Hi,
I’ve noticed that many people have succesfully used / are using peltier module as a night cloud detector. After several test I got some questions and start to think whether it could actually be used as a solar sensor too.
At the moment I set it up with simple opamp to have a output voltage of milivolts converted to something I could measure more reliably and with a higher amplification the output is changing nicely even when an open palm is half a meter away from the module.
For the night cloud detector I assume bottom and top plate should be facing ground / sky.
I have used a sigle supply rail-to-rail opamp and this is probably not good as for the night cloud the module should indicate slightly positive or negative depending whether bottom or top part is radiated more. The question is, how did you got the readings into WD?
Looked at 1-wire and DS2438 voltage A/D could possibly be used, but from the datasheet it appears as it can only handle voltage of one orientation, i.e. negative volatge when other side of the module would be heated could be a problem. Did anyone connected it to 1-wire?
I think the best place for such sensor around my house would by at the part of the house that is constantly shadowed while it does offer open sky view. Any particular recommendations about the good location?
Secondly I thought whether current setup (ie. amplified readings when top part of the module is getting warm) could be an alternative solar sensor too.
Anyone tried this??
I’m little worried though whether a meaningfull output could be obtained this way. The module is very responsive to sun and it peaks quickly but after a while the value goes down to settle. I think this is because the whole peltier module gets heated so the temp gradient between the top and bottom gets lower than it has been initially.
The bottom part of the module should be at ambient temperature and I think it could improve if I attach a solid pece of copper or a passive PC cooler, but have my doubts whether this will be sufficient and the readings could be reliable. #-o
Looking forward to hear about your experiences so that I can come up with a good design! 