On Thu, Feb 23, 2006 at 12:29:30AM -0800, Jose Da Silva wrote:
> On February 22, 2006 11:45 pm, Peter Todd wrote:
> > Anyone have any experience with this? I just started a project that
> > will be a cube with 6 led matrix displays, one on each side, using
> > 5x7 led modules. Each side will end up as a 35x35 matrix that will
> > then display a 3d rendered wireframe image of a cube.
> 
> That's only 7350 LEDs.
> Maybe you should add another LED to indicate you have power to your 
> circuit in case someone needs reassurance the circuit is turned on ;-)

That's a good idea, but you know, sometimes LED's fail, maybe I should
bolt a neon tube to it, for redundency?

> > One challenge I see is power. Peak power, for all leds on, is about
> > 16 amps per side! Or about 100amps for the whole board! That's just
> > nuts... Is there such a thing as a simple, self-contained switching
> > regulator that can handle a decent amount of current? I'd like
> > something as simple as a 3-pin regulator, no external components or
> > anything. I'm trying to have this thing completely built by March
> > 11th, which I know is utterly insane, but trying is fun!
> 
> You can try reducing current by stacking the voltage planes. 6 boards... 
> that would be 100amps/6 = 17amps.
> Divide by 4 and you are needing 4amps x 24 layers, or 120vdc to power 
> your tower of 5v x 24layers.
> 
> One set of boards driving your LEDs etc runs at 0-5v,
> Another set runs on the 5-10v layer,
> Another set runs on the 10-15v layer,
> Another set runs on the 15-20v layer.....

Hmm... Sounds like a bit of a routing nightmare to me. I'd be running
things in series, so I'd have to "route" the voltage from one board to
another. If it's just running the boards in series, they'll use vastly
different amounts of current as the pictures change, probably not going
to work.

Thinking outside of the box is good though. For that matter, why must it
be a box? :)

> Another thing is, if you are running identical pictures on each side, 
> then you can also reduce the circuitry by 6 by putting 6 LEDs in series 
> controlled per driver. You'll need a different driver most likely since 
> you'll be needing a higher voltage.

Ahh, see, they aren't identical pictures, they are 3d-renderings of an
identical object, but from different angles.

Nice idea though, very sneaky for the right application...

-- 
pete@petertodd.ca http://www.petertodd.ca
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