[time-nuts] Lead acid battery noise levels
ed breya
eb at telight.com
Thu Jul 11 12:39:54 EDT 2013
Third attempt at emailing again:
NiCd batteries should have the lowest noise for their size due to low
resistance, but if you look at ever-lower frequency, the Hg should be
superior since it has the most stable voltage with time and
temperature. Drift (including self-discharge) and temperature
variation response can appear as very low frequency noise independent
of the other noise sources and operating conditions. Hg batteries are
so stable that they were commonly used as voltage references or to
power small circuits without any additional regulation needed.
Ed
>Mike Feher wrote:
A long time ago, when I was concerned about a phase noise issue, I found an
old NBS article. It was on measuring phase noise and included a schematic of
an ultra-low noise amplifier. In that amplifier they used Mercury batteries.
I also glanced at the referenced article, stating NiCad is the lowest noise,
and, NiCads were available for a long time, yet they used Mercury. Regards
- Mike
>
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