Electronic's Newbie Question about Volts...

[slghtlyoff]

I am planning out a ballast system for a model submarine. I need to control a valve that will release CO2 (or whatever gas) to force water out of the ballast tank.

Additionally, a second valve needs to keep air in the ballast tank and open to allow water into the tank (sinking the sub).

I found a valve that runs on DC, is normally closed and requres 24v.

24v seems like a lot of volts... since this is in a model sub, it needs to come from a small battery(s). Can I link 3 - 9v batteries together to accomplish this?

Thanks for your help! I've been learning a lot over the past couple of days, and have a lot of studying to do, but this part is crucial to the overal diving and survacing of the vehicle.

 

[Resqueline]

Yes, if you have the space you can connect three 9V batteries in series to get 27V.
An alternative is to run from 12 or 18V and build this voltage doubler circuit. It will also save power.
Most relays and solenoids needs almost full voltage to pull in, but once pulled they can make do with less than half the voltage.
The input to the circuit needs to be pulled down (to Gnd) to activate the solenoid.

 

[slghtlyoff]

Thanks!

I appreciate your help! I am glad I found this forum!

 

[(*steve*)]

The most important issue is how much current is required to operate this valve. This will determine the minimum size of batteries required since they need to be able to supply that current.

It will also determine the life of the batteries, but I presume that is a lesser concern.