View Single Post
  #20   Report Post  
Posted to rec.audio.pro
Ralph Barone[_3_] Ralph Barone[_3_] is offline
external usenet poster
 
Posts: 60
Default I Built and Used My First Incandescent Bulb Current-Limiter

wrote:
Paul wrote:
============

** The largest part of the " inrush surge " is down to the iron transformer
core *magnetising* and losing nearly all of its inductance at switch own.


Can take 20 cycles of AC power for the core to unmagnetise too.

SMPSs usually surge hard at a switch on too, yours must be an exception.


The iron transformer is magnetizing every cycle, which
would be 60 times a second, for 60Hz AC.


** But not at *switch on * !!!!!!!!!

The phenomenon is called " inrush surge" and is a *whole subject* on its own.

This article from my colleague Rod Elliott may give you a hint.

https://sound-au.com/articles/inrush.htm


.... Phil




Section 4 of your linked article talks about transformer inrush, which is a
definite concern for equipment with large power transformers. We had an
event a couple years ago when energizing some 500 MVA, 500 kV transformers
at the wrong point on wave resulted in a large outage and actual
destruction of some other equipment in the vicinity.