Hi guys, I'm thinking about this... Construct a circuit to control a peltier. The circuit will have two thermistors, one for the peltier, and one to measure the room temperature (or rather case temperature). The circuit will control the voltage supplied to the peltier so that the cold side of the peltier will always remain at room/case temperature. Thus there will be no condensation. Possible? Any repercussions to consider? TIA.
If I were to do this, I'd not use a thermistor. There's quite a few IC's out there that measure the temperature, or even just a simple 1N4001 diode used as a temperature sensor (very effective).
The major problem is siting the peltier probe where it actually measures the cold-face temperature. For that reason a thin-film type thermistor will probably be better than the more accurate but bulky semiconductor sensors. You can try to fix the probe tip against the cold-face, between ceramic surround and peltier (not between core and peltier )
I figured I would probably need a copper cold plate between the peltier and the core, thus I just need to measure the copper plate's temperature.
yes, couldn't he just drill a little hole in the side of the cold plate and put his thermister there?
I have been wanting to do this for a while, The hard part is that you need to make an adjustable CURRENT power supply. Which is much harder than adjusting the voltage to the peltier. I tried an adjustable voltage power supply to regulate a peltier, but when the voltage changes the current REALLY increases, this is due to the fact that the peltier uses P/N Junctions. The same as a whole ton of diodes in series. This causes sharp current changes when voltage is changes. After the holidays I will try again.
