Failed Mail...

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: "Bert Hickman by way of \"Terrell W. Fritz\" <terrellf-at-qwest-dot-net> by way of Terry Fritz <twftesla-at-qwest-dot-net>" <bert.hickman-at-aquila-dot-net>

Hi Terry!

I just tried to forward a response to the list (twice), and got the
following Failed Mail message (relaying denied??). Could you add the
following message to the list messages once the problem is corrected?
Aren't virii and worms wonderful! :^)

Thanks!

-- Bert --
-- 
Bert Hickman
Stoneridge Engineering
Email:    bert.hickman-at-aquila-dot-net
Web Site: http://www.teslamania-dot-com

 ===== transcript follows =====

TO: tesla-at-pupman-dot-com [550 5.7.1 <tesla-at-pupman-dot-com>... Relaying denied]

  ===== Unsent message follows ====
>From bert.hickman-at-aquila-dot-net Sat Aug 18 10:20:35 2001
Received: from il0015dacsopc3.elmhst1.il.home-dot-com ([24.253.81.52]) by
ns2.aquila-dot-net
        with SMTP (IOA-IPAD 2.70a/96) id 2715500; Sat, 18 Aug 2001 10:20:35
-0500 
X-Mozilla-Status2: 00000000
Message-ID: <3B7E7AFD.53E57435-at-aquila-dot-net>
Date: Sat, 18 Aug 2001 09:26:05 -0500
From: Bert Hickman <bert.hickman-at-aquila-dot-net>
Organization: Stoneridge Engineering
X-Mozilla-Draft-Info: internal/draft; vcard=0; receipt=0; uuencode=0;
html=0; linewidth=0
X-Mailer: Mozilla 4.75 [en] (Win95; U)
X-Accept-Language: en
MIME-Version: 1.0
To: Tesla list <tesla-at-pupman-dot-com>
Subject: Re: Xfmr Core Area
References: <4.1.20010817204433.00a2ab50-at-pop.dnvr.qwest-dot-net>
Content-Type: text/plain; charset=us-ascii
Content-Transfer-Encoding: 7bit

Greg and all,

The power handling capability for an "unknown" silicon steel core of cross
sectional area "A" operating from a sinusoidal 60 Hz source can be roughly
estimated by the following formulas. Note that the core area is the area
directly beneath the windings (usually the center "leg" in an E-I core).

  P (at 60 Hz) = (A/0.16)^2  where P is in VA and A is in square inches.

Solving for 7 and 12 square inches respectively (60 Hz):

  P(A=7)  ~ 1900 VA
  P(A=12) ~ 5600 VA

The above equation can be modified for operation at 50 Hz:

  P (at 50 Hz) = (A/0.192)^2

Solving for 7 and 12 square inches respectively (50 Hz):
  P(A=7)  ~ 1300 VA
  P(A=12) = 3900 VA

It will take significantly more "iron" in the core to handle the same
amount of power at 50 Hz compared to 60 Hz. More exact estimates require
using core and winding window areas, manufacturers core tables, or a
magnetics program.

Best regards,

-- Bert -- 
-- 
Bert Hickman
Stoneridge Engineering
Email:    bert.hickman-at-aquila-dot-net
Web Site: http://www.teslamania-dot-com

Tesla list wrote:
> 
> Original poster: "Gregory Hunter by way of Terry Fritz
<twftesla-at-qwest-dot-net>" <ghunter31014-at-yahoo-dot-com>
> 
> Dear List,
> 
> I've read conflicting information about the
> relationship between the cross-sectional area of an
> iron core xfmr and power handling capability. Lemme
> get specific. If I wind a homebrew HV xfmr on an iron
> core with a cross section of 7 sq inches, how many VA
> can I reasonably expect to draw from it? What about 12
> sq inches?
> 
> Many Thanks,
> 
> Greg
> http://hot-streamer-dot-com/greg
> 
> __________________________________________________
> Do You Yahoo!?
> Make international calls for as low as $.04/minute with Yahoo! Messenger
> http://phonecard.yahoo-dot-com/