Re: [CAD_CAM_EDM_DRO] Transformer 101? was Re: New Pix UP!

I guess the phrase "virtually all" does need some qualifying. A good E-I
design can "approaches" a toriod in efficiency (that needs qualifying
too!).

"built right":
keep your core losses less than copper losses, "drive" the core to not more
than 13 Kgauss with 26 ga laminations, and less than 14.5 Kg when using 29
ga,, balance primary copper losses with the secondary losses, employ a
static shield, and above all, cram just as much copper wire in there as
possible. Design for maximum efficiency, & lowest regulation. I've worked
with a program that can do that. Takes about 20 seconds to yield a nominal
design from which one can do some "fudging" with parameters. (Turns, wire
sizes, core stack, interleave, lamination size & gage, add cooling ducts,
etc). Contact me off-line, & I'll design a sample, if you're interested
(not all 2118 of you!).

used transformers: look for low regulation, low temp rise, very little
empty space in the windows, varnish or epoxy impregnation, less than 3 x 3
interleave, good workmanship (most people won't put much craftsmanship in a
product that they know is just, junk)

RayHex

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> From: ballendo <ballendo@...>
> I've understood this to be true of toroid construction. Is it also
> true for I-E types?
>
> Could you elaborate on what means "built right" with respect to the
> types of power transformers this list would typically use?
>
> What should we look for when deciding between two or more (surplus)
> power transformers, assuming volts and amps meet our needs...?
>
> Thank you in advance.
>
> Ballendo