turbulatordude wrote: >--- In [EMAIL PROTECTED], Jon Elson <[EMAIL PROTECTED]> wrote: > > >>turbulatordude wrote: >> >> >> >>>Hi, >>> >>>If I have a 24 volt, (12V-0-12) center tap transformer like the >>> >>> >MPJA > > >>>unit. >>>http://www.mpja.com/productview.asp?product=7846+TR >>> >>>And isolate the center tap I get 24 volts. >>> >>>But when rectified, doesn't the current change also ? >>> >>>There is a note in the catalogue that for this wiring the amps are >>>1.8x >>> >>>The catalogue refers to required ouput amps >>> >>> >>>full wave bridge cap input filter 1.8x to required output amps >>>full wave choke input filter = required output amps >>>full wave, center tap, cap = 1.2x roa >>>full wave, center tap, choke = 0.7x roa >>> >>> >>> >>> >>Using the full winding means current flows in both ends of the >> >> >winding > > >>all the time. So, the current rating must go down. With full-wave >>center tap, each half of the winding gets a rest 50% of the time, so >>current rating goes up. I guess what they are saying here is that >> >> >you > > >>take the load current and multiply by these factors to get the >> >> >rating > > >>of the transformer. >> >>Jon >> >> > > >This is where I'm confused. > >If I use the full winding, 24 volts, do I really get 5.8 amps ? >and with center tap, 12 volts, 8 amps >but using a choke at 24 volts, I can get the full 10 amps ? > Yes, probably. But, inductor input filters usually have poor regulation, meaning the voltage droops substantially under load. But, the peak currents in the transformer will be greatly smoothed out, so the RMS rating of the transformer is fully available. Capacitor input filters draw strong pulses of current right around the voltage peak, and this is a worst-case situation for copper losses. So, all capacitor input filters will deliver less current from the transformer for the same heating.
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/
