Re: TI-H: LCD problem

To: <ti-hardware@lists.ticalc.org>
Subject: Re: TI-H: LCD problem
From: "David Knaack" <dknaack@easen.net>
Date: Tue, 24 Feb 1998 16:32:54 -0600
Reply-To: ti-hardware@lists.ticalc.org

From: PXGray@aol.com <PXGray@aol.com>
>Yea, I think using a strip such as the Timex Indeiglo thing would work a
lot
>better than the current TI-Glow.  The trouble is, finding a big enough
strip
>out of existing hardware, or building one yourself.  That would be a good
idea
>if someone could do it though.  It might suck through batteries real fast
>too...


I already replied to this, but I just located some more info, heres the
gist of it:
The electroluminescent lamps come in several standard colors (Yellow,
Aviation Green, Blue-Green, Blue, and Violet), a couple dye modified
colors
(White, High-Visibility Green (chartreuse)), and some custom colors,
obtained
by placing a filter over the lamp.  The drive circuit is AC, normally
ranging from
about 40 volts to 140, at frequencies between 50 and 800 Hz.  Standard
operation
is at 115 volts 400Hz.  Under standard operation, the lamps draw about 1mA
per
square inch (for a TI-85 display that would be around 5mA, not much of a
load at all).
DC-AC inverters for battery operation are available.
The edges of the displays are sealed out to about 2mm, to prevent damage
due
to humidity (the single largest contributor to shortened lamp life).

I am pricing a lot of 20 and a single panel custom sized for the TI-85 in
Blue-Green
and White (Blue-Green is cheaper), with 6V DC-AC supplies.  I will post
the price
when I have it, would anyone be interested in purchasing displays through
me
(assuming the price is reasonable of course)?  I'm not looking to make a
profit, just
to distribute the cost of any initial tooling that may have to be done to
produce a panel
of the right size. I would ship displays at cost, plus postage and a buck
or 2 for my trouble.

In the meantime, if anybody wants to try and turn a nightlight into a
backlight, be
sure to seal the edges if you have to cut the panel! :)  My guess is that
those nightlights
don't have any drive circuitry at all, and are just built to run at 115V @
60Hz (0.8W?).

later
David Knaack