[ARC5] Slightly OT: Transformers

[J. Forster]

Steel quality sets max flux density.

Circular mils is cross-section of copper in the windings, hence copper loss.

Generally transformers are designed so:\

Copper loss = core loss.

-John
=================



> Ratings vary from 500 to 1000 circular mills per amp depending upon the
> quality of the steel used. The 500 rating goes back to the 30's and was
> repeated for decades in the ARRL Handbook but in WW2 and later in consumer
> electronics materials improved.
>
> There was a posting somewhere of estimating the VA of a transformer by
> measuring the core but I cant find it right now.
>
> Carl
>
> ----- Original Message -----
> From: "Fuqua, Bill L" <wlfuqu00 at uky.edu>
> To: "Eric Mynes" <kc8wzb at gmail.com>; <ARC5 at mailman.qth.net>
> Sent: Wednesday, November 27, 2013 11:16 PM
> Subject: Re: [ARC5] Slightly OT: Transformers
>
>
>>  In the late 60's or 70's there was a multipage article in Electronics
>> Magazine on power  transformers
>> and how you can determine the rating of a transformer up to kW range.
>> The
>> magazine is gone now
>> but perhaps there is a URL that has the PDF of those magazines.
>> 73
>> Bill wa4lav
>>
>> ________________________________________
>> From: arc5-bounces at mailman.qth.net [arc5-bounces at mailman.qth.net] on
>> behalf of Eric Mynes [kc8wzb at gmail.com]
>> Sent: Wednesday, November 27, 2013 6:10 PM
>> To: ARC5 at mailman.qth.net
>> Subject: [ARC5] Slightly OT: Transformers
>>
>> Greetings all,
>>
>> I have some questions about transformers and this seems to be the only
>> group I'm in now that deals with tube rigs.  I hope you don't mind
>> elmering
>> me a bit by answering a few questions.  I mention slightly off topic
>> because one day (hopefully soon) I'll start building a power supply to
>> use
>> with my ARC 5 rigs, but for now, I just want to be able to power some
>> basic
>> homebrew tube transmitters.
>>
>> So, my questions go along the lines of...  I have several transformers
>> that
>> have followed me home from hamfests or someone has given me.  But most
>> are
>> not labeled in any fashion as to what they are rated for.  As stated
>> above,
>> I'd like to build a small power supply that can run some homebrew tube
>> rigs.  I might actually use some of the thousands of tubes that followed
>> me
>> home from hamfests instead of leaving them piled in boxes with no use.
>> I've tried googling any number or marking on the transformers trying to
>> find a manufacturer or specifications and haven't had any luck.  How can
>> I
>> test these safely as to not hurt myself or the transformer so that I
>> find
>> out at least the voltages I should expect out of them?  Right now, I'm
>> not
>> too concerned about finding how many amps they will provide as much as
>> now
>> much voltage is on the end of the wire.  The number of amps question
>> will
>> come soon though.
>>
>> Currently I have a transformer on my bench that has the following
>> markings
>> 110v004h82
>> 352052
>>
>> It appears to have 3 windings.  A black set (I presume is the primary),
>> a
>> red set with CT, and a green set with CT.
>>
>> I'm kind of skittish at just applying 110v to the black wires and seeing
>> what the others have for voltages.  So, I figure why not ask some hams
>> that
>> might have a better clue than me.
>>
>> Please respond to me off the list as I don't want to waste too much of
>> the
>> list's bandwidth on something that might be determined as an elementary
>> question that we all should know.  I'll be quick to say that I'm a very
>> much at an elementary stage on using HV and know enough to ask questions
>> before just trying things.
>>
>> Thank you for the bandwidth and Happy Thanksgiving to all
>>
>> 73,
>> Eric
>> k8ohz
>> ______________________________________________________________
>> ARC5 mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/arc5
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:ARC5 at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>> ______________________________________________________________
>> ARC5 mailing list
>> Home: http://mailman.qth.net/mailman/listinfo/arc5
>> Help: http://mailman.qth.net/mmfaq.htm
>> Post: mailto:ARC5 at mailman.qth.net
>>
>> This list hosted by: http://www.qsl.net
>> Please help support this email list: http://www.qsl.net/donate.html
>>
>>
>> -----
>> No virus found in this message.
>> Checked by AVG - www.avg.com
>> Version: 10.0.1432 / Virus Database: 3629/6372 - Release Date: 11/27/13
>>
>
> ______________________________________________________________
> ARC5 mailing list
> Home: http://mailman.qth.net/mailman/listinfo/arc5
> Help: http://mailman.qth.net/mmfaq.htm
> Post: mailto:ARC5 at mailman.qth.net
>
> This list hosted by: http://www.qsl.net
> Please help support this email list: http://www.qsl.net/donate.html
>
>