Pulse Measuremen​t without a digitizer-​Is this doable ?

Question

I have the need to measure a pulse in the 100ns range.
I can control the voltage level that I feed into the circuit.
I would like not to have to use a digitizer card (scope).
Would this be possible with a simple voltage divider into a comparator
circuit and the PCI MIO E-1 data aquisition card ?
My concern is with the slowness of the card and whether I will be able
to accurately capture the pulse measurement.
I am using Labview 6 as the software environment.
Thank you for any suggestions.
Rick Barry
Manufacturing & Test Engineering
Warner Power LLc

Answer 1

On Sun, 30 Jun 2002 10:06:36 -0700 (PDT), Labviewguru
wrote:
>Rick,
>
>I think you are trying to measure the voltage (please let me know if
>not). As the time resolution of the PIC MIO 16E-1 is 50ns at best,
>you obviously can't measure the voltage of this pulse very accurately.
>
>What I believe you need to do is to use some (I think) simple
>electronic circuitry to condition this pulse peak (is that what you
>are trying to measure?) to a constant voltage. The exact nature of
>the circuitry is highly dependent upon the exact measurement that you
>want to make.
>
>There is of course another option. If you think outside the box,
>literally (outside of the computer case), you can consider using other
>hardware for your measurement. If you have a high speed scope that
>can make the measurement (I assume you have that equipment, as you
>described the signal fairly well), then all you need to do is capture
>the measurement with the scope, and bring it into LabVIEW for analysis
>and processing. There are a number of ways to do this, including
>GPIB.
>
>Please clarify the measurement you are trying to make, and the
>equipment you have and its communication capabilities.
Thanks so much for your answer.
Yes, voltage is the key here, but not just a peak, frequency is also a
needed parameter.
Currently, measurements are taken with a scope and a high voltage
probe. The circuitry you describe has not turned out to be all that
simple, at least I have not found a simple way to do it. I have tried
voltage dividers and comparators, but of course, I then sacrifice
resolution to the point of the readings being meaningless.
I am trying to take the scope out of the picture for both cost and
simplification reasons. I have found a way to eliminate the high
voltage probe from the picture but was hoping to also find a way to
remove the need for the scope and/or digitizing card.
The actual pulse is between 24 & 30 KV @ a frequency of 20 mHz.
With a custom designed pick up coil, I have managed to get an
excellent "picture" of this in the 60 volt range @ 50ns. Much more
workable than the high voltage. No sacrifice in resolution either.
Can you recommend anything that would capture this into Labview for me
Thanks again.
Rick Barry
Manufacturing & Test Engineering
Warner Power LLc
Rick Barry
Manufacturing & Test Engineering
Warner Power LLc