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From: "Don" <g@crcomp.net>
Newsgroups: sci.electronics.design
Subject: Re: Damned Projects!
Date: Sun, 29 Dec 2024 18:27:35 -0000 (UTC)
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Liz Tuddenham wrote:
> Don 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.

Do the five Schmidt triggers in parallel after the oscillator act as a
buffer? This guy follows your example:

<https://www.electroschematics.com/simple-water-detector-circuit/>

All things considered, Wanderer's refractive sensor looks like the best
bet so far.

And now some comic relief for the artistic, mad man mentality; a Fritzed
555 AC water sensor:

<https://www.instructables.com/Capacitive-Sensor-Reworked-Wemos-With-555-Timer-Ba/>

Danke,

-- 
Don, KB7RPU, https://www.qsl.net/kb7rpu
There was a young lady named Bright Whose speed was far faster than light;
She set out one day In a relative way And returned on the previous night.