Transformers: The Magnetic Circuit - Online Book

Vladmir Karapotpff    St Petersberg>Westinghouse>Cornell Prof. EE

1911  Lots of armature stuff but not a lot on transformers but still interesting

will put it in the Transformer Meta


https://babel.hathitrust.org/cgi/pt?id=mdp.39015006056918;view=1up;seq=1;size=150

or

https://books.google.com/books?id=9itPAAAAMAAJ&pg=PA255&lpg=PA255&dq=Vladimir++Karapetoff+transformer+air+gap&source=bl&ots=8puw_uKOAo&sig=ACfU3U0ob1QXLCH7uIWhu7aObETiPAqeoA&hl=en&sa=X&ved=2ahUKEwjH1eTAjIjgAhUTJjQIHf7dBGoQ6AEwC3oECAcQAQ#v=onepage&q=Vladimir%20%20Karapetoff%20transformer%20air%20gap&f=true

Those of a certain age will know Terman.

use to spend a lot of time at the Terman Library at Stanford, they had free access to the AES  server, and a lot of transformer books,  sadly during that time they were hauling out all the master thesis books and putting them into storage, they took up a lot of floor space and nobody was reading them much, too heavy i guess.

the graphical solution for the optimum air gap was developed by Karapotpff, which is seen in RDH4 and Grossman's book.

Just came across this.....

It's in German text though...

Nf‐Ausgangsübertrager für Röhren‐Endstufen

CJ... not sure where to put this, but you will know.

https://www.americanradiohistory.com/Archive-Wireless-World/40s/Wireless-World-1948-01.pdf 

Page 6 of PDF, Baxandall argues that a correctly laid-out tertiary winding makes amplifier NFB stability somewhat independent of loading, showing that the leakage inductances can be balanced as a wYe.

This is referenced in an interview, AA 4 1979.
https://www.americanradiohistory.com/Archive-Amateur-Audio/Audio-Amateur-1979-4.pdf

thanks for the cool articles! i will stick them in the xfmr meta! 

What an tremendous collection of documents PRR , thanks ,

I cant seem to find the second half of the interview with PJB in Audio amateur though

Interesting about AD Blumlien working at the same establishment as him  although deceased before Peters arrival .

The idea of the headphones with steerable sound or accelerometers to measure the position of the head and then feed the appropriate mix of stereo source signals sounds interesting , DSP of course had barely been born at that stage ,but the thing he suggests would certainly be doable in software now .

I did have a chance ,years ago, to try dummy head or binaural stereo , I got reasonably good results with a rectangular cardboard box as a head . The effect I found was that the eyes spoiled the illusion created by the headphones , I was listening from the control room and my ears were emersed in the soundfield of the room next door it creates a kind of disparity that the ears eyes and brain isnt used to in nature , I have to say I didnt get the full immersion effect without closing my eyes .

I think I remember reading about tertiary feedback amplifiers in WW somewhere ,an article  from Mayo and the BBC , well worth a look if it can be found ,the handy thing is each writer is meticulas in providing references ,so each article provides new leads on old gems .