensely. > > John Woodgate, J M Woodgate and Associates, Rayleigh, Essex UK You can't beat a microwave oven transformer with a secondary transplant!
From: Jim Thompson on 8 Aug 2006 17:25 On Tue, 08 Aug 2006 21:19:21 GMT, "ian field" <dai.ode(a)ntlworld.com> wrote: > >"Jim Thompson" <To-Email-Use-The-Envelope-Icon(a)My-Web-Site.com> wrote in >message news:99uhd21d83biuj4122hfrv1p47k4gip41h(a)4ax.com... >> On Tue, 8 Aug 2006 13:44:27 -0700, "RST Engineering \(jw\)" >> <jim(a)rstengineering.com> wrote: >> >>>What primitive semiconductors did you use in the output stage, or was it a >>>toob device? Did we have 2N3055s in '75? I don't memember. >>> >>>Jim >>> >> [snip] >> >> I'm trying to remember what semiconductors I used. But, IIRC, >> 2N3055's *were* available around that time. >> >> ...Jim Thompson >> -- >> | James E.Thompson, P.E. | mens | >> | Analog Innovations, Inc. | et | >> | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | >> | Phoenix, Arizona Voice:(480)460-2350 | | >> | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | >> | http://www.analog-innovations.com | 1962 | >> >> I love to cook with wine. Sometimes I even put it in the food. > >Was it Ge or Si ? > It was Silicon. I didn't use any Germanium power devices since I boosted my car radio back when I was a junior in high school. ...Jim Thompson -- | James E.Thompson, P.E. | mens | | Analog Innovations, Inc. | et | | Analog/Mixed-Signal ASIC's and Discrete Systems | manus | | Phoenix, Arizona Voice:(480)460-2350 | | | E-mail Address at Website Fax:(480)460-2142 | Brass Rat | | http://www.analog-innovations.com | 1962 | I love to cook with wine. Sometimes I even put it in the food.
From: mc on 8 Aug 2006 17:36 I would look at cheap battery chargers. Note that you can put the primaries in parallel and the secondaries in series to get a higher output voltage by using multiple transformers. Check phasing if you do this.
From: Mark Fortune on 8 Aug 2006 17:39
John Woodgate wrote: > In message <44d8d62e$0$26602$da0feed9(a)news.zen.co.uk>, dated Tue, 8 Aug > 2006, Mark Fortune <mark(a)fortrex.co.uk> writes > > You need more than 5 A AC to get 5 A DC. The rough rule is that a bridge > rectifier needs a factor of 1.6 times, but with modern huge filter caps, > think of at least 1.8 times. That's a BIG transformer, with THICK > secondary wire. Not a project to learn on, I would say. I think what you're saying is "try learning on some smaller transformers first" I might just do that, cos it'd be a PITA if I screw up on a big one and have to unwind it all again :] > > It's not even easy to buy parts for transformers now. Maplin used to do > kits - bobbins, laminations etc. , but not now. > > To learn about transformer design, you need a textbook and one of the > best is a classic - Radio Designer's Handbook, by F Langford Smith, > which was reprinted by Newnes (Butterworth-Heinemann/Reed) a few years > ago. ISBN0 7506 3635 1. Thanks for the info, i'll try and get my library to order a copy. > > Modern core material (silicon-iron) is better than the materials > mentioned in the book. You may be able to get the information on current > materials (maximum recommended induction, core loss power/kg, > magnetizing VA/kg) from the web. I'll have a look, thanks |