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?