Hello - cool forum. I'm trying to control a solenoid valve with my Arduino.
Here are the specs on the valve:
Voltage Range: 0-10 vdc
Power Consumption: 1.9 watts, 2.3 watts max
Response Time: 3 to 5 ms
specs: http://www.kpiwebsite.com/docs/MPVspec.pdf
I want to control this valve with a Potentiometer (I have two linear pots ... one is a 6k and the other is 10k.. not sure if I can use either of them). So basically I would like to open and close this valve by turning the pot and would like it to be smooth.
I would like to use a 9v to power the valve....
On another forum I was told that using PWM is what I need... but I still don't really get it.
Does anyone know of a tutorial for operating a similar valve via potentiometer? Is there some sort of shield I could get to make it really easy?
I'm super green to circuitry and the Arduino... forgive me...
The chart on that page you linked indicates, and this page on the site confirms, that it's current that controls the solenoid.
A potentiometer would provide you with a voltage, but somehow you'll need to get that converted to a current. I have no idea how to do that but I daresay some of the gurus here will be able to advise.
JimboZA:
The chart on that page you linked indicates, and this page on the site confirms, that it's current that controls the solenoid.
A potentiometer would provide you with a voltage, but somehow you'll need to get that converted to a current. I have no idea how to do that but I daresay some of the gurus here will be able to advise.
Some hardware such as the attached will do the job. The capacitor, 100K resistor and 9.1K resistor smooth the PWM output and divide it down to be in the range 0 to 0.44V, and the op amp, transistor and 2.2 ohm resistor convert that to a current in the range 0 to 200mA.
Then all you need to do is read the value from the pot, scale it to the range 0 to 256, and analogWrite the value to the chosen PWM output pin.
Those valves you listed are sold with certain optional voltage ranges, are you sure you have to control the current rather then just control a voltage from 0 to 10vdc that will span it's operating range? It seems to me they show a graph of the current the valve will draw for the voltage applied to it.
Lefty if you look at the pic on the other page on the site, to which I linked above, it's more explicit that it needs to be supplied with certain current...
JimboZA:
Lefty if you look at the pic on the other page on the site, to which I linked above, it's more explicit that it needs to be supplied with certain current...
I guess your right as they have a driver board available to convert the control voltage input to the current drive for the valve:
JimboZA:
Lefty if you look at the pic on the other page on the site, to which I linked above, it's more explicit that it needs to be supplied with certain current...
I guess your right as they have a driver board available to convert the control voltage input to the current drive for the valve:
Ok, so maybe I should just get the driver board since i'm so new at this.
Will that be possible and easy to connect to the Arduino?
Again, forgive my lack of knowledge on these things... I'm doing a little project with my sons and we just need this valve to work with a potentiometer asap.
Am I missing something? If the potentiometer is aranged like a rheostat and put in series directly with the solenoid, wouldn't that just change the current flowing through the solenoid? Ohms law says at 90 ohms, you get 100mA or max air flow, and at 225 ohms you would get 40mA for minimum airflow. Of course, you need to subtract whatever resistance is in the coil inside the solenoid.
A 500 ohm potentiometer with a 91 ohm resistor also in series would keep the max current in the safe range, though I wouldn't be surprised if the coil itself is about 90ohms which is why it is the limit. And if it IS 90ohms, then leave out the 91 ohm resistor and only use the 500 ohm rheostat.
(A rheostat is just a potentiometer with the center tied to one of the other legs so it is just a variable resistor.)
You could put a 510 ohm resistor in parallel with the rheostat and you would get a range of 91 to 250 ohms. Right around what you need.
Current will be .9W at 100mA, so use a 1/2W resistor and rheostat. Or if only using the rheostat, use a 1W.
If you ONLY want to use a potentiometer to control the valve, I would think that is all you need to do. No need to convert a control voltage to current here. That would be if you were trying to control it with an Arduino or other microcontroller.
bandsons:
Hello - cool forum. I'm trying to control a solenoid valve with my Arduino.
Here are the specs on the valve:
Voltage Range: 0-10 vdc
Power Consumption: 1.9 watts, 2.3 watts max
Response Time: 3 to 5 ms
specs: http://www.kpiwebsite.com/docs/MPVspec.pdf
I want to control this valve with a Potentiometer (I have two linear pots ... one is a 6k and the other is 10k.. not sure if I can use either of them). So basically I would like to open and close this valve by turning the pot and would like it to be smooth.
I would like to use a 9v to power the valve....
On another forum I was told that using PWM is what I need... but I still don't really get it.
Does anyone know of a tutorial for operating a similar valve via potentiometer? Is there some sort of shield I could get to make it really easy?
I'm super green to circuitry and the Arduino... forgive me...
I'd like to apologize for bumping this thread, but how much does that cute small proportional valve cost? The ones in India are very heavy compared to that, and I'm thinking of importing some.
