Can't you just up the frequency of the converter a bit? That would reduce
the flux density in the transformer, or the filter choke inductance,
depending on the type of converter you use. A reduced flux density would
allow the use of smaller cross section magnetics and less turns of wire. The
net result is a saving in weight and cost. Then you may consider the use of
copper wire. The wire losses only go up as the square root of the frequency
for solid wire, and the wire resistance is primarily determined by skin
effect once you get up past a few KHz in frequency. In fact you will have
less total losses using copper Litz wire of a size smaller than using solid
aluminum wire.

If your current requirements are low you can "manufacture" your own small
gage Litz wire of sorts by twisting together a number of strands of fine
solid round magnet wire. The size of the wire strands depends on the
frequency of the current the wire must carry. If your requirements are real
small some of the Litz wire manufactures may have some left over scrap of a
type you can use they would sell you.

http://www.mwswire.com/litzmain.htm
http://www.litz-wire.com/
http://www.dartmouth.edu/~sullivan/litzwire/litz.html (Litz wire theory,
solor powered car app.)

--
Leland C. Scott
KC8LDO

Wireless Network
Mobile computing
on the go brought
to you by Micro$oft

wrote in message
...
Aluminum is the lowest weight conductor.
Copper, Silver and Gold have lower drop per unit area, but

Al is the lightest.


12Ga suqare Al has 2.260 ohms per K ft.
Weighs 7.28 lbs per K ft.

14 Ga Cu has 2.239 ohms per Kft
1Kft weighs 14.99lbs


6% more resistance at half the weight.

From the same chart
11 Ga Al has 1,755 ohms and a wt of 9.237

See:

http://www.mwswire.com/square.htm

I can buy wire from these guys' but they have a $100.00 minimum per line
item.

Paul




On Wed, 05 May 2004 13:05:05 -0700, Tim Wescott
wrote:

wrote:

I'ts a power converter for my Solar RC plane.
The inductors and the wires carying the current to the motor are a
significant part of the power system weight.

Paul



On Wed, 05 May 2004 10:21:14 -0700, Tim Wescott
wrote:


wrote:

Anyone know where I can find/ purchase a small qualtity
(Or any quantity) of Aluminum Magnet Wire?

Looking for 12 or 14 Ga AL magnet wire, square would be better, round
is acceptable.

Paul (Kl7JG)

Why? It's way less conductive than copper, so unless you're making an
air-wound coil that needs to save a few ounces I can't see how you'd
save anything using Al over Copper.

But I'm willing to be educated.



I suspect that you have a choice between (a) losing more power to
resistive losses because of the lower conductivity of aluminum or (b)
_increasing_ the weight of your power converter because you've increased
the core size to save on resistive losses. You may be able to do better
with _silver_ wire and a smaller core, for all I know.

This doesn't mean that you shouldn't make the attempt, I'm just
wondering if you've taken all the variables into account.

Have you already pushed the switcher frequency up to insane levels?
Looked into resonant topologies, all that stuff?