hello, I want to connect an rpi 3 b+ to 2 12v solenoid locks, a camera and a speaker module and microphone module. I cant figure out what i need transistor wise though. will a 12v 4 channel relay not be enough to power both locks? im beginning to think no and should have gotten 24v. mosfet? im really lost as to when you use one vs the other and if you can use both. aux power jacks: do i connect to the relay of i have one and if i dont the mosfet?

 

Not sure of your circuit, but there is the Omrom MY4ZN 4 pole style relay with 4 contacts.
You could also drive with Mosfets, are these switched simultaneously?
Max.

 

the 2 12v sols are simultaneous. would i need two mosfets then? each sol will be powered by its own ac wall adapter and i think i need to get a barrel jack that i can hook to either the mosfet or the relay? im newer with electrical engineering and i can confirm its not as easy as some think. haha

 

You should be able to power with one Mosfet, don't forget the reverse diodes across the solenoids.
Also two could be used from the same drive signal.
It helps to post a circuit and component details for definitive answers.
Max.

 

so im piecing together a midified version of https://www.raspberrypi.org/magpi/windows-iot-facial-recognition/ but with 2 locks, a button to unlock from inside, and the rest is the same. ill be able to post specifics on the parts i do have when i get back to my house later