On Tuesday 10 December 2013 15:19:27 Dave Cole did opine: > On 12/10/2013 11:58 AM, andy pugh wrote: > > On 21 October 2013 18:21, Les Newell <les.new...@fastmail.co.uk> wrote: > >> A trick to get around this is to use a 24V transformer to buck the > >> mains down to 216V. Add the voltage doubler after that and your DC > >> is spot on. > > > > You seem to understand transforners :-) > > > > I am wondering what I can do with this one, that I found in a skip. > > > > Ideally I would like a 100V isolated supply, just to be a bit less > > scary when messing about with servo motors. > > (Rectified UK mains is 300V + ) > > > > This is the label on top: > > https://drive.google.com/file/d/0BxjJW1-T6n7Cd2FrOWV5R3dRZnFhV2xrV0F3O > > Hp3UW05X2NF/edit?usp=sharing > > That could work. > > The bottom two bars with the numbers under them represent the Primary > windings and the associated taps. > > The top two bars represent the secondary windings. > > The "Verbdg" is the connections needed to make to get the desired > voltage out of the secondary when applying voltage to the primary. > > So for instance, if you connect terminals 20 and 26, and 23 and 28 > together and apply 220 volts to those two nodes (incoming power). > And connect 37 to 39 and 36 to 38 (wiring the secondary coils in > parallel), then you will have 110 VAC power available at terminals 37 > and 36. > > To further lower the secondary voltage you may be able to fully parallel > the primary by connecting 20-25 and 24 to 28, but there may be some > reason why that cannot be done. The diagram does not show that. You > could try it, but I'd put a circuit breaker in each primary winding > connection (you will need two) just in case there is a problem doing > that, then power up the transformer with no load and put a clamp on > ammeter on each primary winding to make sure you don't have some > circulating currents. The breakers are a "just in case" so the > transformer doesn't melt down in case that is an incorrect connection. > Having some circuit breakers on the primary feed is also a good idea in > case this transformer was discarded due to failure. Safety glasses are > advised. :-) > > Dave > > > ------------------------------------------------------------------------ > ------ Rapidly troubleshoot problems before they affect your business. > Most IT organizations don't have a clear picture of how application > performance affects their revenue. With AppDynamics, you get 100% > visibility into your Java,.NET, & PHP application. Start your 15-day > FREE TRIAL of AppDynamics Pro! > http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.cl > ktrk _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users
Dave, you probably have it better than I do. Cheers, Gene -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Genes Web page <http://geneslinuxbox.net:6309/gene> Caller: I just installed Windows 95 on my computer. Tech Support: And...? Caller: It's not working. Tech Support: You already said that. A pen in the hand of this president is far more dangerous than 200 million guns in the hands of law-abiding citizens. ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
