Controlling a Proportional valve

Other Hardware General Electronics
1

Hello guys,

I'm using an arduino to control a 12V proportional valve (pvq31-6g-40-01 - proportional valve) through a PWM signal.

My circuit looks like this :
Projet Console, Circuit en sortie

Instead of using 24V, I use 12V.

Now my issue is that I can only open the valve but cannot close it.
Even if there's no voltage applied to the gate of the mosfet, there's still air flowing.

In the datasheet, it says that it's a NC valve and that without electrical signal it should go back to its closed state.

Do you guys have any experience with this issue?

Thanks!

2

What did the valve do when you tested it with ONLY the 24 volt supply? Did it open and close properly?

3

Hi thanks for your reply, it did open perfectly. (I did it with 12V)

It's just that it keeps it "open state" even after there's no voltage on the gate of the mosfet

4

BUT! Did it close properly when the 12 volts was removed. That is the key to solving your problem.

5

Do you have a link to the datasheet?

That might be true, but that means it would have to be continuously-powered (whenever not off) which would be "unusual".

Have you confirmed no-voltage across the valve coil?

You might need an H-bridge motor driver to reverse it.

6

If the valve does close when you remove the 12volt connection from the valve, try to connect a resistor 1K between Gate and Gnd.When this approach works try a 10K resistor instead of the 1K.

7

This is your valve data sheet. The valve itself is a current driven device and works on 12 Volts or 24 Volts. The difference being at 12 volt operation the current to operate it is doubled.

The input pressure needs to be within specifications. If the inlet pressure exceeds limits the valve won't close because the tension of the internal spring pushing down for closure id overcome. That's one possible. Anyway, a link to the valve data sheet is now posted.

Ron

8

Thanks, Ron. IF the OP would ever answer questions, I was next going to ask about the valve needing air pressure to operate and you answered the question.
I guess a proportional valve means just that!

9

Hi, @luxofsol
I think it is time for a schematic of your project please.
A hand drawn image will be fine, as long as you label components and name pins.

Have you got the gnd of the controller connected to the gnd of the valve's power supply?

Thanks.. Tom... :grinning: :coffee: :australia: :+1:

10

Yes it did close properly when I removed the 12V power supply, it's really when the power is on that the issue occurs.

11

Yes here's where it says so in the datasheet

Exemple
Exemple1332×707 262 KB

12

Yes I was thinking about the H Bridge btu it wouldn't be overkill for this circuit?
The circuit to drive the valve is the correct one, at first I thought the issue seemed somewhat mechanical.

13

Yes I applied a pull down resistor and it worked fine when driving a distributor or another valve for the matter.

Here's the circuit I officially

Untitled
Untitled778×489 28.3 KB

use :

14

But does it work for the proportional valve?
What is the MOSFET you are using?

Tom.. :grinning: :coffee: :+1: :australia:

15

Thank you for your input and I think you are right.
Maybe the input pressure applied to the valve is the culprit.
It's as if it didn't go back to its initial because the air intake blocks the valve mechanism? Did I understand clearly? If yes, I'll reduce the air pressure to 0.3 Mpa and see what it does.

16

Sorry for the late responses but thank you for your input.

It seems like the issue might be related to the air pressure and less the electronics of the circuit.

I will test the valve with 0.3 Mpa to see the results.

17

Yes there's air flowing inside the valve when I apply voltage on the gate and the mosfet is this one : FCPF600N65S3R0L-F154 and its general specs are N-Channel, 650 V, 6A, 24W.

18

Apparently the "OFF" does not mean there will not be gas leaking through, based on the spec sheet given earlier.

19

Datasheet say max pressure for that valve is 0.12MPa, 1.2 Bar 17 PSI, also that is NOT a logic level MOSFET, needs MIN 5.5V Vgs, what is your Arduino output voltage?

20

If there gas leak than it would mean, it is a faulty valve (if I understood correctly)? Furthermore, the fact that it does not close off when there's no voltage appplied to the gate of the mosfet but turns off when no voltage from the power supply is applied, would exclude the leakage hypothesis?