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Re: Relay I/O Current
Quote:
Originally Posted by Al Skierkiewicz
Mike,
R39 F relates to powered devices, which in the case of the DSC is the servo outputs with the jumper in place to feed 6 volts to those outputs. The digital I/O and relay outputs cannot sink or source enough current to feed LEDs without a driver of some sort. If you look at the schematic for the DSC, you will see that the relay outputs feed a small LED in parallel with the relay output. The output current on that LED and the relay drive about max out the chip capability of 16 ma per output. The LEDs on the board are low current devices speced at 5 ma each.
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I was under the impression that the general purpose digital outputs on the DSC could source much more current than that, in fact, we've used it to successfully drive a 65mA blue LED with no observed side effects.
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Matt Krass
If I suggest something to try and fix a problem, and you don't understand what I mean, please PM me!
I'm a FIRST relic of sorts, I remember when we used PBASIC and we got CH Flightsticks in the KoP. In my day we didn't have motorized carts, we pushed our robots uphill, both ways! (Houston 2003!)
Last edited by Matt Krass : 08-02-2011 at 12:27.
Reason: Clarified.
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