Litz Wire Selection
 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

 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
 22nd November 2009, 12:27 PM #1 microsim444   Account Disabled   Join Date: Oct 2008 Litz Wire Selection Hi All. I need some help selecting the proper LITZ wire, before I buy it. for my SMPS. Details. CORE: ETD59 FREQUENCY: 125KHZ OUTPUTS: SEC-1 85VAC 10A SEC-2 85VAC 10A SEC-3 20VAC 1A SEC-4 20VAC 1A SEC-5 16VAC 1A INPUT VOLTAGE:220v~ (360vdc) I saw one wire at e-bay litz wire 10/44, idont understant what is the 10/44. Anyway any help with selecting the proper wire is more than appreciated. Thanks...
 25th November 2009, 05:31 PM #2 Gopher   diyAudio Member   Join Date: Nov 2005 Location: UK I think the first number (10) is the American Wire Gauge and the second number is the number of insulated strands.
 25th November 2009, 09:28 PM #3 TechGuy   diyAudio Member   Join Date: Apr 2006 Location: Connecticut I found this chart useful for wire gauge vs frequency: American Wire Gauge table and AWG Electrical Current Load Limits with skin depth frequencies Here is a Skin effect Calculator: TRANSFORMERS At 125 Khz you need a wire diameter less than 26 gauge to cover 100% of a solid conductor. Of course heavier gauge wire will work, but you will have derate the current capacity. 10/44 means 10 parallel wires at 44 gauge. Which is probably too small for your output (16V @1A) since 40 gauge wire can only transport about 90 ma (44 is even lower). Another option is to wind your transformer using a several parallel enamel magnetic wires. A parallel set of two 28 gauge enamel magnetic wire should provide sufficient current capacity for your 20V and 16V outputs. For the 85V@10A, you need about 8 strands of 28 gauge wire. Generally I find I can only wind up to five parallel strains before its difficult to keep them flat and even (important when you transformer has multiple layers. You will probably need to wind two sets of 4 strand per layer to get all 8. You may be able to use4 strands of 24 gauge, but I can't find the equation or a skin effect calc you will provide the max. recommend current capacity for a given wire gauge and frequency. A 24 gauge copper wire can transport about 3.5 amps @ 68 Khz. My guess is that switching at 125 Khz would reduce the current capacity by about 20%. 4 * 2.8A = 11.2 Amps. FWIW: I would ditch the 16 V winding and use a simple switching regulator to provide the 16V output. This would make regulation easier. Its difficult to have good regulation with multiple outputs. I would even suggest two outputs 1 at 85V and the other at 24V and use two adjustable simple switchers to output 16V and 20V for tighter voltage regulation. This would greatly simply your transformer design. FYR: http://www.national.com/ds/LM/LM2576.pdf 3A-Step-down regulator.
 28th November 2009, 09:22 PM #4 microsim444   Account Disabled   Join Date: Oct 2008 Tech guy Please note that the 10/44 LITZ wire is 30AWG outer diameter!! Do you think if i get 20/44 will do the JOB??????
TechGuy
diyAudio Member

Join Date: Apr 2006
Location: Connecticut
Quote:
 Originally Posted by microsim444 Please note that the 10/44 LITZ wire is 30AWG outer diameter!! Do you think if i get 20/44 will do the JOB??????
Definately not for the 10A. if it was 20/40 (40 gauge) it would carry only 90ma*20 or 1.8 Amps. I don't know what the current capacity of 44 gauge wire but I bet is considerable less than 90 ma. The outer thickness is meaning less All that matters is how much copper is available to transport current. Litz 44 is used for very high frequency ( > 1 Mhz) switching. You don't need it, since your only switching at 125 Khz.

Why don't you read my entire earlier post and use my recommendation.

 2nd December 2009, 10:19 PM #6 microsim444   Account Disabled   Join Date: Oct 2008 Design I have already submitted my schematic and transformer specs, to the manufacturer, and its almost finished, so I am no longer worried about it any more, I am in the PCB design process, looking for a company who could do it. its designed to deliver +-100VDC 10AM, 10AMP at full load!! Its costly since its the first!

 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         Aussie Amplifiers         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 fazman Everything Else 126 20th June 2011 02:48 PM FrankDIY Everything Else 14 17th December 2009 05:12 PM Eva Class D 14 2nd July 2006 07:49 AM gearheaddruid Swap Meet 0 11th January 2005 05:07 AM ClassD Parts 0 5th April 2004 06:37 AM

 New To Site? Need Help?

All times are GMT. The time now is 06:04 AM.