I have a question about using peltier cells for both cooling and reading temperature in the same moment.
I need to cool down a couple of Integrated Circuits so I’ll put put a 20mmx20mm peltier cell over them but I cannot read the cold side of the cell because it’s sticked to the IC; I hope physics land me a hand here, providing I put a thermocouple to the hot side…
2. Relevant equations
S = - (Δv/Δt)
S is the Seebeck coefficient (which I’ll need for later)
Δv is the voltage I’ll read with a multimeter
Δt is thermodynamic temperature which I’ll read with a thermocouple. If I understood correctly it should be the difference between the hot and cold side expressed in kelvin’s degrees
I’ll take all these measurements before placing the peltier over the IC to avoid experimental errors
3. The attempt at a solution
Now that we found S we place the cell on the IC with some thermal compund and we get:
Δt = - (Δv / S)
Δt = - ((Vin - Vcc) / S)
because I expect Δv across the peltier cell should be Vcc + the voltage generated by the seebeck effect because the cell is in series.
then I convert °K to °C
Now that I have the temperature difference between the hot and cold side I can measure with a thermocouple the hot side, subtract the difference I just found and get the temperature of the cold side sticked to the IC.
Are my assumptions correct? will it work?
I know peltier are dangerous with electronics because of the condense but I recently used a dht11 which is a sensor which can read temperature and humidity.
I’ll use it to know how much voltage I can provide to the cell before generating condense using a table like that (I’ll drive it with a transistor) to keep it above the dew point (maybe 1 °C with a 5% tollerance).
I also know peltier are cooling better if the hot side is helped in dissipation, my thermocouple will find place between the peltier cell and a fan
Thank you all!