Oops, this time with a topic tag.  Sorry

I have googled myself blue, but I can't seem to find a decent application
note for "putting the juice" to this display.  At US$40.00 each I would
prefer not to boil the substrate, so I need some clarification on the LCD
contrast voltage.  The data-sheet that I found shows the supply voltage for
the contrast pin as Vdd-Vee 18.5 to 19.5 volts.  I am fairly sure that the
contrast "really" uses a negative voltage.  Are they trying to say that Vdd
*minus* Vee should be in this range 18.5 to 19.5 volts.  So by my
calculations this works out to be 5V - (-14V) = 19V.  So I think that my
contrast voltage should be in the range of  -13.5V to -14.5V  Does this
sound correct to everyone???  The really interesting part of the data-sheet
is in the Absolute Maximums box.  It plainly says that the maximum Vdd - Vee
is 2480V, is this for real????

This display uses a "cold cathode" type bulb for the back light.  I made it
light up today and didn't even let any smoke out.  ;-D  I used a little
12VDC to High-Voltage AC.  I'm not sure exactly what the voltage is when the
backlight is lit, but I my meter says 810V.  Is my relatively cheap digital
volt meter lying to me?  Since the AC voltage is being supplied from a
converter, I assume it is at a high frequency (like maybe in 50Khz
range???).  Would this make my volt meter reading way off since the AC is
not at 60Hz?  800V seems a little optimistic for this tiny little converter.
The converter is made to run beautifully colored "cold cathode" bulbs, but
the bulbs I have seen used are probably twice the length.  They now have
some shorter "colorized" bulbs and are recommending the same converter for
them.  I am just worried that I am going to burn out the back light with
extended usage.  The datasheet specifies a nominal voltage of 300Vrms and a
max of 350V.  The absolute max is 1500V.  Should I be looking for (or
building) another converter?  Help me, please, before I elexamacute myself
or worse.  ;-)

--
Michael Brown
Instant Net Solutions
www.KillerPCs.net

"In the land of the blind, he who has one eye is king"

--
http://www.piclist.com#nomail Going offline? Don't AutoReply us!
email listserv@mitvma.mit.edu with SET PICList DIGEST in the body