>> It was also not the display I have in my other digital voltmeter
>> (Dynamco, I think) which has as digits a multilayer Perspex sandwich.
>> Each perspex layer has a dot pattern for a character drilled in it; you
>> light up a character by illuminating the edge of the appropriate perspex
>> wafer, and total internal reflection confines the light to that wafer,
>> thus lighting up the dot pattern of only the one character. Neat.
>
> I've seem those used with a 2-colour (black, or illuminated red)
> background for +ve or -ve results. Problem is, I can never remember if
> red is +ve (as an engineer would use) or -ve (as an accountant would
> use)... Actually, didn't Dynamco do that on some of their voltmeters?
IIRC my Dynamco uses red for negative.
Philip.
Received on Tue May 12 1998 - 07:05:30 BST
This archive was generated by hypermail 2.3.0
: Fri Oct 10 2014 - 23:31:12 BST