electroluminescent displays

[eric schumacher]

Hi Group
The most common digital automotive displays are vacuum fluorescent
displays(VFD). They are typically green, but other colors are possible(its a
phospor). The tubes are manufactured by four companies worldwide: Noritake,
Futaba and Samsung (NEC has recently left the Business.) Complete modules
with drive electronics are made by a number of other companies.  To light
these puppies up it takes an AC filament voltage (between 5 & 10 volts,
depending on the width of the tube) and grid and anode voltages. Grid &
anode voltages are typically between 40 & 60 volts DC depending on the
number of grids.  The number of grids determines the multiplex ratio hence
the voltage. There are lots of drivers on the market from guys like Supertex
and Allegro (ex Sprague). It usually takes a microprocessor to run a typical
display. an 8051 will run a dashboard and a clock chip will run a clock with
no extra drivers, that is kinda the range.  The big problem with these
things is that if you want a custom pattern (like in a VCR) it is big bux
(approx 35 grand) If you can get your hands on a panel you like it is not
too unreasonable to build the drive electronics yourself, however The best
way to get there is a full graphics panel then all is software. All the
cutsy icons and such come for free.  As long as you don't want too much area
it is affordable.

To change the subject a bit perhaps the best technology for an custom dash
is electrolumniscent, available from Planar in Beaverton OR. It is very wide
in temperature range unlike graphic LCDs, and is a very high contrast and
crisp amber>A
Lotsa Luck Eric
85 GTI with VR6 power