I bought 2 solenoid valves. I'm looking to turn them on/off using my relay. However, I'm not sure what the best way to power them would be. Do I plug them directly into the wall (after attaching a wall connector to the wires)?

I know wall outlets are 120V. So does that mean I need to get a converter?

EDIT: http://www.amazon.com/gp/product/B00827FP26 http://www.amazon.com/gp/product/B00004S1V2

Those are the solenoid valves I'm using.

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    \$\begingroup\$ Rule for projects, do not plug anything directly into the wall. At some point you'll know when you can break the rule. \$\endgroup\$ – Samuel Nov 20 '13 at 2:32
  • \$\begingroup\$ Hard to answer your question without knowing more about the solenoid valves. Post a link to the datasheet, please. \$\endgroup\$ – Nick Alexeev Nov 20 '13 at 3:31

That is listed as 12V DC solenoid so you definitely don't want to try plugging into AC mains directly as fire and/or death may follow. Unfortunately it doesn't seem to mention the coil current, if you have a multimeter you could set it to the 10A range and connect it to a car battery with the meter in series to measure.

But otherwise I have a solenoid of fairly similar size (although a gas one) and I just measured it as around 1.5A. I'd hazard a guess those would be under 2.5A so I think a 12V DC power supply with a current rating of 5A would be sufficient for the pair of them.

As you've already sorted out controlling a 5V relay using the Arduino it sounds like a power supply is all you need. They are available from most electronics stores, e-bay etc in many styles but here's an example on Amazon.


You're trying to control the solenoid from an Arduino? Or from the wall outlet? Is this 12V DC or 120VAC. Do you have a datasheet?

If you want to control a 12V solenoid from the Arduino, you'll need to get a GPIO to switch a 12V supply for you. You can do this thru a transistor (smaller arduino IO voltage controlling the base of a MOSFET that's switching a 12V source).

Do you have a spec on the solenoid? Also, have a look here at the switching circuit. Plenty of information out there re: solenoid switching.


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    \$\begingroup\$ Incidentally, the flywheel diode is important. A must have. Also have a look at this post. It's designed around arduino: bildr.org/2012/03/rfp30n06le-arduino \$\endgroup\$ – DoubleE Nov 20 '13 at 1:45
  • \$\begingroup\$ Sorry, I should have been more clear. I want to use a 5v relay controlled by an arduino to turn on/off the solenoid. I just need a way to supply 12v DC to the solenoid. I'll post the links to the products in my original question. thanks. \$\endgroup\$ – Matthew Berman Nov 20 '13 at 6:19
  • \$\begingroup\$ EDIT: If you're going to use a relay, scrap the bit below about the MOSFET and use that. The rest (below) still stands: <snip> Ok...well that's easy. :) You need the MOSFET circuit to switch the thing using the GPIO on the Arduino. So that part still stands. Now you need a 12V supply. If you have a 12V wall wart you can use that. Have you checked out this post yet? Discussed the topic nicely. electronics.stackexchange.com/questions/78068/… <snip> \$\endgroup\$ – DoubleE Nov 20 '13 at 8:16
  • \$\begingroup\$ ...And again, the diode is not optional. Read up on Flyback diodes and inductive loads. \$\endgroup\$ – DoubleE Nov 20 '13 at 8:31

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