[dorkbotpdx-blabber] ARRGGHH - Please check this circuit

[Mykle Hansen]

On Jan 12, 2009, at 5:53 PMMonday, Hans Lindauer wrote:

> I had hoped that putting a capacitor on the microcontroller's power  
> rail would help (I even figured out to put a diode going into the  
> cap), but it still isn't working.  I think the problem is that 5V  
> doesn't provide enough overhead, and trying to use caps to take up  
> the slack is only going to be marginal at best if I want to be able  
> to run the LEDs at full brightness (which I do).
>
> So my next step is to try powering it off of 12V instead of 5V.   
> BUT... when I tried that before, it burned out my LED after a few  
> minutes (and I can't afford to burn out too many of those, they're  
> expensive).  The guy who posted the driver circuit I'm using claims  
> that it works for 3V-60V, but obviously I've found an exception to  
> that.

as i understand this, voltage is only one parameter
of a power supply.  the other is amperage -- i.e.
how many electrons can the supply deliver at
a given voltage.  if you draw more amps at 5v
than the supply can provide, the voltage will drop,
leading to problems like you describe.

so rather than going to a higher voltage supply,
you maybe want to go to a higher amperage one.

-m-
---
HELP!  A Bear is Eating Me!
http://helpabeariseatingme.com

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