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Re: DC power supply

> Well, I really didn't think he wanted to fly the hood.  What you do not
> understand is that once you start to build a power supply, there is no
> particular savings to build one rated at less than 3 or 4 amps.  If the fan

If you look at the small 12v or 5v fans, they use far less than even 1 amp.
The largest current draw I saw was a 12v fan that draw 350ma, and moved 85cfm. 

And at those low currents, simple wall-wart transformers work perfectly.  They
don't need good regulation.  They are just spinning a fan.   I've already 
priced two or three different suitable 12v or 5v power supplies for under
$5.00 each.      There are several cheap 12v power supplies that will provide

> store.  Incidentally, why not just buy a 115 VAC muffin fan?  That doesn't
> require any power supply at all, and moves more air to boot.

I like the dc ones.  Typically less noise, and a cheap $3.00
wire-wound pot can be used to control the speed.    Also, because the
low voltage and low current, I have no fear suggesting to beginners that
they wire this up themselves.   I've dropped my low-voltage LED lights 
into the tank before while they were on, no problems.     

Only downside to the DC wall-warts is that they take up too much
space on the powerstrips.  

Chuck Gadd