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Transformer Windings (not Wingdings)
Name: Peter
Status: Student
Grade: 9-12
Location: NY
Country: United States
Date: August 2006
Question:
What are 'wingdings' in an electrical transformer?
Replies:
There are no "wingdings" in an electrical transformer.
At least in my opinion, someone else may have a different feeling about it.
There are "windings", which of coarse are the conductive copper
coils around the magnetic iron core.
So I bet you saw a miss-spelling.
On rare occasions an electrical schematic might contain a symbol for
a "saturable reactor" type of transformer.
It's not used as a transformer (AC in, AC out),
but rather as a DC-adjustable inductor (DC current through control
winding, AC voltage trying to get through the power winding).
Physically it is different from a regular transformer only in small
details of the magnetic material used, the shape of the core, and
the turns ratio.
All inductors with magnetic cores saturate.
At a certain [current x turns] product the material in the core
cannot be magnetized any more strongly,
so the magnetic field in the core stops growing,
so no back-emf is created to oppose current flow from the voltage
being applied,
so current starts getting much larger. That is why AC power
transformers have an input-voltage limit.
But in saturable reactors, all the little design aspects are optimized
to make it a fairly sharp change instead of a muddy, gradual change,
and the control winding is given a DC current to use up a
controllable amount of the core's maximum flux.
In the schematic, to distinguish this type from a regular transformer,
little right-angle offshoot lines are added to the end of the
double-lines which denote the iron core.
It is quite reminiscent of the tabs added to the symbol for a diode,
to make it a "zener diode".
After all, the core "saturates" abruptly at a given magnetic flux,
much like a zener diode starts conducting abruptly at a given voltage..
If somebody called those little offshoot lines "wingdings" I would
not be too surprised.
But those are merely part of the symbol;
there is no corresponding part in the actual device.
Jim Swenson
Hi Peter,
Actually, there are no "Wingdings" in a transformer! I think you may
have been
referring to "Windings". Please note that the word "Wingdings" does
in fact appear
in several web sites in relationship to transformers, but every
instance I have seen
is clearly a misspelling of the word "Windings". Perhaps you had
seen this rather
amusing error and were wondering about it?.
By further explanation, a transformer consists of a magnetic "core" commonly
made of a special type of steel or a magnetic material called
"ferrite", a "primary
winding", and one or more "secondary winding(s)".
These "windings" are many turns of copper wire that are wound around
a place in
the core. If there are fewer turns of wire that are wound in the
secondary section as
compared to the number of turns in the primary, the voltage that the
secondary
winding delivers will be lower than that which is the fed to the
primary. If there are
more turns of wire in the secondary section than the primary, then
the secondary
will deliver a higher voltage than that which is fed to the
primary.
Regards,
Bob Wilson
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