FW: [Elecraft] K1 LCD Illumination mod

Dan Barker [email protected]
Tue May 14 08:46:01 2002


They don't have to be Light-Emitting diodes. You can use plain diodes to =
drop .6 volt each. I guess the dissapation would be the same as a =
resistor, tho. You guys thinking of putting these accross 12V? I imagine =
there's 5V running around in a K1 (I've got a K2, so I can't look it up =
as easily). Maybe you'd be able to "discard" only 30% as much "extra" =
light and/or heat (or the heat comes out in the regulator? Doubt it.).

Dan / WG4S / K2 #2456.



-----Original Message-----
From: [email protected]
[mailto:[email protected]]On Behalf Of John J. McDonough
Sent: Tuesday, May 14, 2002 8:24 AM
To: [email protected]
Cc: Tom Hammond N=D8SS
Subject: Re: [Elecraft] K1 LCD Illumination mod


----- Original Message -----
From: "Tom Hammond N=D8SS" <[email protected]>
Subject: Re: [Elecraft] K1 LCD Illumination mod


> If you placed several of them in series, you could add up to about =
8-10
> LEDs with NO increase in current, and you'd not have to dissipate =
nearly
as
> much heat in the dropping resistor.

Actually, that had crossed my mind.  I've never been all that =
comfortable
with bunches of LEDs in series, but you use the same current, it's just =
that
you spend it generating light rather than heat.

Depending on the color, I think you are talking more like 4-6 or so, you
will want some sort of current limiting resistor I think.  But between =
the
number of LEDs and the resistor, you can kind of choose how much current =
you
want to spend, tho it will probably be between 10 and 20 mils.  =
Mechanically
arranging a half-dozen LEDs could be a bit of a challenge, though.

72/73 de WB8RCR    http://www.qsl.net/wb8rcr
didileydadidah     QRP-L #1446 Code Warriors #35

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