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Re: Ok, so let's plug in the numbers I worked on yesterday

Peter...

For such a small temperature difference, won't the seebeck coeff be near zero? That would mean all the energy there is dissipated..

I ran calculations for energy introduced by piezoelectric effect, motor generator effects, and skin effect storage collapse effects, and found the easiest was to use energy in joules. I didn't post that info as Jon and I have disagreements on those effects, and I won't post the info while he's down and out..

So that would be 1.5e-7 times 5e-5, or 7.5e-12., 7.5 picojoules.

You used 1 mm squared, which is about #16 awg, 4.3 ohms per 1000 feet, 4.3 e-3 ohms/ft., 3 feet is 12.9 e-3 ohms, 1.3 e-2 ohms.

The resistive loss in the entire cable is IRR,
I is: 600 ohm, 30mv, is 3e-2/6e2, .5e-4, or, 5e-5 amps

5e-5 * 1.3e-2 *1.3e-2 is 8.45e-9 watts

Times 5e-5 equals 42e-14, 4.2e-13 joules..

Hmmm that's not right, 7.5e-12 is larger than the cable loss..

Oh, wait a minute, the peltier loss has to be referred to the load dissipation, 600 ohms, 30mV.. so we don't care what the cable joule loss is..

Power=3e-2 volts times 5e-5 amps, , or 15e-7 watts, 1.5e-6 watts.

Energy dumped into the load per half cycle is.. 1.5e-6 times 1e-4, or 1.5e-10 joules (we are referring the loss per cycle, I assume only the front edge contributes to loss.

To be 120db down, the loss due to peltier(or anything else for that matter, needs to be about 1.5e-16 joules.

you calculated 7.5e-12 for peltier dissipation (I assume no return of energy here)..that is 5e4 larger than 120 db down..

Without accounting for energy return, the loss would be way too high for reason..It can't be that high..but I can't see the energy being returned very easily.

What are we calculating wrong?? Check mine, I'll check yours..

Should I be using the sqr of 120 db down, or 1000? That would make it 5e1, or 50 times larger than 120 db down?? That's at least within two orders of magnitude away from the measurements, but still on the high side..

Cheers, John


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