[volt-nuts] Homebrew DVM

Randy Evans randallgrayevans at yahoo.com
Thu Nov 10 16:20:58 UTC 2011

8.5 digits with averaging.
I did consider that but the ADCs I am familiar with only have a 5V input range so range resistors would be required, not desirable for me.  Also, they won't directly take the 7.2V ref input from a LTZ1000.  Plus the AN-260 circuitry is not too complex.  Otherwise, I agree with you.  

From: Poul-Henning Kamp <phk at phk.freebsd.dk>
To: Randy Evans <randallgrayevans at yahoo.com>; Discussion of precise voltage measurement <volt-nuts at febo.com>
Sent: Thursday, November 10, 2011 7:51 AM
Subject: Re: [volt-nuts] Homebrew DVM

In message <1320939951.98248.YahooMailNeo at web37902.mail.mud.yahoo.com>, Randy E
vans writes:

>My hope is that the DVM will be able to measure to 8.5 digits [...]

Do you mean 8.5 digits single-shot, or 8.5 digits with averaging ?

Considering that you can get off-the shelf ADC's where 24 bit is routine
and 26 bits available, I'm not sure I'd bother...


Poul-Henning Kamp      | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG        | TCP/IP since RFC 956
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Never attribute to malice what can adequately be explained by incompetence.

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