Im planning on using 2 arduino boards for my project. Should I use 2 voltage regulators for project or use 1 for both?

[kid2077]

For context, my first board would contain a motor circuit with an L298N motor driver while my second contains a controlled heating system that uses 2 relays with PTC heating elements, DHT11 sensor, I2C LCD display, and 1 12V exhaust fan. My input would be a 12V DC power adapter and I'm going to use it to run the motor, the fan, and the 2 heating elements. Since I want to minimize the chances of my boards from overheating, I want to reduce the input voltage for my board to around 7V, so I want to integrate a voltage regulator circuit. Should I include 2 voltage regulator circuits or should just utilize 1 for both boards?

Edit:
I added some rough hand-drawn pictures of my circuits. They are separated right now but I plan on combining them using the same 12V DC power supply. This is for a DIY automatic composting system project.

[UKHeliBob]

Welcome to the forum

Why are you planning on using two boards instead of one and what type of boards are they ?

[paulpaulson]

@kid2077

Since I want to minimize the chances of my boards from overheating,

What you are doing that this is happens?

[kid2077]

They are both arduino UNO

[kid2077]

I heard that 12V could potentially cause the voltage regulator in the board to overheat and I don't want that to happen so I'm reducing the 12V input from the power supply down to 7V

[paulpaulson]

Yes, that's ok for the input to Vin.

But why will you use two Arduinos?

[camsysca]

The only logical reason I can see for you to use two Arduinos is because the two functions being performed are so 'separate' you intend to use off-the-internet codes for both. If that's the case, fine, it does avoid merging the two codes, but it's a bit strange.
The two Arduinos are probably powering their sensors, as well, correct? If so, that's a design limitation that might also force the use of two Arduinos, but it's probably the wrong way to go.