Thread: Pneumatics noobie needs help with 12VDC Choice

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Hey everyone, this is my first go around at doing pneumatics and I might be a bit over my head, but I'm getting hooked.

I bought 2 pneumatic cylinders and 2 solenoids and a Nerve Center controller from Monster Guts. I'm going to create a stretching rack that will extend the body with the 12" stroke cylinder, then another 3" stroke cylinder will make the body shake as it's being stretched.

I have a few questions on the hook up of the mechanical/electrical pieces of the solenoid.

I have 2 solenoids, each rated as 12VDC, 250ma, 3W.


In an effort to clean up wiring, I would like to accomplish this by only using 1 Wallwart to power both solenoids and a set of blinking eyes that will be triggered as well when the smaller 3" stroke cylinder is triggered. I don't want to use the Nerve Center's 12VDC hookup because I don't want to ruin it.

1. Can it be done with either of these two wallwarts?
2. Should I just stick to using a wallwart for each solenoid so I don't burn it out?
3. Is there a recommended wallwart I should be using to accomplish everything here?

I bought a bunch of different resistors for this project, so I should have those handy. According to the calculators online, I need to use a 390 or 470 ohm resistor. I already opened the package of LED lights but here are the specs:
http://www.radioshack.com/product/in...ductId=2062563
10mm Red LED
Peak emission wavelength: 660 nm
Light output: 5000 mcd @ 20mA
Forward voltage: 1.85V

Wallwart #1


Wallwart #2


LED Package

Looks like each solenoid needs 250ma so running simultaneously you're looking @ 500ma which is the rating for the first WW. Then you want to drive some LED's which need a little bit more current. I would go with the 1000ma wart. You need to be able to supply enough current for everything you want to power up.

cool. just making sure I'm not going to blow my solenoids by running too much current

The rating on the power supplies are the maximum current that they can supply. You always want to choose power supplies that are rated at a higher current than whatever your devices will pull. And make sure you wire them in parallel, not series!

ok now i'm confused. So can i not just connect them both like this image below to the same wallwart?

That looks fine , use the 1000 ma power supply. If you get a power supply that is rated at a higher ma or amp, that is alright. The amperage ratings are how much apmerage that can be drawn from the power supply before you start having problems. Hope this helps

awesome. thanks for all the quick replies everyone. Once it's built and functional, I'll be posting the final product with video.

Test your power supply under no load with a multimeter and see if it puts out 12v. It needs to be regulated (i.e. puts out the correct power no matter how little is attached to it) otherwise you might go overvoltage. This is less of an issue with mechanical parts but it'll probably fry your LEDs. If not, here's a clearance item:

http://www.parts-express.com/pe/show...number=129-077