Limiting Cold Side Temperature on Peltier
Answer:
To do so all that is needed is an automatic variable PWM circuit controlled by the voltage of a thermocouple, a small digital display can be used to set the desired temperature.
Explanation:
The system as a whole must have the capacity to run without overheating, i.e. - the heat output in watts of the item being cooled + the self-generated heat in watts of the Peltier module must be less than the heatsink/fan combination's capacity in watts to dissipate heat or the system will overheat. A Peltier module does not create cold, it cannot. It can only transfer heat. Its semiconductor properties allow it to transfer heat more efficiently by the addition of electrical current, adding its own heat while doing it. The heatsink draws this heat away from the module and transfers it into either a gas(i.e. - the atmosphere via heatsink air current) or liquid(i.e - a water block with circulating cool water) that can absorb the heat. The hot side of the Peltier must be in contact with an energy dissipation device that has a greater dissipating capacity(in watts) than the heat being generated(in watts) by what is being cooled that is in contact with the cold side of the Peltier module + the Resistive heat of the Peltier module itself. if the system does not meet these requirements, the system will fail.