Hi, everybody,

I want to control two Peltier elements (up to 15V, max 6A each) with an Arduino. Right now, I am able to control them using PWM and a MOSFET (IRLZ44) to modulate an incoming constant voltage signal.

By varying the amplitude of the PWM signal at the Peltier, I recognized, that I am able to achieve lower temperatures with a 9V signal, than with a 12V signal. Unfortunately, the voltage supply I intent to use in the final setup is 12V constant with up to 33.5A (used for 2 Peltier elements, a fan and an Arduino)

I guess, one possible solution would be to smooth the PWM signal after the MOSFET using a low pass filter (?) to obtain and vary a constant applied voltage at the Peltier by changing the PWM value. Is that possible? How would that look like? What components and component sizes would I need to implement this?

Or do you know other possibilities to solve the problem?

Attached you can find my findings of the minimum temperature by varying the input voltage and PWM and a sketch of my setup.

Thanks for any help!

 

Ideally a proper circuit diagram is best to understand what is going on.