# Circuit for controlling 2 pneumatic solenoids

Hello,
I'm currently working on a flight computer project for a rocket and I need to build a circuit to control two pneumatic solenoids that require 12 V and draw 1 A. In order to keep weight down I need to power it either by 9V batteries or maybe something like some 7.4V lithium ion or 11.1V lithium polymer batteries. I'm completely new to circuits and have been trying to search around for a good tutorial, however I'm coming up short since most people have just been using a 12V power source. Any help would be greatly appreciated, thank you!

Solenoids that require 12V, and you don't want to give it 12V. What am I missing here?

Sorry, I guess what I meant was using 2 batteries in series to get above 12V, however I don't know how to build a circuit that regulates the voltage to 12 VDC and controls the solenoids from the digital output pins.

A correct answer can't be given if we don't know if these solenoids will be powered continuous or intermittend, and for how long.
A LiPo has potentially the best weight/power ratio. A 9volt smoke alarm battery probably the worst.
Leo..

A BTS716G chip is great for controlling nominal 12V loads. It understands the inductance of loads like solenoids and handles them very well. It also copes with the usual screwups of prototype work - it handles reverse connections, short circuits, reverse power and more.

Go to OSH Park for a breakout board. It is pretty easy to hand-solder the chip onto the board and there's no other components required.

INTP:
Solenoids that require 12V, and you don't want to give it 12V. What am I missing here?

The 11.1V (3S lithium) will be fine, that's close enough and has good current sourcing ability.

Well, when OP says "require 12v", I naively make the assumption he knows what he's talking about. Otherwise he's wasting everyone's time with false premises.
And he would never ever do that.

"Require 12V" usually means "designed to work from a 12V lead acid battery", in other words will work OK
from 10.5V to 13.8V.