6 solenoid valves (12V) to be powered by one Arduino using MOSFETs, possible?

Other Hardware General Electronics
1

Hi,

I want to controll six solenoid valves with my Arduino (not simultaniously, they shall open the water flow to six different plants and it doesn't need to happen at the same time). I tried with just one valve and it worked fine, by following this guide: Controlling A Solenoid Valve With Arduino - BC Robotics

Is it possible to power six valves with the same concept, by just adding one MOSFET per valve, or do I need an external power supply? In that case, should I build a parallel circuit with six branches and a 12V power supply?

I'm using these valves: http://www.electrokit.com/en/plastic-water-solenoid-valve-1-2-12v.51108
And a P-channel MOSFET (30V/60A) as well as the transistor and the resistor from the guide linked above.

Thanks in advance!

/Erik

2

What is powering the valve now then? You don't get 12V from USB so what is your supply?

Why do you have a p-mosfet and the tip20??? You can put the p-mosfet away and to make it more efficient swap the tip120 for a logic level n-mosfet.

3

septillion:
What is powering the valve now then? You don't get 12V from USB so what is your supply?

Why do you have a p-mosfet and the tip20??? You can put the p-mosfet away and to make it more efficient swap the tip120 for a logic level n-mosfet.

The solenoid valve works between 6-12V according to the specification, I might just have been lucky that it worked even with 5V. Before I saw this guide I used an external 12V power supply to power the valve. While testing I'm using the USB to power the Arduino, but when in "work mode" it shall be powered by from a regular 230V socket.

I used a P-mosfet because I found one in the workshop, but I'm about to order a bunch of them so I can choose N instead.

Like you probably have figured out I'm pretty novice in this area, especially regarding how to power all the components properly.

4

If the spec say 6V to 12V then get a 6V to 12V supply :wink: At 5V it might work now but it also might not work. That's where specs are for.

And just use the schematic you found (aka, don't forget the diode) and you may swap the TIP120 for a n-mosfet (with a lower or no gate resistor) because they are more efficient. But it the TIP120 doesn't get hot it's probably fine as well. Little bit less efficient but the tip120 is probably cheaper. But check the solenoid specs to see the current draw of it.

5

Thank you for your answer!

So according to my insane math and electronics skills, this power supply should be enough for powering 6 solenoid valves? http://www.electrokit.com/en/power-supply-515v-3000ma-stab-switched.48610

At 12V, the maximum current is 3000mA and one valve draws 320mA at 12V (which means that 6 parallel valves draw 6x320=1920mA at 12V). Makes this logic any sense?

6

If 12V is the max of the solenoid I might not choose 12V... But apart from that, it looks okay. Can't see the specs so I'll have to believe you about the 320mA.

7

septillion:
If 12V is the max of the solenoid I might not choose 12V... But apart from that, it looks okay. Can't see the specs so I'll have to believe you about the 320mA.

Here is the specs for the valve: http://www.electrokit.com/en/plastic-water-solenoid-valve-1-2-12v.51108

Normal working voltage is 12V(320mA), but works down to 6V(160mA).

Btw: Fading LED lights is also part of my project, so I will definitively look up the library in your signature :smiley:

8

Than I'll see no problem in a 3A 12V supply :slight_smile:

Nice! Probably push an update this evening which makes it behave a bit nicer it you try to update it very very often during fading. (Not a problem during normal fading.)