Hi Finn.

The pressure transducers I have can measure from memory a differential pressure of about 40” of water.
They have a millivolt output and in the process of cooking up a set of amps and thinking about the fact that Ive used up all my Engine Monitor inputs I pondered all those unused EGT and CHT inputs with amplifiers for millivolt input.
I thought about the thermocouple compensation, impedance matching and common mode currents from the egt amps (don't really have a handle on these) and decided I probably wouldn't damage them!
So I just thought Id try it out.
I wired one straight to an egt input and the Dynon 5v supplied, and applied some lung pressure and the dynon display showed some life.
I reworked a new Polynomial and she seems to provide a linear output over my lung burst pressure which from memory is a little over 1 psi.
I’m not after certifiable numbers but have built a manometer to hopefully roughly calibrate the output by playing with the Polynomial.
So lots of ignorance as far as what’s happening with the electrons at the interface but the results look promising and could be so much more helpful and easier than rigging a manometer in the cockpit.

Happy to have my party spoilt by someone with knowledge of the compensation circuit used in the EGT amps.

Cheers

Steve






> On 7 Aug 2020, at 11:01 pm, Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net> wrote:
>
> On 8/7/2020 10:00 AM, Stephen Izett stephen.izett@gmail.com wrote:
>> I worked out that they interface quite nicely without any other circuitry with the Dynon Skyview's surplus EGT inputs via a new Polynomial in the sensor config settings.
>
> I'm thinking of using my unused?? EGT inputs for current (Hall) sensors.
>
> How did you compensate for the EGT compensation?
>
> Finn
>
>
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