Re: Damned Projects!

Don <g@crcomp.net> wrote:

Electrolysis can cause the DC sensor to degrade over time. An analog
adaptation from resistance to capacitance can curb this effect. The
above sensor needs to be altered to detect a dielectric difference
instead of an ohmic resistance.

Perhaps spme sort of adaptation of my conductivity meter circuit would
do the job:
<http://www.poppyrecords.co.uk/other/ConductivityMeter14.gif>

It generates floating AC with prevents electrolysis at the sensor and
uses synchronous rectification to eliminate spurious responses.  For
simplicity, the range switch could be replaced by a pot and the meter
drivers arranged to switch a relay.

--
~ Liz Tuddenham ~
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www.poppyrecords.co.uk