Hi All;
I would be most interested in any of the articles sent to my email address > kimbalsummers@hotmail.com < or at least the web links for downloading them :-
The Use of Audio Frequncy Transformers -
Book - Crowhurst - Audio Handbook #3 - 66pp. 1953
Excellent overall book on Audio Transformers. Rare.
Input Transformer Design -
Article - Crowhurst - 11pp Audio Engineering Mag. June - July 56
This is Crowhurst at his best !! EXCELLENT ARTICLE !!
Remember Crowhurst was the guy who supplied the design
charts given in the Radiotron Handbook - large 4th edition.
Output Transformer Design -
Article - Crowhurst - 7pp. Audio Enginnering Mag. Sept 56
Once again a SUPERB Crowhurst gem of an article.
Excellent information!
Audio Transformer Design -
Article - Crowhurst - 4pp. Audio Engineering Mag. Feb 53
More Excellent Crowhurst !
Measuring Up an Audio Transformer -
Article - Crowhurst - 4pp. Audio Engineering Mag. Nov 52
Excellent article.
Electrical Adjustment in Fitting a New Output Transformer -
Article - Crowhurst - 5pp. Glass Audio 2-92
Recent Crowhurst always informative.
Audio Transformers Can Be Good -
Article - Crowhurst - 5pp. Audio Engineering Mag. May 56
One of Crowhurst's best, very informative.
How An Output Transformer Causes Distortion -
Article - Crowhurst - 7pp. Audio Engineering Mag. Feb-Mar 57
Another great Crowhurst article in two parts !
Using the Reactance Chart -
Article - H. B. Davis 3pp. Audio Engineering Mag. Dec 49
Quick how to guide for filter design.
Winding Your Own Single Ended Output Transformer -
Article - Jim Flowers - 34pp. Valve Magazine 1997
Excellent, detailed and well written ! Article is in 4 parts.
Transformer Design for Zero Impedance Amplifiers -
Article - Grossner - 5pp. Audio Engineering Mag. Mar 56
Very good article.
Harmonic Distortion in Iron Core Transformers -
Article - Williams, Eastop - 4pp. Audio Engineering Mag. April 51
Very good and hard to find article.
A New 50 Watt Amplifier Circuit ( McIntosh) -
Article - Frank McIntosh - 6pp. Audio Engineering Mag. Dec 59
Yes, the Unity famous Unity Coupled transformer is well covered!
Output Transformer Impedance Matching -
Article - R. Tomer - 1pp. Radio News
Interesting little simplified design chart.
Output Transformers -
Article - James Moir - 9pp. Glass Audio 94
In Depth Output Transformer design and construction !!
Two part article. Reprinted from Audio Engineering, Feb 60
Output Transformers -
Article - James Moir - 9pp. Audio Engineering Mag. Feb 60
This is the original version of this article as it
appeared in Audio Engineering Magazine.
Practical Transformer Design and Construction -
Article - C. Roeschke - 12pp. Radio News 1947
Rare, rare, rare !! Three part article. Practical transformer construction guide.
Optimum Use of Nickel Alloy Steels in Low Level Transformers -
Article - L. Howard - 2pp. Audio Engineering Mag. Oct 50
Interesting guide to shielding transformers.
Output Transformer Design Considerations -
Article - Ayres - 2pp. Audio Engineering Mag. April 53
Quick and easy read.
Transformer Applications -
Article - Ayres - 3pp. Audio Engineering Mag. Nov 49
Another quick read regarding impedance calculations.
Feedback from Output Transformer Secondary -
Article - Ayres - 2pp. Audio Engineering Mag. July 53
A quick overview of this technique.
Transformers -
Article - Arnold Schwartz - 4pp. db Magazine 1973
Good little audio transformer primer.
New Transformer Design for Power Amplifiers -
Article - C. Graham (Faichild) - 4pp. Radio & TV News Nov 56
Design details of the Fairchild 275 Amplifier Output Transformer.
Transformer Distortion -
Article - Dunford Kelly 5pp. - Audio Engineering Mag. Mar 59
Very good article in 2 parts.
Coils, Cores, and Magnets -
Article - Schendel- 7pp. Radio Craft 1946
Excellent diy coil winding info from the
years when some of the best trannies were made.
Determining Unknown Impedances in Transformers -
Article - L. Hippe - 2pp. Audio Engineering Mag. 1950
Handy information here.
Making Custom Transformers -
Article - H. Strand - 9pp. Science and Mechanics Magazine 1960
It's in 2 parts and serves as a good diy and core salvage info here.
Windings -
Chapter, sec. 3 - Annon - 12pp. Web find - Coilwinding
Some useful info here.
Transformer and Inductor Design Manual -
Booklet - Magnetics Technology Center - 39pp.
There is a version of this on the web but this
is a much cleaner scan. It's a handy guide.
Transformer Design & Manuafcturing Manual 1984 -
Book - R. Wolpert 130 pages. Out of Print
Very practical treatment of the whole subject.
Very hands on. This one is out of print but used to be available.
Coil Winding -
Book - Geo.Stevens Manufacturing - 1st ed. in 1954 & 2nd ed. 1958.
Practical how to coil winding book.
Transformers -
Book - Rider Publication No. 166-37 92pp.
Semi-famous and quite rare Rider Transformers book.
Great information.
Wideband Subminiature Transformers -
Article - Steven Temmer - 4pp. db Magazine 1973
Beyer Audio Transformer Design info.
Beyer Audio Transformer Catalog -
Catalog - 19 pp. Very Rare and informative.
Wireless Coils, Chokes, and Transformers -
Book - 185 pp. F. J. Camm - Standard reference
on diy coils and transformers. Good information.
High Quality Communication and Power Transformers -
Superb Paper - E. B. Harrison (Altec Hollywood Years) 12pp.
This is a paper from the Motion Picture Society Journal and it is
an Excellent Paper!! A Must Read !!
Electronic Design Charts -
Book - N. Crowhurst-Gernsback - 1963 -128pp.
Very cool and rare book of design charts for
inductors and transformers. Very handy!!
If any one has any of the above and other intersting stuff on Audio/ Power Transformer design, I would appreciate hearing about it.
Cheers !
I would be most interested in any of the articles sent to my email address > kimbalsummers@hotmail.com < or at least the web links for downloading them :-
The Use of Audio Frequncy Transformers -
Book - Crowhurst - Audio Handbook #3 - 66pp. 1953
Excellent overall book on Audio Transformers. Rare.
Input Transformer Design -
Article - Crowhurst - 11pp Audio Engineering Mag. June - July 56
This is Crowhurst at his best !! EXCELLENT ARTICLE !!
Remember Crowhurst was the guy who supplied the design
charts given in the Radiotron Handbook - large 4th edition.
Output Transformer Design -
Article - Crowhurst - 7pp. Audio Enginnering Mag. Sept 56
Once again a SUPERB Crowhurst gem of an article.
Excellent information!
Audio Transformer Design -
Article - Crowhurst - 4pp. Audio Engineering Mag. Feb 53
More Excellent Crowhurst !
Measuring Up an Audio Transformer -
Article - Crowhurst - 4pp. Audio Engineering Mag. Nov 52
Excellent article.
Electrical Adjustment in Fitting a New Output Transformer -
Article - Crowhurst - 5pp. Glass Audio 2-92
Recent Crowhurst always informative.
Audio Transformers Can Be Good -
Article - Crowhurst - 5pp. Audio Engineering Mag. May 56
One of Crowhurst's best, very informative.
How An Output Transformer Causes Distortion -
Article - Crowhurst - 7pp. Audio Engineering Mag. Feb-Mar 57
Another great Crowhurst article in two parts !
Using the Reactance Chart -
Article - H. B. Davis 3pp. Audio Engineering Mag. Dec 49
Quick how to guide for filter design.
Winding Your Own Single Ended Output Transformer -
Article - Jim Flowers - 34pp. Valve Magazine 1997
Excellent, detailed and well written ! Article is in 4 parts.
Transformer Design for Zero Impedance Amplifiers -
Article - Grossner - 5pp. Audio Engineering Mag. Mar 56
Very good article.
Harmonic Distortion in Iron Core Transformers -
Article - Williams, Eastop - 4pp. Audio Engineering Mag. April 51
Very good and hard to find article.
A New 50 Watt Amplifier Circuit ( McIntosh) -
Article - Frank McIntosh - 6pp. Audio Engineering Mag. Dec 59
Yes, the Unity famous Unity Coupled transformer is well covered!
Output Transformer Impedance Matching -
Article - R. Tomer - 1pp. Radio News
Interesting little simplified design chart.
Output Transformers -
Article - James Moir - 9pp. Glass Audio 94
In Depth Output Transformer design and construction !!
Two part article. Reprinted from Audio Engineering, Feb 60
Output Transformers -
Article - James Moir - 9pp. Audio Engineering Mag. Feb 60
This is the original version of this article as it
appeared in Audio Engineering Magazine.
Practical Transformer Design and Construction -
Article - C. Roeschke - 12pp. Radio News 1947
Rare, rare, rare !! Three part article. Practical transformer construction guide.
Optimum Use of Nickel Alloy Steels in Low Level Transformers -
Article - L. Howard - 2pp. Audio Engineering Mag. Oct 50
Interesting guide to shielding transformers.
Output Transformer Design Considerations -
Article - Ayres - 2pp. Audio Engineering Mag. April 53
Quick and easy read.
Transformer Applications -
Article - Ayres - 3pp. Audio Engineering Mag. Nov 49
Another quick read regarding impedance calculations.
Feedback from Output Transformer Secondary -
Article - Ayres - 2pp. Audio Engineering Mag. July 53
A quick overview of this technique.
Transformers -
Article - Arnold Schwartz - 4pp. db Magazine 1973
Good little audio transformer primer.
New Transformer Design for Power Amplifiers -
Article - C. Graham (Faichild) - 4pp. Radio & TV News Nov 56
Design details of the Fairchild 275 Amplifier Output Transformer.
Transformer Distortion -
Article - Dunford Kelly 5pp. - Audio Engineering Mag. Mar 59
Very good article in 2 parts.
Coils, Cores, and Magnets -
Article - Schendel- 7pp. Radio Craft 1946
Excellent diy coil winding info from the
years when some of the best trannies were made.
Determining Unknown Impedances in Transformers -
Article - L. Hippe - 2pp. Audio Engineering Mag. 1950
Handy information here.
Making Custom Transformers -
Article - H. Strand - 9pp. Science and Mechanics Magazine 1960
It's in 2 parts and serves as a good diy and core salvage info here.
Windings -
Chapter, sec. 3 - Annon - 12pp. Web find - Coilwinding
Some useful info here.
Transformer and Inductor Design Manual -
Booklet - Magnetics Technology Center - 39pp.
There is a version of this on the web but this
is a much cleaner scan. It's a handy guide.
Transformer Design & Manuafcturing Manual 1984 -
Book - R. Wolpert 130 pages. Out of Print
Very practical treatment of the whole subject.
Very hands on. This one is out of print but used to be available.
Coil Winding -
Book - Geo.Stevens Manufacturing - 1st ed. in 1954 & 2nd ed. 1958.
Practical how to coil winding book.
Transformers -
Book - Rider Publication No. 166-37 92pp.
Semi-famous and quite rare Rider Transformers book.
Great information.
Wideband Subminiature Transformers -
Article - Steven Temmer - 4pp. db Magazine 1973
Beyer Audio Transformer Design info.
Beyer Audio Transformer Catalog -
Catalog - 19 pp. Very Rare and informative.
Wireless Coils, Chokes, and Transformers -
Book - 185 pp. F. J. Camm - Standard reference
on diy coils and transformers. Good information.
High Quality Communication and Power Transformers -
Superb Paper - E. B. Harrison (Altec Hollywood Years) 12pp.
This is a paper from the Motion Picture Society Journal and it is
an Excellent Paper!! A Must Read !!
Electronic Design Charts -
Book - N. Crowhurst-Gernsback - 1963 -128pp.
Very cool and rare book of design charts for
inductors and transformers. Very handy!!
If any one has any of the above and other intersting stuff on Audio/ Power Transformer design, I would appreciate hearing about it.
Cheers !
I scanned the McIntosh article long ago - it's on my web page: http://www.audiophool.cjb.net/Techno.html
I have a good few of those in hard copy, problem is, I haven't a scanner, and I have many schematics I am dying to share with the web, and I can't upload them for the same reason and hosting.
if anyone can help, I would be dellighted to give them the schematics to upload/host, but I am in england
there are MANY commercial worthwhile, its my dream to get them to the public.
if anyone can help, I would be dellighted to give them the schematics to upload/host, but I am in england
there are MANY commercial worthwhile, its my dream to get them to the public.
Thanks for your assistant eveyone.
I will look at the above link and see what I need. I'm like most people and copy as much as I can find because many links die out after a few years and the information is no longer available.
As for the 'It cdr Data' I suggest you find a friend who has a scanner on the web, or scan it onto a CD or a USB memory stick.
Alternatively if you can give me an idea of postage cost to send it to my address in Australia (Queensland,4573 post code), I would be willing to do it for you as I have a PDF scanner and the time to do it; but I can totally understand your reluctance to not let the material out of your posession. ( See my email address at the bottom of this post should you go down this path. )
Alternatively find some one on the forums in your own country who you can work with the scan the stuff. The longer its left off the more frustrating it will be for all. Procrastination gets one nowhere.
I'm seriously toying with the idea of making a central website totally devoted to Audio/ power transformer design notes and 'how to' info. There is nothing available, but more and more people are wanting access to the material. Unfortunately the realy good design stuff costs money most cannot afford, because it's copyrighted or you have to sign up to some University-research library or pay for each document you download from IEEE or AES websites; etc.
The material is out there it's just getting it all together in place.
Kimbal
I will look at the above link and see what I need. I'm like most people and copy as much as I can find because many links die out after a few years and the information is no longer available.
As for the 'It cdr Data' I suggest you find a friend who has a scanner on the web, or scan it onto a CD or a USB memory stick.
Alternatively if you can give me an idea of postage cost to send it to my address in Australia (Queensland,4573 post code), I would be willing to do it for you as I have a PDF scanner and the time to do it; but I can totally understand your reluctance to not let the material out of your posession. ( See my email address at the bottom of this post should you go down this path. )
Alternatively find some one on the forums in your own country who you can work with the scan the stuff. The longer its left off the more frustrating it will be for all. Procrastination gets one nowhere.
I'm seriously toying with the idea of making a central website totally devoted to Audio/ power transformer design notes and 'how to' info. There is nothing available, but more and more people are wanting access to the material. Unfortunately the realy good design stuff costs money most cannot afford, because it's copyrighted or you have to sign up to some University-research library or pay for each document you download from IEEE or AES websites; etc.
The material is out there it's just getting it all together in place.
Kimbal
Have a look over Pete's site..
http://www.pmillett.com/technical_books_online.htm
Lots of good stuff!
You can even send him (sacrificial) books to be scanned.
http://www.pmillett.com/technical_books_online.htm
Lots of good stuff!
You can even send him (sacrificial) books to be scanned.
DigitalJunkie said:Have a look over Pete's site..
http://www.pmillett.com/technical_books_online.htm
Lots of good stuff!
You can even send him (sacrificial) books to be scanned.
Thanks for the link but I have had the whole Pete Millet site downloaded for sometime. Alas there is very little on it about audio transformers, even Pete has told me in his emails he has very little on the subject - just the same old references we all have like the Radiotron Designer's Handbook and a few bits and pieces of Crowhursts more popular audio articles.
I'm seeking some of the harder to get references, such as what I listed at the beginning of the thread.
Basically If I don't have it, it's very unlikely others will - but I will still ask just the same.
DigitalJunkie said:Have a look over Pete's site..
http://www.pmillett.com/technical_books_online.htm
Lots of good stuff!
You can even send him (sacrificial) books to be scanned.
OMG, u have given me the nightmare of becoming a school children again.
lt cdr data said:
I have HP scanner in office with feed system which can scan (with somewhat mediocre quality) any paper material (non-binded and non-jammed). Its not a problem for me to scan all that stuff if it can be feed in this scanner. Additionally, I have very good HP scanner at home, but without auto-feeder.
Please take a hi-res photo of your material (on table), and e-mail me to ANDREI - at - STARLETT - dot - LV
I'll look what can be done. Additionally, I have 100 - 150 GB of webspace for hosting this data. However, this is my company site, so only public domain articles/books can be uploaded, NO copyright protected material at all.
Just to mention, the often quoted relevant section in Radio Designer's Handbook use the graphs originally compiled by Norman Crowhurst. There also exists a computer program based on the same information.
I have used the Crowhurst design procedures and charts for the past 50 years and always found them close to reality. One does make certain allowances with time (e.g. how close the leakage impedance is to the calculated value depends on how 'tight' the layers are to one another - there is always air space.) Then I compress in the direction of the core 'legs'. Folks frown at this predicting damage to windings; one does of course not mean compressing the smoke out of them - but the space does exist, and it makes for a smaller spread in leakage values.
Etc. - not to make a tutorial out of this. These days I mostly wind my own transformers after some disappointment with commercial transformer businesses. It also cuts the cost. It is a time-consuming operation, but which I have for free, being retired.
I have used the Crowhurst design procedures and charts for the past 50 years and always found them close to reality. One does make certain allowances with time (e.g. how close the leakage impedance is to the calculated value depends on how 'tight' the layers are to one another - there is always air space.) Then I compress in the direction of the core 'legs'. Folks frown at this predicting damage to windings; one does of course not mean compressing the smoke out of them - but the space does exist, and it makes for a smaller spread in leakage values.
Etc. - not to make a tutorial out of this. These days I mostly wind my own transformers after some disappointment with commercial transformer businesses. It also cuts the cost. It is a time-consuming operation, but which I have for free, being retired.
I have a Fujitsu scanner that can scan 25 double sided pages a minute and would be happy to do the scanning. My wife will be travelling to England (Sheffield) in July and she can bring it back to me in Aug to scan if that works. Unfortunately, I cannot host the material except perhaps on Google drive.
To be honest... These articles are not going to help someone be a good transformer designer.... I am very familiar with most of the listed articles... If you truly want to design transformers you must study and have a deep understanding of the physics and math behind the operation of a transformer... At least understand Maxwell's equation and how to derive equations from it... A lot of these articles have charts that are based off of the classic equations with some fudge factors added in from the author... Many of the steels are no longer made and do not apply... These articles only touch the tip of the surface ...
A few good textbooks to learn from would be:
1. Magnetic Circuits and Transformers.... MIT STAFF
2. Transformer Engineering ....Blume
3. Inductance Calculations..... Grover
http://dl.icdst.org/pdfs/files/fb34a8223c18fee37fa1810e3583a0de.pdf
http://verimod.com/pdf_files/Transformer_Engineering-Rogowski_Leakage.pdf
A few good textbooks to learn from would be:
1. Magnetic Circuits and Transformers.... MIT STAFF
2. Transformer Engineering ....Blume
3. Inductance Calculations..... Grover
http://dl.icdst.org/pdfs/files/fb34a8223c18fee37fa1810e3583a0de.pdf
http://verimod.com/pdf_files/Transformer_Engineering-Rogowski_Leakage.pdf
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