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From: "C what I mean" <"NO SPAM"@yahll.com>
Subject: Re: Best way to power array of LEDs?
X-Newsreader: Microsoft Outlook Express 6.00.2600.0000
NNTP-Posting-Date: Fri, 04 Oct 2002 12:53:09 GMT
Organization: AT&T Broadband
Date: Fri, 04 Oct 2002 12:53:09 GMT
No one asked what kind of LEDs. Some of the Lumileds LEDs draw up to 500ma
each! The newer ones can reach 750ma consistently. I doubt anyone would
use them in a car brake light.. but they are out there and used a lot......
for other applications of course.
"Jerry G." wrote in message
> Each LED must have its own series resistor. Most of these LED's work
> at about 30 to 40 ma with about 1.6 VDC across them. You should be able
> to use a 320 ohm 1/2 watt resistor in series with each LED if these are
> in the spec range that I used as an example.
> 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.
> Jerry Greenberg GLG Technologies GLG
> WebPage http://www.zoom-one.com
> Electronics http://www.zoom-one.com/electron.htm
> Instruments http://www.zoom-one.com/glgtech.htm
> "DaveC" wrote in message
> Have assembled an array of LEDs for use as a 3rd brake light in my car,
> configured as 4 rows of 9 jumbo LEDs, as of yet unwired. Of course the
> supply will be 12 volts nominal (13.8 volts, maximum).
> My options, as I see them, are:
> 1) Wire individual resistors to each LED based on its operating current
> 2) Wire each row in parallel and connect one resistor based on operating
> current for 9 LEDs
> 3) Install voltage regulator to output voltage (ie, 1.3 volts?) to
> all LEDs in parallel.
> What is the best method to power these from an intermittent (whenever I
> the brake pedal) power source?
> Other options for powering this array?
> Note that my return address is corrupted in an attempt to reduce spam.
> If you
> choose to e-mail me, please correct my address as described below.
> Dave Carpenter
> Sound Logic
> Remove the numbers to reply via e-mail
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