# Help regarding a 24V DC pneumatic solenoid valve.



## Anurag_narayan

Hi all
I am working on a project in which an Arduino is used to control a 24V DC pneumatic solenoid valve. The application requires high-speed switching. Accordingly, I have used the 'delayMicroseconds()' function in my program. The solenoid is switching, but the problem is that the air output isn't. I tried increasing the air pressure but that did not work. Please do suggest any alternative, if possible.

Any help is very much appreciated. 

Thanks!


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## Anurag_narayan

Sorry 
I forgot to give the reference.
(http://www.instructables.com/id/Controlling-solenoids-with-arduino/)


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## David_AVD

Is the solenoid even capable of operating correctly (mechanically) with such a short pulse ?


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## Anurag_narayan

I think , yes! I could hear the sound at the high frequency but it is very feeble. I could also hear the change in the sound when I changed the delay.


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## bfjou812

What type of solenoid are you using? What is the output of your 24 volt DC power supply in terms of amps. Also is the solenoid good ,wired correctly, have a minimum air pressure to work? If you could post some pictures and more information it would be a lot easier to help.


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## corey872

How many 'microseconds' are we talking here? You've got two items...an electromechanical solenoid and air... which are both going to have some hysteresis. ie - when your control signal is 'on' it's going to take the solenoid some time to energize and open, then once it opens, it will take some small amount of time for air to start flowing. It will take even more time to build some appreciable pressure and operate what ever is attached to the other end.

Microsecond switching is usually the realm of transistors, not magnetic solenoids and air.


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## Anurag_narayan

Oh!
The solenoid is switching but the air isn't. So any way to make it work?


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## corey872

Still working with a very vague picture here, but if you're really switching in the microsecond range, I see two main possibilities:

1) With air, such fast switching might simply be equivalent to a lower pressure / lower flow static source of air. ie - if you have a 60psi air source and are trying to switch it even 10x per second - or once per 100,000 microseconds - after even a couple feet of tubing, that air might simply be equivalent to a 5-10psi source which is always on.

2) If you really need to switch that fast, it might be the domain of an electromechanical actuator. You'd need to cut the air out all together and just let something like a solenoid or linear actuator do the work.


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## DarkOne

My cylinders with a two inch stroke I could MAYBE get to go out, back in, and out again in one second, but not any faster than that. That's at about 40-60PSI. Those are 1.06 bore. My 5" stroke, 1.5" bore is quite a bit slower at the same pressure. The larger the bore and/or stroke, the slower the cylinder can respond. To get faster response, you'd need to be using a very small cylinder like the ones on Autococker paintball guns. I think it would have to be moving something pretty small or be very well balanced with bearing to make the movement as frictionless as possible.

How many cycles per second are you trying to get, and what are you moving?
Maybe someone can help if we have more information.

The previous post is right, maybe pneumatic isn't the way to go?


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## MadCityHaunt

Hi Anurag,

These might seem like some basic steps but in tech support we always start there and work our way up.

If you are using a 4-way solenoid can you confirm your air line IN is going to "P" and not "A" or "B" (see attached image.)










Also, can you simply connect your two solenoid wires (red and black) to a 24v power supply forgoing the Arduino board and confirm it switches and lets air pass through?

If the solenoid is working (and passing air) when it's not connected to the Arduino board, reattach it and try doing a longer timing in your code like 5,000/ms or 10,000/ms to rule out the switching happening too quickly.

Also does the Arduino board support 24v output? I am new to Arduino and don't know all the limits of the boards. Maybe double check that the board is capable of putting out enough power to run the solenoid without the use of a relay. If the board is not putting out enough power, could you add a relay to the circuit to do so? Can you use a different flying lead for the solenoid to change the voltage requirement if needed?

Another alternative (depending on what you are trying to do) might be the use of an electric door actuator.

Good luck, post your results here as I'm sure other members will be interested to find out what you determine!


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## bfjou812

Did you ever figure this out?


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## David_AVD

Looks like he joined and asked the question and hasn't been back since.

I doubt that he really knew what he was doing.

The extremely low on times he was quoting were likely the issue.


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## Zoolando

What a predicament


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## CelleCasey

I want to know that how many 'microseconds' are we talking here? You've got two items,an electromechanical solenoid and air, which are both going to have some hysteresis.When your control signal is 'on' it's going to take the solenoid some time to energize and open, then once it opens, it will take some small amount of time for air to start flowing. It will take even more time to build some appreciable pressure and operate what ever is attached to the other end.


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## corey872

CelleCasey said:


> I want to know that how many 'microseconds' are we talking here? ...


Yeah, we tried that back around thanksgiving...

http://www.hauntforum.com/showpost.php?p=845217&postcount=6

Anurag was a bit scant on details back then, and hasn't been back to answer any additional questions in the ~5 months since. So I'd probably give up on this zombie thread. ...and the associated spam bots.


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## David_AVD

I know this is an old (dead) thread, but I read something interesting in the data sheet for some air solenoids today.

It specifies the "Shortest excitation time" as "0.05 second" which is 50 milliseconds.

That's possibly a useful thing to know for anyone programming a prop controller and trying to do short bursts.


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