Re: Best way to power array of LEDs?

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#293

From: Roger Dewhurst
Date: Fri, 04 Oct 2002 20:26

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"Lizard Blizzard" <NOSPAM@rsccd.org> wrote in message
news:ank9ep$lumv$1@hades.csu.net...
> Jerry G. wrote:
> > Each LED must have its own series resistor.
>
> NO, the rule is that is very unwise to connect LEDs in
parallel.  There
> is no problem connecting multiple LEDs in series, contrary to
your claim
> above.  LEDs connected in parallel must be very closely matched
for
> forward voltage drop so that one LED will not hog the current
and
> self-destruct.
>
> >  Most of these LED's work
> > at about 30 to 40 ma with about 1.6 VDC across them.  You
should be able
> [...]
>
> Most IR LEDs have 1.6V drop.  Most modern red LEDs have 1.9 to
2.1V
> across  them.  Yellow and green LEDs have a higher voltage, up
to 2.4V.
>   Blue and white are 3.4 to 3.6V.
>
>
> > LED's cannot be wired in parallel to each other being fed
from one
> > resistor.  They can not also be wired in series with each
other.
>
> BZZZT!  WRONG!  See above.
> Sheesh!  Such misinformation!
> Re: "LED's", see my .sig below.
>

What about putting in a voltage doubler or tripler and then
doubling or tripling the number of LEDs in series?

R

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From: "Roger Dewhurst" <dewhurst@NOSPAM.wave.co.nz>
Newsgroups: sci.electronics.components,sci.electronics.design,alt.engineering.electrical,aus.electronics,sci.electronics.repair
Subject: Re: Best way to power array of LEDs?
Date: Sat, 5 Oct 2002 08:26:25 +1200
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