Subject:
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Re: Homemade LED Bricks
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Newsgroups:
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lugnet.robotics
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Date:
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Fri, 12 Nov 1999 03:04:44 GMT
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Viewed:
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871 times
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Michael Gasperi wrote:
> David Johnston <lego-robotics@crynwr.com> wrote in message
> news:LOBBJCENKNHFLCKICLNNIEODCAAA.djohnston@tinet.ie...
> > not being an electronic engineer, what is "appropriate"?
>
> I'd say 330 Ohm 1/4 Watt.
Er, 330 ohm may be ok for the usual transistor type circuit where the
nominal supply voltage is 5 volt, if my memory has not failed me.
It may be a bit low, I think, for the RCX where the nominal voltage is 9
volts which is almost double of 5 volt. So maybe a resistance of 680
ohm would be more "appropriate"?
But then I'm not an electronic engineer either. Just wanted to be sure.
--
C S Soh
http://web.singnet.com.sg/~cssoh
... where air is power
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Message has 1 Reply:
 | | Re: Homemade LED Bricks
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| basicly.. it's i*r=v where i = current in amps and r = resistance in ohms and v = voltage in volts.. so.. If we want to find out the resistor's value.. we re arrange it like so.. r = v/i so 10 millamps (typical led current) = .01 Amps.. And at 9 (...) (25 years ago, 12-Nov-99, to lugnet.robotics)
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Message is in Reply To:
| | Re: Homemade LED Bricks
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| David Johnston <lego-robotics@crynwr.com> wrote in message news:LOBBJCENKNHFLCK...inet.ie... (...) I'd say 330 Ohm 1/4 Watt. (25 years ago, 12-Nov-99, to lugnet.robotics)
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