[sdiy] Kawai K5m LCD backlight

[Tom Arnold]

On Sat, Aug 09, 2003 at 04:37:05PM -0500, David Cornutt wrote:
> Anyway: the inverter seems to be dead.  I tried re-heating the solder
> joints (some other people on Usenet have suggested this, and it
> did have one visible cold joint), but that didn't get it.  I haven't put
> a meter on it because I'm afraid of what voltage it might be (more than
> the 600V max of my meter), but since the thing doesn't squeal, I'm
> assuming it's dead.  The original part is no longer available.  So
> the question is: does anyone eise with a K5/K5m know what the
> inverter output voltage and frequency are supposed to be?  If I
> could find a substitute, I could kluge a way to fit it into the case and
> wire it to the power board.  Has anyone that has a scope with a
> high-voltage probe ever put it on a K5's backlight?

A little digging online should find you a nice EL power supply to use.
Remember that EL wire is the same basic stuff as the EL backlights.
All Electronics has typically had some small EL power supplies and you can
also find EL experimenters kits which is some cases even come with trimmable
EL sheets.

Something I've been experimenting with is front lighting.  Replace the
backlight with a reflective backing ( I've been using Bike shop reflective
tape stuck onto thin plastic ) and then put LEDs around a piece of lexan that 
you put in front of the LCD.  Works.  There are better things to use then lexan
of course, the plastic they make light pipes out of ( and maybe fibre optics? )
is available in sheets.  I have one chunk of this stuff 1/4" thick that I made
a sign out of and it works wonderfully.  I just made a thin circuit board and
put a bunch of surface mount LEDs on it to glue down 1 edge.

Nice thing about modifying for front lighting is its typically much more 
viewable under bright lights and in sunshine, important if you take your
gear to Burningman or something...

-- 
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 - Tom Arnold -       When I was small, I was in love,                  - 
 - Sysabend   -       In love with everything.                          -
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