Re: TI-H: LED Backlight

To: <ti-hardware@lists.ticalc.org>
Subject: Re: TI-H: LED Backlight
From: "David Knaack" <dknaack@geocities.com>
Date: Wed, 27 Jan 1999 17:48:25 -0600
Delivered-To: ti-hardware-outgoing@towerguard.unix.edu.sollentuna.se
Delivered-To: ti-hardware@lists.ticalc.org
Reply-To: ti-hardware@lists.ticalc.org


From: Chris Cooper <cooper@fort-frances.lakeheadu.ca>
>I still don't know what the big deal is, 
<snip snip>

I agree, my 85's are no problem to see, not as good as the
original, but no problem at all.  What I'm saying is that if this
guys 92 screen is pretty bad to start with, adding a backlight
certainly isn't going to HELP matters (except in dim lighting
conditions of course).  

>BTW. How are the new EL auto-on plans coming?


I haven't had much time to work on it actually.  I was planning
on working on it tonight.  I was distracted by some other
calculator work and a few movies (BTW, don't bother renting
'Fear and Loathing in Las Vegas', its mostly boring).  I have
some reading to do on the new method I want to try, I think I can
reduce the part count quite a bit (hopefully to one :).

In the meantime, if anyone wants to use the current version it
will work just fine if the first stage of the output is replaced with
a darlington (dropping the second stage of the output) and the
inverter is moved to the collector (instead of its current position
in the emitter).  That reduces the part count to 4 and simplifies
the PCB.

later
DK

Follow-Ups:

Re: TI-H: LED Backlight

From: Grant Stockly <gussie@alaska.net>

Re: TI-H: LED Backlight

From: Chris Cooper <cooper@fort-frances.lakeheadu.ca>

Re: TI-H: LED Backlight

From: Olle Hedman <oh@hem.passagen.se>