Reply-To: "Dave M"
From: "Dave M"
References: <email@example.com> <firstname.lastname@example.org>
Subject: Re: Digital Meter Scaling Question
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Date: Thu, 10 Oct 2002 23:52:23 GMT
NNTP-Posting-Date: Thu, 10 Oct 2002 23:52:23 GMT
Organization: AT&T Worldnet
Pardon me for coming into this thread at this late time, but there is
something wrong with the OP's details. He states that the DPM is a Datel
model DMS-30PC-0-BS, and has a +/- 2V full-scale range. I took the time to
download the spec sheet from Datel, and according to it, that model number
is, in fact, a +/- 200mv full-scale meter. Am I missing something??
If the model number is correct, and the spec sheet is correct, I would check
to see what the full-scale voltage range of the DPM really is. Take the time
to hook it up as a voltmeter, and using a power supply or battery monitored
with a separate DVM, see what it reads. If it is actually +/- 2V, then the
unit is apparently marked incorrectly and should be returned for a unit with
the correct range.
Dave M email@example.com
Remove the xx for my correct email address
"Tom Faloon" wrote in message
> The solution to your question may seem simple in principle, (it's just a
> inverting OP Amp, and it could be knocked together in ten minutes) but
> chances are, the results would be disappointingly inaccurate. It needs
> careful component selection and design, and this depends on your
> requirements. You won't get the help you want unless you specify the
> requirements. (No guarantee even then, since it may take several hours
> Newsgroups are great for quick answers to specific questions, with 5
> answers, but your problem raises a host of questions, and few folk will
> the time, or inclination to do your design for you.)
> So, help someone to help you. You need to answer the following, at least
> begin with.
> What % accuracy do you want?
> What is the source impedance of the voltage to be measured?
> Will the system be battery operated, (If so, the amp may need to draw low
> If used, is the battery voltage/type important?
> If not battery operated, what power supplies are available, or what would
> you like to use?
> What is the temperature range you intend to use it in?
> Is cost important?
> Do you already have one or more preferred OP Amps in mind?
> What is the panel meter part number? and where can one find a data sheet.
> (I know you specified that already, but few folks are going to plough
> through a dozen messages to find it! Put it all on one page, and hope for
> Tom Faloon
> The meter I am using is a 5 volt LED panel meter. The part number is Datel
> DMS-30PC-0-BS. The datasheet is available at www.datel.com.
> Ed Edmondson wrote in message
> > I really still need your help? Anyone have any amp suggestions?
> > Thanks,
> > Ed
> > Ed Edmondson
> > Alamosa, CO
> > firstname.lastname@example.org