RE: Saturable Reactors (yes, again :)) (fwd)

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Original poster: Steven Roys <sroys@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Sat, 18 Feb 2006 08:49:37 +1300
From: G. Tyler <gtyler@xxxxxxxxxxxxxxx>
To: 'High Voltage list' <hvlist@xxxxxxxxxx>
Subject: RE: Saturable Reactors (yes, again :)) (fwd)

You need a certain amount of amp turn to saturate, as you say, but that
current is a very small part of what you actually need when it is driving a
load. The current in the ac, controlled winding "fights off" the control
current. The amp-turns on the control side will equal the amp-turns on the
controlled side, and this is many times what you need to saturate the same
mag amp with no current in the controlled windings. A mad amp will normally
have much more turns of thinner wire on the control winding than the
controlled, otherwise the control current gets very high.
	Also remember that the DC resistance of the control winding sets the
DC voltage across it, so if you don't have many turns of thin wire you will
control with a very low voltage, which can be inconvenient. Imagine your
control needing 100Amps at 1Volt rather than 1Amp at 100 Volts, as well as
your control circuitry working with this. 

-----Original Message-----
From: High Voltage list [mailto:hvlist@xxxxxxxxxx] 
Sent: Saturday, 18 February 2006 4:00 a.m.
To: hvlist
Subject: RE: Saturable Reactors (yes, again :)) (fwd)

Original poster: Steven Roys <sroys@xxxxxxxxxx>



---------- Forwarded message ----------
Date: Wed, 15 Feb 2006 10:22:39
From: David Dameron <ddameron@xxxxxxxxxxxxx>
To: High Voltage list <hvlist@xxxxxxxxxx>
Subject: RE: Saturable Reactors (yes, again :)) (fwd)

Hi Carl and all,
Modifying a center tap transformer as you suggest won't work. The 2 fluxes
would just cancel and you would have nothing except something like a
non-inductive winding. You need 2 or more magnetic paths. 2 separate single
phase transformers would work with the outputs bucking, they can be
toroids, EI construction, etc. I used to have a sheet with several unusual
configuration drawings, am looking for it. I have tried the 2 transformer
approach with small transformers.
The number of turns on the control windings doesn't need to be larger than
the AC series (power) one, a certain amp-turns is required to saturate, and
the number of turns gives what control amperage is required.
-Dave D.

At 08:23 AM 2/14/06 -0700, you wrote:
 
>
>Since either the control or the power may apparently consist of 2
>windings as long a there is no net voltage induced into the control, I
>wondered if the transformer removed from a small pole pig might also
>work well.  Isn't the low voltage side provided with a center tap?  If
>so, it would seem that this might be split into 2 at that point and the
>same wired in series opposing so that the net fluxes cancel and the HV
>side used as the control.
>
>Any thoughts on this?
>
>Carl Litton