wrote:

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


-- snip --

Right. Aluminum has better conductivity per gram than copper. I
understood that even before you original post.

I also know that aluminum also has much _worse_ conductivity per unit
_volume_. And that the core that you're going to put it on can probably
accept a finite volume of wire. Since 12 gauge wire has about 50% more
area that means that you're only going to be able to put on 2/3 as many
turns, meaning your inductance is going to be about half of what you'd
get with copper wire. Even with a toroidal core you're still left with
about 2/3 your inductance.

That means that you need to go to a bigger core to get your inductance
up. Not only does this mean that you'll be adding a lot of mass, but a
bigger core will require more wire, so when you're done you won't be
getting a 2x savings in wire mass, and you'll more than likely have an
inductor that is actually heavier than the copper alternative.

So, to repeat, have you run _all_ the numbers and verified that you'll
achieve a savings?

--

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com