Article View: sci.electronics.components
Article #122Re: Best way to power array of LEDs?
From: Winfield Hill
Date: Thu, 07 Nov 2002 12:20
Date: Thu, 07 Nov 2002 12:20
105 lines
6733 bytes
6733 bytes
>>> Winfield Hill wrote:
>>>> I was taught to make efficient designs by insuring every part
>>>> has a purpose and carries its own weight. With that in mind,
>>>> here's my entry, a slim 32-channel adjustable current source.
>> ehsjr@bellatlantic.net wrote...
>>>
>>> Where's the remote current sensing/ individual current
>>> auto-adjusting circuit for each LED?
> Winfield Hill wrote:
>> Oh, sorry, I've fixed it now.
Clifton T. Sharp Jr. wrote...
> So where's the polarity-reversal mechanism to change the color
> from red to green? :-)
I apologize for leaving that important feature out. Now fixed.
> 12V etc
> | 4.7k 68 2W gnd
> +---/\/\----+--- E C --/\/\----+--------------,
> | | B | -Vref |
> |LM385-1.2 B | 3.3k | | |
> +--|>]--- E C ---x----/\/\-----' LED color | |
> | | control | |
> | | LED, two-pin | | | |
> | | N-FETs two color | | | |
> | | \ ,---\--------+----|-+ | | Imon
> | | \ | ,-\------XX--+-|-|----|--|--o
> | B ,-XX--|--\--, | | | | |
> +-/\/\-+- E C -+ +-|>|-+ +-|-|-/\/\--+
> | | | '-XX--+-|<|-+--XX--' | | | |
> | \ | |____________|____| | | |
> | / | pd | | | |
> | | | ,--||---+-|>|--, | | | |
> | | | | /-|-+------|--/\/\-|-|----+ |
> | '----|--+--< | | | | | |
> | | \+|--------+-------|-|----|--+
> | | | | | |
> | | ,------------+----|-+ | | Imon
> | | | ,--------XX--+-|-|----|--|--o
> | B ,-XX--|-----, | | | | |
> +-/\/\-+- E C -+ +-|>|-+ +-|-|-/\/\--+
> | | | '-XX--+-|<|-+--XX--' | | | |
> | \ | |____________|____| | | |
> | / | | | | |
> | | | ,--||---+-|>|--, | | | |
> | | | | /-|-+------|--/\/\-|-|----+ |
> | '----|--+--< | | | | | |
> | | \+|--------+-------|-|----|--+
> : : : : : :
> : insert 26 more stages here : : : :
> : : : : : :
> | | ,------------+----|-+ | | Imon
> | | | ,--------XX--+-|-|----|--|--o
> | B ,-XX--|-----, | | | | |
> +-/\/\-+- E C -+ +-|>|-+ +-|-|-/\/\--+
> | | | '-XX--+-|<|-+--XX--' | | | |
> | \ | |____________|____| | | |
> | / | | | | |
> | | | ,--||---+-|>|--, | | | |
> | | | | /-|-+------|--/\/\-|-|----+ |
> | '----|--+--< | | | | | |
> | | \+|--------+-------|-|----|--+
> | | | | | |
> | | ,------------+----|-+ | | Imon
> | | | ,--------XX--+-|-|----|--|--o
> | B ,-XX--|-----, | | | | |
> +-/\/\-+- E C -+ +-|>|-+ +-|-|-/\/\--+
> | | | '-XX--+-|<|-+--XX--' | | | |
> | \ | |____________|____| | | |
> | / | | | | |
> | | | ,--||---+-|>|--, | | | |
> | | | | /-|-+------|--/\/\-|-|----+ |
> | '----|--+--< | | | | | |
> | | \+|--------+-------|-|----|--+
> | | | | | |
> | | ,------------+----|-+ | | Imon
> | | | ,--------XX--+-|-|----|--|--o
> | B ,-XX--|-----, | | | | |
> +-/\/\-+- E C -+ +-|>|-+ +-|-|-/\/\--+
> | | | '-XX--+-|<|-+--XX--' | | | |
> | \ | |____________|____| | | |
> | / | | | | |
> | | | ,--||---+-|>|--, | | | |
> | | | | /-|-+------|--/\/\-|-|----+ |
> | '----|--+--< | | | | | |
> | | \+|--------+-------|-|----|--+
> | | | | | |
> | | ,------------+----|-' | | Imon
> | | | ,--------XX--+-|------|--|--o
> | B ,-XX--|-----, | | | |
> '-/\/\-+- E C -+ +-|>|-+ +-|---/\/\--+
> | '-XX--+-|<|-+--XX--' | | |
> \ |____________|____| | |
> / | |
> | ,--||---+-|>|--, | |
> | | /-|-+------|--/\/\--------' |
> '-------+--< | | |
> \+|--------+-----------------'
>
Thanks,
- Win
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X-Google-Language: ENGLISH,ASCII-7-bit X-Google-Thread: 112d1e,4ef4c9d4aea85e1f X-Google-Attributes: gid112d1e,public X-Google-Thread: 10d137,4ef4c9d4aea85e1f X-Google-Attributes: gid10d137,public X-Google-Thread: 103407,4ef4c9d4aea85e1f X-Google-Attributes: gid103407,public X-Google-Thread: 1131b0,4ef4c9d4aea85e1f X-Google-Attributes: gid1131b0,public X-Google-Thread: 1118be,4ef4c9d4aea85e1f X-Google-Attributes: gid1118be,public X-Google-ArrivalTime: 2002-11-07 04:50:49 PST Path: arc1-ca.pugleaf.net!archiver1.google.com!news1.google.com!newsfeed.stanford.edu!nntp.cs.ubc.ca!nntp-relay.ihug.net!ihug.co.nz!west.cox.net!cox.net!pln-e!spln!dex!extra.newsguy.com!newsp.newsguy.com!drn From: Winfield Hill <whill@picovolt.com> 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: 7 Nov 2002 04:20:43 -0800 Organization: Rowland Institute Lines: 106 Message-ID: <aqdlqr01vcm@drn.newsguy.com> References: <0001HW.B9C26E7400A7161B165FEAC0@news.covad.net> <Rsan9.14070$qh1.1622310@news.ca.inter.net> <ank9ep$lumv$1@hades.csu.net> <anku2n$5so$1@news.wave.co.nz> <7tGLdeAS6fn9EwBv@jmwa.demon.co.uk> <apvlvu$n2c$1@reader1.panix.com> <KVdHjAAjM3w9Ew8l@jmwa.demon.co.uk> <aq17gb$7ut$1@reader1.panix.com> <aq1ckv02qbk@drn.newsguy.com> <3DC6F8DC.CF94292A@bellatlantic.net> <aq7f2c01co0@drn.newsguy.com> <3DC93ECF.77E10699@clifto.com> NNTP-Posting-Host: p-634.newsdawg.com X-Newsreader: Direct Read News 4.10