distortion in transformer cores, N. Partridge, 1939

This is the first of a series of articles in which the question of amplitude distortion arising in the iron core of a transformer will be dealt with on a quantitative basis. Information on this subject is scarce and the design data given is the outcome of original research by the author.

Be aware that tis articles appeared in the The Wireless World magazine from around 1939 (!). I’ve found some decent scans here: 1, 2, 3, 4.


transformer signal path distortions – part 1

transformer circuit symbol


“Audio-frequency transformers are used mainly for matching impedances and transmitting audio frequencies. They also provide isolation from direct currents and present balanced impedances to lines or circuits.” (cited from Reference Data for Engineers: Radio, Electronics, Computers and Communications from Wendy Middleton, Mac E. Van Valkenburg)

In other words, they are most commonly used for two purposes: One is the isolation between two sections of an electric system which have different ground levels and another one is to change voltage levels (as is typical for tube circuits for example). [Read more…]