[sdiy] inductor based distortion

[René Schmitz]

Hi List,

Glen wrote:
> At 05:48 AM 6/3/03 , Michael Zacherl wrote:
> 
>>Hi,
>>wouldn't that kill (i.e. the core becomes a 
>>magnet) the transformer after some time?
> 
> 
> Power amps made with tubes, commonly have several hundred volts DC applied
> to the output transformer's primary winding. It doesn't seem to "kill"
> those transformers. 

Right, the iron used for those cores is magenetically soft. Very small 
remanence. As soon as an external field is applied the remanent field 
vanishes, and the material magnetizes in the direction of the external 
field.

However the actual DC drop over the primary might be only some 20V or so 
for a typical tube amp. If the core has a bias current/magnetisation 
(single ended) then there is an air gap incorporated into the core to 
keep the core from saturating.

Cheers,
  René

-- 
uzs159 at uni-bonn.de
http://www.uni-bonn.de/~uzs159