Is there a cheap source for buying transformer laminates? I would like
to build some transformers and would like to get decent efficiency
close to commercial transformers. The laminates should not cost more
than buying a commercial trans and should be much cheaper.  I would
like to try E and toroidal types. I could also punch my own laminates
if it is much cheaper to buy solid sheets instead.

In article <1...@x5g2000yqk.googlegroups.com>,
"B...@gmail.com" <b...@gmail.com> wrote:
>Is there a cheap source for buying transformer laminates? I would like
>to build some transformers and would like to get decent efficiency
>close to commercial transformers. The laminates should not cost more
>than buying a commercial trans and should be much cheaper.  I would
>like to try E and toroidal types. I could also punch my own laminates
>if it is much cheaper to buy solid sheets instead.

In another group I talked about going to a local transformer shop 
buying cheap copper wire and getting free mica tape and laminates.
But that was in the early 80's.
Laminates were large, 4 inch by almost 3 feet.

greg

In article <h2gdn5$e1l$1...@usenet01.srv.cis.pitt.edu>, z...@zekfrivolous.com (GregS) wrote:
>In article <1...@x5g2000yqk.googlegroups.com>,
> "B...@gmail.com" <b...@gmail.com> wrote:
>>Is there a cheap source for buying transformer laminates? I would like
>>to build some transformers and would like to get decent efficiency
>>close to commercial transformers. The laminates should not cost more
>>than buying a commercial trans and should be much cheaper.  I would
>>like to try E and toroidal types. I could also punch my own laminates
>>if it is much cheaper to buy solid sheets instead.
>
>In another group I talked about going to a local transformer shop 
>buying cheap copper wire and getting free mica tape and laminates.
>But that was in the early 80's.
>Laminates were large, 4 inch by almost 3 feet.

I keep pushing these things around, always getting in the way.

greg

On Wed, 1 Jul 2009 12:20:31 -0700 (PDT), "B...@gmail.com"
<b...@gmail.com> wrote:

>Is there a cheap source for buying transformer laminates? I would like
>to build some transformers and would like to get decent efficiency
>close to commercial transformers. The laminates should not cost more
>than buying a commercial trans and should be much cheaper.  I would
>like to try E and toroidal types. I could also punch my own laminates
>if it is much cheaper to buy solid sheets instead.

Lamination materials are inexpensive only when purchased in volume,
justifying paperwork, handling and shipping costs. This is true with
most materials and should be no surprise.

Transformer manufacturers will typically purchase grades of stock in
large rolls, by the skid, truck or box-car load, with inventory and
stamping/slitting tooling costs being averaged over long-term use. As
the tools age, productivity will reduce and the quality of their
output may degrade. Obtaining flat, burr-free stampings from
low-volume methods is not an elementary exercise.

You might obtain unvarnished laminated stock from distribution or
surplus outlets in sample quantities; they are sold by weight.

http://www.dawntechnologiesltd.com/index.htm
http://www.thomas-skinner.com/
http://www.magmet.com/

It used to be the rule that heavy articles could be competitive when
produced locally, resulting in local sources for 60Hz magnetics and
materials. This is no longer true. What 'should be' may be irrelevant.

Frankly, it's a lot cheaper to 'iterate' on paper first, or through
the use of various public domain spreadsheets or software. The
efficiency of the part will benefit most from this exercise and your
understanding of the practical limitations of the materials and
methods involved.

Evaluation samples of preassembled magnetics, to your design
specification, can be requested in the unvarnished state from most
custom vendors, if you want to fiddle with similar iterations using
those materials.

This skill is not particularly highly valued in the industry, at lower
power levels.

RL

Try Temple Steel, I recently purchased approx $100 of laminations as a 
small qty. They were very helpful.

Cheers


"B...@gmail.com" <b...@gmail.com> wrote in message 
news:1...@x5g2000yqk.googlegroups.com...
> Is there a cheap source for buying transformer laminates? I would like
> to build some transformers and would like to get decent efficiency
> close to commercial transformers. The laminates should not cost more
> than buying a commercial trans and should be much cheaper.  I would
> like to try E and toroidal types. I could also punch my own laminates
> if it is much cheaper to buy solid sheets instead. 

On Jul 1, 5:14=A0pm, "Martin Riddle" <martin_...@verizon.net> wrote:
> Try Temple Steel, I recently purchased approx $100 of laminations as a
> small qty. They were very helpful.
>
> Cheers
>


how much was the small quantity? Hopefully large enough to make a few
decent sized transformers(25W or more). Would you care to tell me
which ones you got and about how many?

http://www.tempel.com/products.asp?region=3D1

Thanks

"B...@gmail.com" <b...@gmail.com> wrote in message 
news:b...@q14g2000vbn.googlegroups.com...
> On Jul 1, 5:14 pm, "Martin Riddle" <martin_...@verizon.net> wrote:
>> Try Temple Steel, I recently purchased approx $100 of laminations as 
>> a
>> small qty. They were very helpful.
>>
>> Cheers
>>
>
>
> how much was the small quantity? Hopefully large enough to make a few
> decent sized transformers(25W or more). Would you care to tell me
> which ones you got and about how many?
>
> http://www.tempel.com/products.asp?region=1
>
> Thanks

These were for a 300w transformer 
<http://www.tempel.com/products.asp?id=165>;
E137H/0136  1 String (28lbs) of M6 grade 29awg was 1.79/lb , I believe 
it was $100 total with shipping.
Got 4 or 5 transformers out of it.  The thinner laminations were 1.3/lb 
and 1.0/lb

The string size depends on the lamination size, So I picked the 
laminations by a minimum string size.  The sales rep was very helpful. 
Email me if you run into a non helpful rep, and I'll give you the rep I 
had dealt with.
You can try other vendors, they still may be trying to recover commodity 
prices for the steel they purchased when it was high.
Also, I would think that the smaller EI cores would have larger string 
sizes. Some strings were 500lbs. The 137H was one of the  popular 
laminations.

Hope that helps. 

"B...@gmail.com" <b...@gmail.com> wrote in message 
news:b...@q14g2000vbn.googlegroups.com...
> On Jul 1, 5:14 pm, "Martin Riddle" <martin_...@verizon.net> wrote:
>> Try Temple Steel, I recently purchased approx $100 of laminations as 
>> a
>> small qty. They were very helpful.
>>
>> Cheers
>>
>
>
> how much was the small quantity? Hopefully large enough to make a few
> decent sized transformers(25W or more). Would you care to tell me
> which ones you got and about how many?
>
> http://www.tempel.com/products.asp?region=1
>
> Thanks
 

"B...@gmail.com" <b...@gmail.com> wrote in message 
news:b...@q14g2000vbn.googlegroups.com...
> On Jul 1, 5:14 pm, "Martin Riddle" <martin_...@verizon.net> wrote:
>> Try Temple Steel, I recently purchased approx $100 of laminations as 
>> a
>> small qty. They were very helpful.
>>
>> Cheers
>>
>
>
> how much was the small quantity? Hopefully large enough to make a few
> decent sized transformers(25W or more). Would you care to tell me
> which ones you got and about how many?
>
> http://www.tempel.com/products.asp?region=1
>
> Thanks

These were for a 300w transformer
<http://www.tempel.com/products.asp?id=165>;
E137H/0136  1 String (28lbs) of M6 grade 29awg was 1.79/lb , I believe
it was $100 total with shipping.
Got 4 or 5 transformers out of it.  The thinner laminations were 1.3/lb
and 1.0/lb

The string size depends on the lamination size, So I picked the
laminations by a minimum string size.  The sales rep was very helpful.
Email me if you run into a non helpful rep, and I'll give you the rep I
had dealt with.
You can try other vendors, they still may be trying to recover commodity
prices for the steel they purchased when it was high.
Also, I would think that the smaller EI cores would have larger string
sizes. Some strings were 500lbs. The 137H was one of the  popular
laminations.

Hope that helps.
 

On Wed, 1 Jul 2009 12:20:31 -0700 (PDT), "B...@gmail.com"
<b...@gmail.com> wrote:

>Is there a cheap source for buying transformer laminates? I would like
>to build some transformers and would like to get decent efficiency
>close to commercial transformers. The laminates should not cost more
>than buying a commercial trans and should be much cheaper.  I would
>like to try E and toroidal types. I could also punch my own laminates
>if it is much cheaper to buy solid sheets instead.


  You are far better off buying a transformer that is of the frequency
and VA rating that your target application is, and remove the transformer
windings, and then apply your own.

  THAT is, by far, the cheaper method, as without compressive lamination
bonding, you are going to have efficiency variances.

  By using an existing transformer, you are using an already matched set
of plates, and typically get a bobbin in the deal for free.

  If you unwind it carefully, you may find one winding that matches your
target.  Not always, and winding your specific need is best, of course,
but it does happen at times.