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Re: Wire gauge
Tesla List wrote:
>
> Original Poster: "Samuel Rosset" <samr-at-chez-dot-com>
>
> I have a problem with converting the gauge in inches, for I have several
> sources and they are different. For example, with one source, a #26 AWG
> would have 58 turns per '' and another one says there are 63 turn per ''
> Does anyone know the diameter for the wires AWG #26, #24 and #22
>
> Thank you
>
> Sam
Sam,
The difference is due to insulation thickness. If you used bare #26 AWG,
you could approach about 63 turns/inch. However, in a working coil
you'll be using insulated wire, and about the best you'll see is 59
turns/inch if you use a single layer of conformal insulation. The
nominal diameter of magnet wire increases as you add successive layers
of insulation (called "builds"). The more build layers, the fewer the
number of turns/inch you'll get (i.e., lower inductance), but the
greater the turn-to-turn insulating capability (better high voltage
stress handling).
The ACTUAL number of turns/inch that you'll see will usually be a bit
lower, since its quite difficult (on a hand-wound coil, at least) to
consistently get the adjacent turns to butt together together. You can
usually see see some of the coilform peeking between the turns if you
look closely. To take this into account, I usually derate the number of
turns by multiplying the theoretical turns/inch by an adjustment factor
- typically 94% to 97%.
Magnet wire can go from single build to quadruple build. A good
compromise is to go with "double build", or "heavy build" wire. The
table below is taken from Essex Wire:
(Inches)
Nominal Turns/
AWG: Build: Diameter: Inch:
=== ===== ======== ====
#22 Bare 0.0253 39.5
#22 1 0.0266 37.6
#22 2 0.0276 36.2
#22 3 0.0286 35.0
#22 4 0.0298 33.6
#24 Bare 0.0201 49.8
#24 1 0.0213 46.9
#24 2 0.0223 44.8
#24 3 0.0232 43.1
#24 4 0.0243 41.2
#26 Bare 0.0159 62.9
#26 1 0.0170 58.8
#26 2 0.0179 55.9
#26 3 0.0187 53.5
#26 4 0.0198 50.5
Hope this helps, and good luck on your coil!
-- Bert --