Re: TI-H: Backlight
[Prev][Next][Index][Thread]
Re: TI-H: Backlight
I just use standard 1/8" thick plexiglas from a common hardware store.
I use 6 Yellow superbright LEDs from all electronics #1-800-826-5432. I
connect them as shown on my page
(http://www.geocities.com/SiliconValley/Lakes/5081/Richfiles.html).
I sand the plaxiglass verticaly, at a barely noticable angle. If it's
too horizontal, the scratches light up. I would sand both sides and only
verticaly. Back may be ok at just a few 1-5 degrees. not much.
A roll of electrical tape should elevate the bottom side of the LCD
about 1/2 to 1 mm so it's at an angle. This helps reflect the light.
The LEDs simply have wires running to the ground and the other to a
switch, which then connects to the (+) terminal. A very small value
resistor should be used. Only as protection. The batteries just have
enough power to run it. It gets a little dim at around contrast 5
(backlights use a LOT of power, which is why notebook computers run
longer when you turn the backlight down). You can also build the battery
extender on my page. Use at least a 100 ohm resistor especialy if you
build the AC power pack. Use the 6v, 100 ma pack from all electronics.
$2.50 and lower power is easier on the LEDs. The resistor will need to
be VERY LOW. I suppose a 100 ohm resistor will work. If you want a
variable resistor, you'll need to try it. I have not done it yet.
shouldn't be any problem. Maybe I'll try it soon.
Richard Piotter
richfiles1@hotmail.com
>
>
> Okay.. I just ripped my TI-85 apart to make the backlight..
everything
>went well and I have the mirror LCD and everything seperate and all the
>sticky stuff cleaned. Now I just need to add the plexi-glass and
LED's..
>That's where my questions come in.. Do I need to use Plexi-glass??
How bout
>a very thin piece of Mylar? or is having it too thin a problem? If so
>what's the best size plexi-glass?? Also in what way do I sand it? Up
and
>down, Left and right, or circular? And what's the best type of LED's
to
>use.. I've heard Super-Bright Yellow LED's.. should I use standard
size
>LED's or mini-LED's?? and what is the best resistor value? Or should
I just
>use a varible resistor? If so what value should the varible be? And
last
>but not least.. in what way do I like the LED's together to the power??
>Ohhh.. and how many LED's are best? Anyway.. any comments would be
HIGHLY
>appreciated.. thanks a bunch guys..
>
>Pellaeon
>http://surf.to/pellaeon
>gramps@wf.net
>
>
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com