Re: TI-H: LED Backlight

To: ti-hardware@lists.ticalc.org
Subject: Re: TI-H: LED Backlight
From: Grant Stockly <gussie@alaska.net>
Date: Wed, 27 Jan 1999 16:11:10 -0900
Delivered-To: ti-hardware-outgoing@towerguard.unix.edu.sollentuna.se
Delivered-To: ti-hardware@lists.ticalc.org
In-Reply-To: <000c01be4a4f$88720c40$c9648ed1@vizzini.rdtech.>
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.

A 2N2222 will work fine.  It shouldn't use over 100ma.

References:

Re: TI-H: LED Backlight

From: "David Knaack" <dknaack@geocities.com>