Path: utzoo!attcan!uunet!zephyr.ens.tek.com!uw-beaver!ssc-vax!uvicctr.UVic.CA!climber
From: climber@uvicctr.UVic.CA.UUCP (climber)
Newsgroups: sci.electronics
Subject: Logic level detectors
Message-ID: <957@uvicctr.UVic.CA.UUCP>
Date: 13 Mar 90 18:45:22 GMT
Distribution: na
Organization: University of Victoria, Victoria B.C. Canada
Lines: 10

Hi there.  I am building a multi-line logic level detector that has two
leds one that lights on logic level 0 and one that lights on logic level 1
and neither are lit if the line is 'floating'  (such as an output to a ram
chip that is not selected).  I currently use p channel FETS with a large
resistor to detect logic 1 without drawing too much current (and possibly
affecting the circuit).  Question: can I use n channel FETS in more or less
the same manner to power an LED on a logic level 0 (and it still would draw
very little current)?

Craig