I originally graduated with an EE degree, but have since been removed from these kind of projects. I am trying to get back into it, and start up my new hobby. I have decided to do a project that will control 6 solenoid valves (2 at a time maximum). I have done some reading on what my circuitry should look like, and have copied what seems to be the inductive load circuit norm for my circuit.
Attached you will find a scan of my first pass at the circuit. I was hoping to gain some insight from others on if it looks like a decent design and if there are any other things that I should be mindful of.
Also, I am not sure about the resistor value and the NMOS model that I have chosen for the circuits. From what I can tell, a simple NPN BJT will not work for me, so I will need a MOSFET or a Darlington. I went with the MOSFET and basically just went with something that looked decent from TIs website. It is hard to really choose a resistor without knowing what the resistance is looking into the gate. I remember doing equations for that in college, but can not recall the formula to use to calculate the resistance. Any thoughts?