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Powering Raspberry Pi with 12V power adapter a good idea?

Posted: Wed Jul 01, 2020 1:58 am
by CliffRT
Hey guys,

I know there are plenty of posts out there regarding 12V power supply to a Raspberry Pi.
I'm not very familiar with circuits and power as a whole.
So I've got a Raspberry Pi for awhile now, I've done simple projects that mostly uses flow sensors and servo motors and components that uses less than 5V.

This time however, I'm looking to use a 12V DC solenoid valve on my Raspberry Pi.
I've seen plenty of posts on how to make a solenoid valve work, but they only have a solenoid valve on it.

My question is, if I were to work a solenoid valve with other components with it such as servo motors, flow sensors and load sensors, would all of it collectively draw too much amps that it might fry the Raspberry Pi? Would a 12V power adapter be capable enough to make all the other components work?


Cliff.

Re: Powering Raspberry Pi with 12V power adapter a good idea?

Posted: Wed Jul 01, 2020 5:58 am
by RGJ-PI
If you mean putting 12V into the PI power USB then really not a good idea at all. It will damage the main power supply chip pretty much instantly.
If you have 12V devices you need to switch then you could either use a 12V supply with a 5V step down circuit for Pi power but as you say you are not comfortable with circuits and power you might be better off just using a RPi PSU for the board and buying a relay module to switch the solenoid with a sperate 12V PSU.

Re: Powering Raspberry Pi with 12V power adapter a good idea?

Posted: Wed Jul 01, 2020 9:06 am
by LTolledo
12v --------------------------------------------------------------->-(Transistor or MOSFET) -----------> solenoid valve
12v ------buck converter --------(5.1v) ------ RPi USB-C (or RPi microUSB)
RPi GPIO (3.3v)-----resistor----transistor or mosfet (above)

Re: Powering Raspberry Pi with 12V power adapter a good idea?

Posted: Thu Jul 02, 2020 8:02 am
by CliffRT
Many thanks to you both! I will look and read further into it.
I'll take the safest route about it.