Re: TI-H: backlight question.. (everyone, read it)

To: <ti-hardware@lists.ticalc.org>
Subject: Re: TI-H: backlight question.. (everyone, read it)
From: "David Knaack" <dknaack@geocities.com>
Date: Tue, 2 Jun 1998 15:37:20 -0500
Delivered-To: ti-hardware-outgoing@towerguard.unix.edu.sollentuna.se
Reply-To: ti-hardware@lists.ticalc.org


From: KrazyJolt@aol.com <KrazyJolt@aol.com>
>I'm in the middle of installing my EL into my calc.. suddenly i
realized that
>i don't really want to mess up the happy black case to install a
switch.  Then
>I remembered a suggestion to use a multimeter and find a spot that
has 6v+
>only when the calc is on.

I've been meaning to do this for a while, but haven't gotten around to
it yet.

> I would do that except for one pissy little
>problem:  i can't figure out a good way to NON-PERMANENTLY attach the
battery
>to bother the spring and that little square patch of metal...


You mean just to power the calculator while you poke around to try to
find
a good location??  If so, that is pretty easy, get some 'gator clips,
you can
get a package of about 10 at Radio Shack for a few dollars.  Install
the
batteries into the battery case (while removed from the calc).  Place
a couple
of pieces of wire or metal (delaminated transformer cores work great!)
into
the battery case where the wires from the main board would have gone
if
the case were put together.  Then just run you 'gator clips from the
main board
over to the battery case.

Alternately, you can use a wall power supply with the wires stripped,
or
any 6v supply.

When you find a place for the signal, I would recommend running the
base
of a transistor from it, rather than attempting to run the inverter
directly, as
the inverter may draw more current than the circuit you use is
designed for.

DK