# Flood Light Sensor with Solenoid



## Nathan2485 (Oct 27, 2012)

I'm brand new with this and was hoping there is a quick or easy solution.

I am currently using this Solenoid http://www.princessauto.com/pal/pro...DC-Solenoid-Activated-Pneumatic-Control-Valve

I can successfuly manually make the cylinder go up and down so I know my air flow is correct.

And I have it all hooked up to a double acting cylinder - working one way - with the flood light sensor - so I am able to trigger the motion sensor to make the cylinder go up. I am clueless how to get power to the other solenoid to make the cylinder go back down after the motion sensor has reset itself.

(Hindsight, I should have just bought a single acting cylinder with one solenoid but I was a little ahead of myself.)

Floodlight motion sensor - I have a 12VDC adapter pluged into one of the light terminals (using a screwin plug adapter) to power the one side of the solenoid.

Thanks in advance! 
Nathan

Any help/advice would be great!


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## Wildcat (Nov 3, 2007)

You could use an SPDT Relay (Single Pole Double Throw)

















Wire the closing action to the N/C and the open action to the N/O

What this will do is when the prop is not being triggered, the solenoid will be pushing air to the closing action of the cylinder. Once the prop is active it will shut off the N/C pin and activate the N/O pin which will activate the prop.


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## Nathan2485 (Oct 27, 2012)

Thanks Wildcat - I figured it would be a relay of some type! So once the prop has been activated, and the motion sensor has reset itself - the relay will trigger the solenoid to close the cylinder going back to rest?


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## Nathan2485 (Oct 27, 2012)

Would this relay work @ princess auto?

http://www.princessauto.com/pal/product/8402042/Switches-%26-Indicators/40A-12V-DC-Change-Over-Relay

And could I just crimp the wires with this socket attachment?


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## Wildcat (Nov 3, 2007)

That relay will work. Yes you can use crimp connectors but I prefer to solder and use heat shrink on connections to make them water tight.


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## Nathan2485 (Oct 27, 2012)

Thanks again - hopefully if all goes well I will post prop today


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## niblique71 (Dec 2, 2009)

With the selenoids that I am familiar with, When the selenoid is deactivated (No power) the air flow flows in direction "A" to the cylinder to make it go one way (Lets say "down" or "closed" for example). Then when you apply power (12V wall wart) the air flow switches to flow "B" and goes the other way (Cylinder goes Up). Unplugging, or deactivating the selenoind again returns the airflow to normal to make the cylinder go back down. 

Help me understand why a "Relay" would be needed if your just activating a 12V Wal wart (Power source) on/off with the 120V motion detector. In theory, with the wal wart unplugged, the airflow would force the cylinder down, and when you plug in the wall wart in, the cylinder would go up. Unplugging it again would force it back down etc, etc. I might be missing something, and am very curious about the solution.

The motion detector should do this without a relay...I would think.??


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## Otaku (Dec 3, 2004)

That's been my experience with using 4-way solenoids. It works provided you have the cylinder retract port connected to the solenoid exhaust port. I'd advise opening any closed-off ports and finding which one goes open to atmosphere when the solenoid is off.


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## Nathan2485 (Oct 27, 2012)

Ok..Do you have a diagram to show how to hook this up....the relay still hasn't been successful...so I am willing to try anything at this point...nothing like last minute!


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## Nathan2485 (Oct 27, 2012)

Well thanks to everyone who helped out - I ended just picking up a 3 port 2 way solenoid and had no problems with that - after all it was just the plumbing. Later tonight I will post a quick tutorial for anyone brand new to this like me and up-to-date prices for a simple pop up pneumatic device...now onto the build.


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