Martin that sound like a way to make a lot of money and I think a good 
cowboy should take on the job.  Then you could ask your old classmate to 
help out with the testing.  Smile.
----- Original Message ----- 
From: "Martin McCormick" <[log in to unmask]>
To: <[log in to unmask]>
Sent: Friday, October 14, 2011 12:03 PM
Subject: Re: talking v. o.m.


I am surprised that nobody has come up with a talking
VOM that could also give an analog style indication. What I am
thinking of is a talking multimeter that gives you the numerical
values that one needs as well as a tone that rises and falls
with the readings. It wouldn't be that difficult especially with
digital circuitry. One could listen to the tone and get a rapid
indication if some value was rising or falling and then push a
button or whatever to call for a quantitative readout.

Another way to do that is with a VCO or Voltage
Controlled Oscillator. There are several VCO IC's out there but
one would want one with a large range so that you could hear
small changes more easily. It would have to be just in front of
the analog-to-digital converter circuitry so that it would work
on all ranges.

Most of the analog-to-digital converters I have studied
work on a 0 to 5-volt range. One extreme gives you the maximum
output number as in all ones and the other extreme gives you all
zeros.

Some of the PIC microcontrollers have A/D converters
with a 1024-bit resolution which could make for a pretty good
meter as long as it stays accurate.

Martin McCormick WB5AGZ  Stillwater, OK
Systems Engineer
OSU Information Technology Department Telecommunications Services Group