Re: Potato Chips (fwd)

---------- Forwarded message ----------
Date: Tue, 28 Apr 1998 05:04:55 GMT
From: Jim Fosse <jim.fosse-at-bjt-dot-net>
To: Tesla List <tesla-at-pupman-dot-com>
Subject: Re: Potato Chips (fwd)

>Date: Mon, 27 Apr 1998 21:14:03 -0500
>From: teslaman-at-juno-dot-com
>To: tesla-at-pupman-dot-com
>Subject: Re: Potato Chips (fwd)

>>	I used to think that also but, I've 2 1kW arc lamp ballasts
>>that are shunt regulated auto transformers that have the laminations
>>arc welded together. Several of my microwave transformers are also arc
>>welded together. I now think that the varnish, besides insulating the
>>windings and holding them together, keeps the laminations from
>>vibrating and generating acoustic noise.
>>	jim
Well, I just checked and find I have to retract my statement. The
ballasts do not look varnished, but are insulated never the less. The
MOTs are both varnished and welded.

	so much for memories of a thread from last year;(


p.s. this one's been bugging me. I just went out to the garage and
double checked ALL my xfmrs. It's my depoted 15kV 60mA neon (no
sandblasting here;) that shows bare cores to my ohmmeter.


>Jim, Bert..
>  More light to shed on this discussion, your both right.   Transformers
>which are designed for high efficiency and long periods of continuous
>operation do take precautions to lower eddy current and hysteresis
>losses.    Many transformers are rated intermittent duty such as
>microwave ovens, electric welders, battery chargers etc...and are
>sometimes welded instead of using clamps to hold the core together.  To
>reduce eddy current loss, the cores are made from thin silicone steel
>laminations which in themselves offer some electrical resistance.  
>Additionally each strip of lamination has a layer of insulating film on
>their surface, and yes, it does help to eliminate core noise from
>electrical vibrations.>
and neons are just made cheeply!