When selecting a transformer, it is not sufficient to just get a 1:1 ratio. The core must not be allowed to saturate. If you take a 120 VAC rated 1:1 ratio isolation transformer and try to operate it on 240 VAC it will likely saturate. When the core is in saturation the normal back EMF does not develop and the winding will look nearly like a short circuit. Not a good thing! Going the other way, operating a winding at less than its rated voltage, is OK. You just get less than the full power that the core is capable of handling.
Steve Stallings -----Original Message----- From: andy pugh [mailto:bodge...@gmail.com] Sent: Wednesday, September 07, 2011 4:35 AM To: Enhanced Machine Controller (EMC) Subject: Re: [Emc-users] Servo PSU On 7 September 2011 07:53, Peter Blodow <p.blo...@dreki.de> wrote: >> Yes, but I can't find one. (or not one rated at 15A / 240V anyway) > Andy, I have one here that will deliver this power easily. It used to > power a hospital supply where all electrical gear must be floating. The > only problem would be the shiping since it is very heavy. Where are you, > anyway? I am in the UK, and I just realised that I do have a transformer, on fact I have been using it all along during the development phase, a safety isolating transformer. It is interesting watching this conversation develop, as Pete and Dave are both of the opinion that what I have is entirely conventional for a servo drive. I have also just noticed that the transformer I rescued from the skip at work (A 1160VA Siemens one) might work, if I can find a combination of winding taps that gives 1:1. Thanks for the offer, though. -- atp "Torque wrenches are for the obedience of fools and the guidance of wise men" ---------------------------------------------------------------------------- -- Using storage to extend the benefits of virtualization and iSCSI Virtualization increases hardware utilization and delivers a new level of agility. Learn what those decisions are and how to modernize your storage and backup environments for virtualization. http://www.accelacomm.com/jaw/sfnl/114/51434361/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Using storage to extend the benefits of virtualization and iSCSI Virtualization increases hardware utilization and delivers a new level of agility. Learn what those decisions are and how to modernize your storage and backup environments for virtualization. http://www.accelacomm.com/jaw/sfnl/114/51434361/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
