1...Removing Magnetic Shunts??

[Randy Gross]

I read a very good analogy of Magnetic Shunts at the Pupman site where it
was discussed that the shunts were like putting a large inductor in series
with an Ideal transformer, diverting a portion of the flux back to its
source.

By removing the shunts, I assume the full rated KVA of the transformer is
available? My question is: What are the negative effects (if any) of this
action?

 

[Don Kelly]

I read a very good analogy of Magnetic Shunts at the Pupman site where it
was discussed that the shunts were like putting a large inductor in series
with an Ideal transformer, diverting a portion of the flux back to its
source.

By removing the shunts, I assume the full rated KVA of the transformer is
available? My question is: What are the negative effects (if any) of this
action?

----------
I would be interested in this article -where is it on the site? If my
understanding of magnetic shunts is correct, the analogy you mention is not
a good one. I see these as simply a way to divert some of the primary flux
so that it doesn't couple the secondary winding (i.e. making the
transformer poorer). This would decrease the output voltage at all
loads -somewhat different than the effect of a series inductor.
Without more information I cannot analyse the device and my comments above
may be dealing with a different concept in a different application.

 

[Stepan Novotill]

----------

Now I thought that magnetic shunts were used mostly in ferro-resonant
transformers such as in microwave ovens and street lights for
secondary voltage regulation. The shunts cause the coupling into the
secondary to saturate at a certain primary resonant current, to limit
output voltage in the secondary. This resonant current is also high
enough to store significant energy so you can get through a missing
cycle. If you remove energy from the secondary, the shunt unsaturates
and more energy is coupled into the secondary. Removing the shunt will
cause the secondary voltage to rise and will destroy the resonance
with the capacitor on the primary.
Please correct me if I'm wrong.

....Stepan

 

[cornytheclown]

I read a very good analogy of Magnetic Shunts at the Pupman site where it
was discussed that the shunts were like putting a large inductor in series
with an Ideal transformer, diverting a portion of the flux back to its
source.

By removing the shunts, I assume the full rated KVA of the transformer is
available? My question is: What are the negative effects (if any) of this
action?

Not being a professional ee or designer like some of the others claim
to be... I think the rated kva of a transformer with current limiting
shunts is with the shunts installed....in other words the core is
designed to include the shunts

If the transformer is designed to be operated with the shunts
installed then removing too many or all of them would cause the core
to saturate...the primary will draw more current and the secondary
output will not see any increase........you could burn up the primary
windings

When you remove a few shunt plates you will increase the current
output on the secondary but will generate more heat in the transformer
and if you remove too many shunts you may risk burning up the
secondary winding or windings.

I would remove a few shunts at a time and would then test the
transformer monitoring input current and output current.....you will a
reach a point where the input current and heat keeps rising with no
significant increase in output.
Doing any more will only saturate the core.

Ive done quite a few neons and oil burner igniton transformers.....did
a couple of oddball transformers. Never left more than 50 percent of
the plate out though......

Now then........lets see........I bottom posted so that will keep the
really anal off my back here .....oh.... I must warn you that I am a
hobbyist and not an engineer with a design business in my basement or
spare bedroom like some of the more educated guys on here.......but I
have offered this post from my personal experiences.......

be carefull......experimenting with electricty can kill you or at
least turn you into a complete asshole like it has done to a few of
the posters in here...

 

[John Fields]

be carefull......experimenting with electricty can kill you or at
least turn you into a complete asshole like it has done to a few of
the posters in here...

One for sure... Keeping one hand in your pocket doesn't mean you can
use the other one to adjust the spacing of a Jacob's ladder when it's
running.

 

[Stepan Novotill]

On Sat, 27 Sep 2003 13:46:23 -0500, John Fields

Could someone please post a picture of the core and shunt plates?
Or a link to a picture? Thanks