[volt-nuts] Traveling Standards - pictures + protocol

[WarrenS]

Bob

Another thought.
Soldering plastic voltage reference parts to a PCB can also cause stress 
problems.
Part of your high resolution testing should be to Flex the PCB board a 
little in both axes.
Then push and tap on the top the parts a little to see what happens.
I've seen some parts work better as a strain gain than a voltage reference 
when mounted to a PCB.

ws

****************
Hello Bob,

one thougth of me just seeing the pictures.
how is the "top" and "bottom" of LM399 stabilized with your tube package.

Even when top and bottom is defined. The tube can be tilted by around 45 to
90 degrees.
Did you check if that has an influence on the output voltage?
Is the PCB fixed within the tube?

> Thanks Fred.  Both references (the LM119AH and the MAX6350) have several
> hundred hours on them.  I have left them on for all the time since I put
> together the first bread board.  When I was not working on them, they have
> been powered.  They will accumulate an additional hundred hours or so
> before I actually ship them.

At least the plastic case of the MAX6350 will have suffered from soldering.
(dryed out).
So it will take at least a week or two until the unit has again stabilized.

With best regards

Andreas

----- Original Message ----- 
From: "Bob Smither" <smither at c-c-i.com>
To: "Discussion of precise voltage measurement" <volt-nuts at febo.com>
Sent: Tuesday, September 06, 2011 7:04 PM
Subject: Re: [volt-nuts] Traveling Standards - pictures


>I finally found time to post some pictures of the TS:
>
>   http://c-c-i.com/image/tid/2
>
> -- 
> Bob Smither, PhD                                 Circuit Concepts, Inc.
> =======================================================================