SMPS Ferrite Core from UK

[MAXPAYNE]

I need to know some SMPS tx ferrite core model from Farnell UK/ Rs Online UK. I wanna use them for building 200W-700W DC power supply and 500W-4000W sine wave inverter.

Pls suggest me appropriate part no...

[Faros]

Go to CoilCraft Design Support Tools @

http://www.coilcraft.com/design_tools.cfm

then cross-match your findings with Farnell, they have recently raised their stock from CoilCraft to 6000+  parts.        

[MAXPAYNE]

Go to CoilCraft Design Support Tools @

http://www.coilcraft.com/design_tools.cfm

then cross-match your findings with Farnell, they have recently raised their stock from CoilCraft to 6000+  parts.        

They are for inductor and flyback trafo only !

I need core for push-pull, half-bridge and full bridge topology ...

[Faros]

I see, if I were in your shoes I would have searched in local suppliers (usually not on the web) or (for prototyping purposes) you can search an old SMPS transformer and extract its core, both ways you have to be geared for winding. 

[Gallymimu]

Faros, he needs pretty big cores for the power, though, coilcraft might be okay for the smaller power project he was talking about.

Maxpayne, you are asking a very vague question and are basically asking someone to design it for you and give you a part number.  You need to design your magnetics first (winding area, max flux density, frequency, core loss).  At least you need a rough idea of these things.

Here is a list of bigger cores you might consider of various materials:

http://www.newark.com/jsp/search/browse.jsp?N=422+2203+215109+810493164+810493286+810493440+810345594+810493574+810463462+810493017+810345513+810345554+810456674+810457034+810456686+810493160+810492876+810493004+810352116+810493422+810493029+810456995+810456842+810463216+810456679+810456727+810456688&No=25&Ntk=gensearch&Ntt=ferrite+core&Ntx=mode+matchallpartial&locale=en_US&appliedparametrics=true&getResults=true&originalQueryURL=/jsp/search/browse.jsp%3FN%3D422%2B2203%2B215109%26Ntk%3Dgensearch%26Ntt%3Dferrite%2Bcore%26Ntx%3Dmode%2Bmatchallpartial%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_US%26divisionLocale%3Den_US%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D422%2B2203%2B215109

I'd look closely at the UR64 cores in a 3F3 3C90 or 3C95 material.  They are cheap and easy to work with for the amount of ferrite you get with them.  These are what we often use in multi KW supplies.  You can also parallel cores to get bigger powers (which you don't need for your application).

go to the ferroxcube website and learn about what it means to pick core materials and core sizes.  Learn to design your transformers.  We can be more helpful with specific questions.

[MAXPAYNE]

I see, if I were in your shoes I would have searched in local suppliers (usually not on the web) or (for prototyping purposes) you can search an old SMPS transformer and extract its core, both ways you have to be geared for winding. 

I see, if I were in your shoes I would have searched in local suppliers (usually not on the web) or (for prototyping purposes) you can search an old SMPS transformer and extract its core, both ways you have to be geared for winding. 

I normally do that for hobby purpose, scavenging them from old smps. I have a plan for going to commercial design. so, I have to r&d using known core parameter, which is not possible using scavenged core.

Posted on: March 19, 2013, 01:24:10 am - Automerged

Faros, he needs pretty big cores for the power, though, coilcraft might be okay for the smaller power project he was talking about.

Maxpayne, you are asking a very vague question and are basically asking someone to design it for you and give you a part number.  You need to design your magnetics first (winding area, max flux density, frequency, core loss).  At least you need a rough idea of these things.

Here is a list of bigger cores you might consider of various materials:

http://www.newark.com/jsp/search/browse.jsp?N=422+2203+215109+810493164+810493286+810493440+810345594+810493574+810463462+810493017+810345513+810345554+810456674+810457034+810456686+810493160+810492876+810493004+810352116+810493422+810493029+810456995+810456842+810463216+810456679+810456727+810456688&No=25&Ntk=gensearch&Ntt=ferrite+core&Ntx=mode+matchallpartial&locale=en_US&appliedparametrics=true&getResults=true&originalQueryURL=/jsp/search/browse.jsp%3FN%3D422%2B2203%2B215109%26Ntk%3Dgensearch%26Ntt%3Dferrite%2Bcore%26Ntx%3Dmode%2Bmatchallpartial%26No%3D0%26getResults%3Dtrue%26appliedparametrics%3Dtrue%26locale%3Den_US%26divisionLocale%3Den_US%26catalogId%3D%26skipManufacturer%3Dfalse%26skipParametricAttributeId%3D%26prevNValues%3D422%2B2203%2B215109

I'd look closely at the UR64 cores in a 3F3 3C90 or 3C95 material.  They are cheap and easy to work with for the amount of ferrite you get with them.  These are what we often use in multi KW supplies.  You can also parallel cores to get bigger powers (which you don't need for your application).

go to the ferroxcube website and learn about what it means to pick core materials and core sizes.  Learn to design your transformers.  We can be more helpful with specific questions.

I want to know which material core and what size I have to choose, parameters while choosing core etc. Can you suggest from where should I start ?

[Gallymimu]

Try starting here:


http://www.gotopower.net/article.asp?art_id=65
http://www.irf.com/technical-info/appnotes/an-1024.pdf

really all I did was google "smps flyback transformer design"

You need to pick a frequency,
then you need to determine the maximum primary voltage on your transformer
from this you can determine the max applied volt seconds applied to the transformer
then you need to balance the max flux density vs the primary turns on your transformer
there's more but that is the basic approach.  the design of the transformer is somewhat iterative as you balance max flux, windings, cross sectional area, and winding area.  You can't really go wrong with a BIG core to start with.

I don't usually do flybacks so you'll have to do some reading.  I think you need a decent air gap in a flyback for energy storage.  So you will probably have to put a spacer in between the cores.

[MAXPAYNE]

Try starting here:


http://www.gotopower.net/article.asp?art_id=65
http://www.irf.com/technical-info/appnotes/an-1024.pdf

really all I did was google "smps flyback transformer design"

You need to pick a frequency,
then you need to determine the maximum primary voltage on your transformer
from this you can determine the max applied volt seconds applied to the transformer
then you need to balance the max flux density vs the primary turns on your transformer
there's more but that is the basic approach.  the design of the transformer is somewhat iterative as you balance max flux, windings, cross sectional area, and winding area.  You can't really go wrong with a BIG core to start with.

I don't usually do flybacks so you'll have to do some reading.  I think you need a decent air gap in a flyback for energy storage.  So you will probably have to put a spacer in between the cores.

I need to study about core selection not for flyback but for push-pull, half-bridge and full bridge topology ...

[Gallymimu]

Core design is almost the same for all the topologies and is easier for the ones you need (sorry I said flyback I read your response to feros wrong).

http://www.diysmps.com/forums/showthread.php?275-SMPS-transformer-design-tool
http://www.digikey.com/Web%20Export/Supplier%20Content/Wurth_732/PDF/Wurth_CookbookforTransformerDesign.pdf?redirected=1

[MAXPAYNE]

What is the best and cheapest place to buy ferrite smps core from UK ?

[Tanuki]

Ferrite cores are not carried by most electronics distributors.  So buying them locally in prototype quantities is unlikely, regardless of where you're located.

There are several vendors on eBay that have pretty good selections.

BTW, Magnetic design is demanding, in your shoes I'd follow someone else's reference design. Otherwise you might have a bad experience.

[Gallymimu]

Buy from Farnell, I'm actually surprised that they carry what they do.

Posted on: March 23, 2013, 03:15:49 03:15 - Automerged
As far as demanding.  I disagree.  Unless you are trying to break records or really optimize your design you get usually make things work with a slightly oversized core and slightly larger than needed wire.  As long as you are staying away from resonant converters that rely on goofy things like high leakage inductance as part of the resonant circuit... most thing's aren't that hard.