Hello everyone I am trying to evaluate a problem.

I need to control some medium size 1A motors and solenoids. The 12V supply feeds both the loads and the logic through a buck converter. I would like to isolate the two, but I don't know what solution I could use. Perhaps if I fed the logic with an isolated dc converter module derived from the 12V would cost
too much.
Are there different solutions?

 

An isolated dc converter module with careful construction of power commons will work (the extra cost is well worth it as we only have so much hair to pull out). You will also need to isolate the I/O loop paths to reduce conducted noise and shield/route motors and solenoids to reduce radiated noise. Low impedance, current loops for digital signals are preferred instead of high impedance voltage levels.

https://www.astrodynetdi.com/blog/conducted-emi-vs.-radiated-emi-whats-the-difference
Conducted EMI vs. Radiated EMI — What’s the Difference?

https://www.tdk.com/en/tech-mag/noise/02
The Basics—Part 2: Tracing the Invisible—The Roots and Types of Noise

 

Hi @nsaspook thank you for resources.

I attached a draft of the topology I intend to build.
Do you think it is correct?

 

Hi @nsaspook thank you for resources.

I attached a draft of the topology I intend to build.
Do you think it is correct?

Too little information to make an evaluation. Black box models with a single line is not close to sufficient. Re-post something after you flesh it out with detail.

 

@nsaspook
Sorry for my inexperience.
What information is critical for a fair evaluation?

 

@nsaspook
Sorry for my inexperience.
What information is critical for a fair evaluation?

A complete circuit schematic diagram would be a start. A physical working prototype build would be best.

This is AAC, not AAMR (mind reading).

The best you can get without that are general information links and notes about the subject. Attention to detail is the magic of good engineering.