[time-nuts] Voltage Standards

[Bruce Griffiths]

Brooke Clarke wrote:
> Hi:
>
> Geller's patent 7382179 Voltage reference with enhanced stability explains how 
> he combines the AD587 voltage reference with the LM399 voltage reference to 
> obtain improved temperature stability.  The method can be used with the LT1000.
> http://www.google.com/patents?id=v0GqAAAAEBAJ&dq=7382179
>
>   
However the instability of the AD587 internal resistor network and
buffer amplifier would significantly degrade the LTZ1000 performance.
> 7380471 Micro gust thermal anemometer is a similar circuit by Geller where the 
> LM399 is installed on the PCB using the untrimmed leads so that it's up in the 
> air.  Any wind changes it's temperature which is seen as an output.
> http://www.google.com/patents?id=GDuqAAAAEBAJ&dq=7380471
>
>   
There has to be a better sensor than an LM399 surely.
A sensor that isnt nominally temperature compensated should be better.
> I found a drawing on the National Semi web site for a Valox plastic shield for 
> the LM199, but there's not any other info about it or the specified material.
> http://www.national.com/packaging/mkt/h04d.pdf
>
>   
The original ones were polysulphone.
> Brooke Clarke
> http://www.prc68.com
>
>   
Bruce