Controlling water pumps and solenoid valves

Using Arduino General Electronics
1

Hei,

I am currently working on a project involving a 230v 3.3A centrifugal pump, 12v 3.3A submersible pump and six 12v 1.4A solenoid valves.

To get around playing to much with 230v, I am thinking using the PowerSwitch Tail 240 kit for the 230v pump. To my understanding this would make me able to switch on/off the pump with just a signal from the arduino.

What would be the easiest/best way to control the valves and the 12v pump? I know there are different kinds of relays, transistors and MOSFET out there, so I was hoping that someone here could point me in the right direction :slight_smile: I have searched and found some information about controlling 12v devices, but nothing that can handle the currents that I have to be able to.

Best regards,
Marius

2

Relays are easiest - automotive relays are cheap, easy to get and handle lots of current at 12v.

However most relays can't be driven directly from the Arduino. You will need a transistor, usually a MOSFET, to do this.

But one of the reasons why lots of us love the Arduino is you can buy relay boards ready-made. Radio Shack has them. (If they haven't shut down in your area.) Ebay has zillions of very cheap ones. Stack one of those on your Arduino and the problem is solved.

3

MOSFET to switch pump - any logic level n-channel MOSFET with 0.02 ohms on resistance
or lower. You also need a free-wheel diode across the motor to prevent inductive spikes, rated
at 3A peak.

One little question though 3.3A 12V motor - is that the load current, stall current or no-load
current?

For solenoid valves same MOSFETs, same free-wheel diodes...

4

A big thanks to both of you!

Then I will look into using relays and MOSFETs to control the valves and the 12v pump.

MorganS: Relay boards could be used, they are dirt cheap on eBay. Around 10$ for an 8-channel relay board could solve the whole problem. The ones I have had a look at seems to be active low relays. I will have to do some research about how this affect my project.

MarkT: I had another look in the data sheet. The pump draws 3.3A at open flow, in other words when there are no restrictions at the outlet side of the pump. The data sheet also states that the pump comes with a 6A fuse.

Edit: Do you have any thoughts about the PowerSwitch Tail? Seems to me to be an easy and relatively cheap solution for controlling the 230v pump.

5

Mariuslk:
Hei,

I am currently working on a project involving a 230v 3.3A centrifugal pump, 12v 3.3A submersible pump and six 12v 1.4A solenoid valves.

To get around playing to much with 230v, I am thinking using the PowerSwitch Tail 240 kit for the 230v pump. To my understanding this would make me able to switch on/off the pump with just a signal from the arduino.

What would be the easiest/best way to control the valves and the 12v pump? I know there are different kinds of relays, transistors and MOSFET out there, so I was hoping that someone here could point me in the right direction :slight_smile: I have searched and found some information about controlling 12v devices, but nothing that can handle the currents that I have to be able to.

Best regards,
Marius

you can use contactor to switch the 230v pump from a arduino relay

6

Powerswitch tail is a very good idea if you only need to switch one mains outlet. It keeps all the dangerous stuff safe.

7

MorganS:
Powerswitch tail is a very good idea if you only need to switch one mains outlet.

According to adafruit, it's been disco'd, but then this is an old thread.

(Mind you, it's not clear if adafruit has just stopped selling it, or if it's no longer available to them.)

8

Oops. I didn't see the date.

9

Why not a SSR for the 230V pump. Basically any random firing SSR with 3-32VDC control voltage can be used directly from any arduino I/O-pin.

I agree with all who suggest MOSFET for the 12V DC loads. Although I prefer to use proper MOSFET driver IC's for my MOSFETs.

10