Yeah, but.... I still say that the thing that limits the secondary current is the wire gauge used for the secondary winding.
I don't think many transformers are built using wire that's a lot heavier than needing fro rated output current. Therefore, dropping the primary voltage(thereby dropping the secondary voltage) doesn't mean you can now pump more current through it to "get back" up to the VA rating. Andy Wander Verrex Corporation -----Original Message----- From: Jon Elson [mailto:[EMAIL PROTECTED] Sent: Sunday, October 24, 2004 11:30 PM To: [EMAIL PROTECTED] Subject: Re: [CAD_CAM_EDM_DRO] current rating of transformers Andy Wander wrote: >Jon: > >I could be wrong, but I think you're confusing transformer output with >stepper input here...:) > >If I am correct, the current rating in a transformer has mostly to do with >the gauge wire used, and if half the winding can take 10A, so can the full >winding. > > No, it is a bit more complex. If you use the 2-diode full-wave scheme with the center tap, each half of the winding draws current only every other half-cycle, thereby giving it a "rest" or reducing the duty cycle. Of course, you also get half the voltage that way, compared to a full-wave bridge using the full winding. That also explains why the transformers have VA ratings. If you reduce the output voltage, you can get more current to equal the same V*A. Also, the capacitor input filter draws current in pulses, which reduces the rating of the transformer further. > > Jon Addresses: FAQ: http://www.ktmarketing.com/faq.html FILES: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/files/ Post Messages: [EMAIL PROTECTED] Subscribe: [EMAIL PROTECTED] Unsubscribe: [EMAIL PROTECTED] List owner: [EMAIL PROTECTED], [EMAIL PROTECTED], [EMAIL PROTECTED] Moderator: [EMAIL PROTECTED] [EMAIL PROTECTED] [EMAIL PROTECTED] [Moderators] URL to this group: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO OFF Topic POSTS: General Machining If you wish to post on unlimited OT subjects goto: aol://5863:126/rec.crafts.metalworking or go thru Google.com to reach it if you have trouble. http://www.metalworking.com/news_servers.html http://groups.yahoo.com/group/jobshophomeshop I consider this to be a sister site to the CCED group, as many of the same members are there, for OT subjects, that are not allowed on the CCED list. NOTICE: ALL POSTINGS TO THIS GROUP BECOME PUBLIC DOMAIN BY POSTING THEM. DON'T POST IF YOU CAN NOT ACCEPT THIS.....NO EXCEPTIONS........ bill List Mom List Owner Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
