Driving multiple solenoid valves with Arduino Mega

Other Hardware General Electronics
1

Hello all, this is my first post and I am pretty novice when it comes to arduino.

I am making a mechanism to re-direct inline flows that requires the use of 4 2/2 NC Solenoid Valves. These are the valves (12V DC Solenoid Valve. They each need a current of 540mA. I tried setting it up with just one solenoid and can not get it to actuate and was wondering if anyone had advice on perhaps a piece I can purchase that can easily handle my application, or what I am doing wrong. I followed a circuito.io diagram and this is what I have set up. (The reason I did not go the relay route was because I need fairly fast control and the solenoids will be actuating quite frequently which I read mosfets/transistors would be better for. Please do correct me if I am wrong. The solenoids will be actuating on/off every <2 seconds or so.)

What I currently have set up is as follows and an image of the circuito diagram is attached.

Diagram
Diagram854×625 124 KB

I have an external 12V 3A rechargeable battery from TalentCell that is hooked up to the breadboard for power (I heard supplying 12V 2A direct to the arduino could cause overheating issues etc.). I have a N-Channel Mosfet IRF510 that I had laying around that I tried using but can and will definitely purchase something else if it is necessary. Using 10k ohm pull-down resistors, and 1N4007 diode rectifiers. Additionally I tested to make sure my mosfet opens/closes.

Any advice is greatly appreciated! Sorry for not knowing too much!
As an optional question I just wanted to make sure I had a good understanding of the circuit, is the diode used to prevent problems with flyback current from the solenoid or does it have another purporse.

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What is the Vgs for full saturation?

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Use a Logic Level MOSFET.

FYI

1 Like
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Also, power the solenoids with their own power supply.

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Thanks for all the information Larry,

I was planning on buying a pack of FQP30N06L's which I believe should work for this. Thank you for the figure, it is very helpful! The rated Vgs limit on the IRF510 datasheet was +- 20V with a Vds limit of 100V (I will be going with the Logic Level Mosfet you mentioned though).

I was wondering if you could clarify the power supply situation for the solenoids. My current plan was to have them all powered off of one 12V 3A supply externally. (Each solenoid would get its own mosfet etc. but would be driven from the same source.) My arduino and other sensors will be powered off of a different supply. Will this suffice or did you mean that each solenoid should have a different power source?

Thanks for the information!

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Solenoids can have the same power supply.

What is the resistance of the solenoids ?

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The resistance was not listed on any source I could find but the measured resistance across the leads was 21.4ohms.

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That’s what’s needed.

Power supply needs to be:
12V / 21.4R = 560 mA for each solenoid then add 1A just to make sure.

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Thanks for the help Larry!

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You should not use a breadboard for this project. Breadboards are intended for low power logic circuitry, and the tracks will burn when used for motors and solenoids. You will need to learn to solder connections.

I recommend these half size PCB protoboards: Adafruit Perma-Proto Half-sized Breadboard PCB - Single : ID 1609 : Adafruit Industries, Unique & fun DIY electronics and kits

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Thanks for the information Jremington! I will look into them! Question, is it not fine to prototype on the breadboard to test if it works (for a few cycles) then move to a move to a perf board after? Also, any advice on what gauge I should be using to drive these currents? Is 22awg too small or good enough?

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You will probably damage the breadboard, but they are cheap.

Look up wire current carrying capacity in the AWG table.

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And always be conservative. It's not unusual to break a wire strand or two in installation, more with wire flex down the road. So as an example, using a wire that will "just barely" carry your design circuit is "design to fail", using a wire that will carry 1.5x your design load is "design to survive", and using a wire that will carry twice your design load is "design for success". It's your choice.
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I think one of my confusions with the 22 awg wire is the rated capacity I have found differing figures from sources (Like 0.9A all the way up to like 7A or so). I will just go the safe route and plan with the lowest number. Thanks for all the advice ya’ll!

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Some of those sources are very conservative, the other end are dreaming. Maybe, in free air, if the stars align just right and the manufacturer was giving away his excess copper, a 22 ga wire would be adequate for 7A. But...
Conditions make a huge difference, as does the wire composition. Pure copper in free air is one thing, but there are Al-Cu alloys out there as well. Then, , it changes when you either insulate the wire, put the insulated wire in a cable, then run that in a restricted space, etc. etc. So yeah, you can get different numbers, but many times they're explainable. Yootubers and others doing show-and-tell sometimes gloss this over, or downright don't know.
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Really? :astonished:

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Yes, the benefit of copper and aluminum wires!

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Not sure if you're joking. Alloys tend to have different properties than a simple combination or averaging of properties would yield.

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The benefit of Al/Cu wires is improved connectivity to standard copper wiring along with the lower cost of Al.

Pure Al wires were prone to oxidation and creep. Problems were at the connections. Higher risk of house fires.

I don't think he was talking about 2000 series Al alloys (copper)

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I would think, cost is the major issue with the escalating cost of copper.