[dorkbotpdx-blabber] 12 volt 20 amp power supply to drive a couple of pumps

[Dem Chi]

Yes, the input source is the AC line. I'm trying to keep the component count
low. I need a 24Volt line at 0.4A. A 12V line at 20A and a 10V line for the
arduino. I really didn't want to have a bunch of transformers sitting around
in there if I could help it. The PC power supply idea is a good one. I guess
I could use a step-up transformer to get my 24Volt line off of that...hmm.
Besides, the transformers aren't all that cheap by themselves.

I suppose it is a bit of power I'm trying to dissipate...bleh.

Thanks for your response.

On Sun, Mar 15, 2009 at 7:42 PM, John Luciani <jluciani at gmail.com> wrote:

> The problem is you need to drop too much voltage across your regulator. You
> will need to dissipate 240W (12V * 20A). You could parallel devices with
> diodes but it is still a lot of heat (just spread out a little more).
>
> You either need to get a transformer with a lower voltage output or use
> a DC-DC converter.
>
> Is the input power source the AC line (120VAC)? If it is the cheapest way
> to get
> 12V @ 20A would be a PC power supply.
>
> (* jcl *)
>
> On Sun, Mar 15, 2009 at 10:23 PM, Dem Chi <dementedchihuahua at gmail.com>
> wrote:
> >
> > Hi all,
> >
> > I'm making a power supply to drive two 12V 8amp DC motors. They are for a
> > filtration box. They will be used both intermittently and sometimes for
> long
> > durations. I've got a bridge rectifier from mouser rated for what the
> > transformer that I have outputs (621-GBJ20005-F). I'm getting a 24V line
> at
> > ~20 amps. I need to take this down to a 12 volt line and current limit it
> so
> > that I don't burn up my pumps. I am also taking off a 10 volt line for an
> > Arduino but this is less important at this point.
> >
> > My problem is that voltage regulators that I've found--not many--that can
> > take 24 volts and output 12 volts with 20 amps are expensive. Can anyone
> > suggest a circuit or IC or anything that will take the 24 volts I'm
> giving
> > it and output a 12 volt 20 amp line?
> >
> > Priorities are cost and ease of construction. No surface mount parts or
> > anything like that.
> >
> > Any help is good help! Thanks
> > Stan
> > --
> > http://www.urbansurvivalists.com/
> >
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> >
>
>
>
> --
>
> You can't create open hardware with closed EDA tools.
>
> http://www.luciani.org
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