-=> Mike Ross said to Greg Mayman
 -=> about "HVDC TRANSMISSION LINES" on 01-15-03  21:47.....

 MR> I'm thinking that maybe in the heat of a car dashboard it could be the
 MR> driver circuitry that may be stalling as the transistor leakage
 MR> currents rise. We know LCD's go black if the backplane isn't fed with
 MR> an AC bias. 

I've had a couple of LCD clocks that died in the heat of a car.
They didn't recover at all.

OTOH, it may have been the driver or other parts that suffered
the permanent damage.

OTOH I've never had an LED or fluorescent display auto clock die
from the heat, and they have all been (a) in black cases and (b)
mounted on the top of the dash where they can get the direct sun,
so they would get really tremendous heat build up, much more than
the LCD clocks which were attached with double sided tape on the
front of the dashboard away from the direct sun.

OTOH they _were_ made for auto use. The LCD clocks were just
general purpose ones.

Hmmm... that makes four hands... I guess this message is turning
into a piano duet 

 MR> This happens accidentally for example if one forgets to turn off a DMM
 MR> and the battery dies overnight, in the morning the LCD will be
 MR> stained. Some of the stain goes away but some of it remains.

I've seen that, but never realized what caused it.

From Greg Mayman, in beautiful Adelaide, South Australia

... It's always darkest just before you step on the cat.
___ Blue Wave/386 v2.30

--- FLAME v2.0/b