# Solenoid Wiring Question



## jousley (Feb 9, 2012)

hey guys, this is my first pneumatic project. I have all the parts and the 120v solenoid, and double acting cylinder is working fine. My project is basically a door that will open/close via a pneumatic cylinder. I have not been able to be successful in adding a switch to my circuit that when pressed will open the cylinder, then another switch when pressed will close the cylinder. 

I am not new to wiring, but for some reason I can' tfigure this one out. here is what I have tried. 
cut the plug of an electrical cord off. Attached the hot to one side of a switch. attached the other side of the switch to a wire and to the solenoid. Attached the other wire out of the solenoid to the neutral of the plug. when I connect, the solenoid switch has the red led and buzzes, but no activation. 

another question, doesn't a solenoid want just a "pulse" to activate? meaning that if I have a switch such as a light switch, which stays activated when I press it on, won't the solenoid activate and then keep buzzing, because the cylinder will open or close, but electricity is still being applied to it until I turn the light switch off. I hope that makes sense. 

Overall, what type of switch should I be looking at to use in this type of project? a push button? and if so, how to wire it correctly. 

thansk in advance
j>


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## Spooky Dave (May 12, 2011)

Hi Jousley,

I'm no pro at pneumatics, but I can take a stab at this. A solenoid is actually just like a light switch. Meaning, it needs juice in order to stay open. So a push button won't cut it unless you want to hold the button down for the duration you want the cylinder to extend. Which would work. But then, with a double acting cylinder, as soon as you release the button the cylinder will retract. 

Well, that wouldn't be true if the push button (or any other trigger) were interfacing with a prop controller. But that's a whole 'nother ball of wax. For now, just for the purposes of what you're trying to do, here's a basic run down on manual triggering with a switch.

Easiest way in the world is to take one of those cheap brown extension cords, cut off the female end and splice the two wires with your hot/ground wires coming out of the valve. Then plug the male end of the extension cord into a power strip with a switch. Flip the switch on and off.

Yes, you can splice in a switch if you want. In that case, just splice it somewhere in the ground line. But the surge protector/switch combo is by far the quickest and easiest way to get up and running with manual valve control. Then there's a whole world to climb from there.

Good luck! I still remember firing my first pneumatic cylinder. It was an instant addiction that has remained with me ever since. 

Let me know if I've confused you any, or if I can answer any more questions.

Dave


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## niblique71 (Dec 2, 2009)

Good answer SD. However I am curious about the Buzzing in the selenoid. Most selenoids Buzz a little when they are working but yours still doesn't work even when it's Buzzing. Your selenoid piston might be stuck inside the housing. Quite often even new selenoids have a stuck piston. To check this, take the electro magnet off... then take the top of the selenoid off CAREFULLY. If it's Not stuck there's a spring at the opposite end that could propel your piston out of the block. If you've successfully done this... Just press the piston down with Clean fingers and let it return a few times to free it up, then reassemble. If your wiring and air lines are properly connected, Your air cylinder should activate when you turn on your switch.

As for your switch, SD has some great advice. However you can use any switch rated for 120V. Most selenoids don't draw a ton of amps so there are a ton of options available. One option is a regular light switch (In an electical wall box). Turn it on to open the door, Off to close the door. One point to make though. If your door remains open for long periods (Selenoid activated), your selenoid magnet can get rather hot.


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## corey872 (Jan 10, 2010)

Sounds like the set-up should at least function. Are you sure you have an AC solenoid? There are such animals as 120V*DC* solenoids too. One of those hooked to AC line would just buzz and not do much.


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## DarkLore (Jan 25, 2009)

Have you read the thread - Use of Prop Controllers, in the Tech Terror forum? It illustrates the use of relays, switches, circuits, and pneumatic controls.

Read the entire thread, including the use of relays.


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## Darkmaster (May 9, 2009)

My suggestion would be to use a prop controller to activate.
You can also use a self centering toggle switch, which means when you move the switch in one direction, activate the solenoid and let go, the switch shuts off and moves back to the center off position. Now it is ready to go again. Then move the switch in the oposite direction, activate the valve and cylinder in the opposite movement, let go and the switch will return to the center off position.
To make it more simpiliar, use a spring return air cylinder. The cylinder moves out when activated, and returns back on its own.
With a double acting cylinder, you need a triple acting valve. The valve will do 2 directions of movement. A single acting cylinder with spring return, you can use a double acting valve, one direction of movement. 
Hopefully I got it right.


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