Transformer current rating calculation
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

 Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
 23rd August 2007, 03:55 PM #1 Roy3932   diyAudio Member   Join Date: May 2007 Transformer current rating calculation Hi, l would like to custom-made a toroidal power transformer because my old transformer broken. This power transformer is multi secondary output and center tapped winding (sec 1=0-9vac and sec 2= 71vac-0-71vac). Primary voltage is 230v with power rating @ 30va. The transformer dimension is 70mmx25mm. I'm not sure how to calculate the current ratings? If I want to change the power rating to 50va, what should be the current? Can someone help. Thanks. Rgrds/Roy3932
 28th August 2007, 04:25 AM #2 multi-volti   diyAudio Member     Join Date: May 2005 Location: Michigan Without knowing how much current each of the existing secondaries had to deliver, you can't know how the VA rating was shared by the multiple windings, only that increasing your VA rating will increase the proportional capacity of each of the windings in a higher rated xfmr. There may be some merit in picking apart the bad xfmr and measuring the diameter of the the magnet wire (not the external leads) for each secondary. From this we could estimate typical design current density used in xfmrs. (worst case 250-300 circular mils/A, conservatively perhaps 1000 CM/A). Regardless of what current density the designer assumed, we could estimate the load ratio between the two secondaries and work backward to determine currents. It would be an educated guess, perhaps better than having no info. Is there any way for you to estimate what each of the the windings has to accomplish? I wish I knew why it take 2-3 attempts for me to post. I'm always told I'm not logged in the first try. Murray __________________ Murray

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Holton Precision Audio         CSS         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post artquake Power Supplies 23 24th June 2008 09:41 AM cbutterworth Tubes / Valves 17 12th June 2008 10:54 PM cbutterworth Tubes / Valves 1 13th October 2006 04:42 AM kmtang Power Supplies 6 12th September 2006 06:44 AM JhonDoe Chip Amps 45 5th June 2004 01:11 AM

 New To Site? Need Help?

All times are GMT. The time now is 02:55 AM.