Re: [CAD_CAM_EDM_DRO] Power Supply

Fernando, assuming you're across the big pond, and have 200volts AC for
input, and want 200 Volts AC output, at 50 Hz, and are only looking for a
1.5 KVA isolation transformer, with about 4% regulation:

If you want to really 'do it yourself', get a square cardboard tube about 2
53" x 2.53", about 3 .66" long, mounted on a suitable mandrel, so it won't
collapse while winding (make sure you can get it off the mandrel, after
winding). Now, using # 12 ga copper magnet wire, and allowing yourself
about 6" to 8" of wire stick-out, anchor the first winding turn with
fiberglass tape to the tube, so the first turn (total primary will have 166
turns) will wind about 1/4" from the edge of the tube, wind 34 turnsof
wire, finishing about 1/4" from the opposite edge of the tube. (While
holding tension on the wire), wrap a 10 mil kraft-paper wrapper over the
first layer, overlapping about 1" on the leadwire side of the coil. Wind
another 34 turns (this time, back towards the stick-out lead end of the
coil, 1/4" from the edge, again. Apply another wrapper, and another 34
turns, another wrapper, another 34 turns, another wrapper. Now you've got
136 turns, so you need another 30 turns on the 5th layer, anchor the last
turn, and lay it across the outer layer, with a 40-mil strip of paper
UNDERNEATH it, so it sticks out the same end as the 'start' lead, and call
this the finish lead. Place a 40 mil wrapper over that last layer, to
insulate it from the secondary winding. The secondary consists of 172 turns
of #12 ga copper, wound over the primary, 5 layers of 35 turns per layer,
in the same way as the primary, including 10-mil layer insulation. Start
the secondary lead on the 'other' side of the coil as the primary. While
winding, using a rubber hammer, flatten the two sides of the coil that will
be inside the 'windows' of the lamination. (A rubber hammer works well for
this) The winding project will work pretty good, if you can wind it on a
lathe that's turning 'backwards' (i.e. top going away from you). NOTE:
Unless you planned ahead, sliding the coil off the mandrel will be a real
bastard... You'll need about 8.5 lbs of wire, if you do a neat job. Also,
you'll need about 25 lbs of 2.5" EI laminations, 24 (24 guage is cheaper),
26, or 29 (29 guage runs cooler) guage. Laminate, alternating 2 x 2 or 3 x
3 the E's through the coil center, minding the flattened sides go in the
window openings of the E's. When the stack is completely filled, insert the
I's in the openings left on either end of the stack, where the E's ended.
Mind that the (reference) bolt-holes in the E-I pairs of laminations line
up. Bolt the stack together with 3" bolts, and appropriate brackets. Dip
the unit in a varnish vat that's been heated to about 150° F, and let sit
for a few hours to let air bubbles out (if you don't have access to a
vacuum chamber). Drip-dry, then bake at about 250° F. for a few hours, and
sleeve the primary and secondary leads. Lotsa work, huh? Now you know why
an equivalent X-former will cost you about $180.00 to $300. This unit is
predicted to have about an 80° C. temperature rise at 100% power, 100%
duty-cycle. DISCLAIMER: The above is a typical transformer design that
may, or may not suit your needs. If you choose to make one to the above
spec's, you must hold me harmless in event of your (or anybody else's)
injury, or other mishap. Contact me off-list, if your requirements are
different from what I assumed.

RayHex


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> From: Fernando <fer_mayrl@...>
>
> Hello,
> Im going to start building my first router, it will be fitted with 4
> Reliance 690 DC brushed servos rated at 4 Lb-In, which will be
> driven with 4 rutex drivers, R90H (200V/40A) or R990H2 (200V/10A),
> (Sugestions Welcomed). I think I will be using mach 2 for software.
> The only thing missing is the power supply, I was looking at a 1.5KW
> power supply by cnckits.com, but I think its a little bit pricey,
> Does anyone know where I can get a good, reliable power supply for
> this setup? Theres no problem with building one myself, so any info
> regarding a good dealer, or plans would be very welcome, Along with
> the recomendation of which driver should I go with.
> Regards
> Fernando Mayrl