Need advice: controlling 4 independent solenoid values with fast switching freq

I need to control 4 independent 12v solenoid valves via a microcontroller. I need to be able to adjust the frequency of the fluid passing through the valve such that each fluid is passing through at a rate different from the other valves. I need the controller to actuate the solenoid values as fast as physically possible.

Can I achieve this with a TinkerKit Sensor Shield, 4 TinkerKit Mosfet Modules or TinkerKit Relay Modules, and the Arduino DuemilaNove?

Would you recommend a better way?

And an external 12v power supply

I need to be able to adjust the frequency of the fluid passing through the valve such that each fluid is passing through at a rate different from the other valves.

That is not clear to me what you are trying to say there. However if the restriction is in how fast you can pull in or release a solenoid, I would suspect the limit would be in the mass and induction of the selected solenoid not in the ablity of an arduino to turn a signal on or off?

Lefty

See http://www.instructables.com/id/Controlling-solenoids-with-arduino/ for one example.

You could also achieve this with the Mosfet Module which is essentially just a board containing the parts described in the tutorial above.

Any Arduino is fast enough to handle this type of activity. As Lefty mentions an Arduino is capable of switching a transistor or mosfet at a rate much faster than the solenoid can move; you'll be capable of tuning it to hold the solenoid between fully closed and fully open.

retrolefty: That is not clear to me what you are trying to say there. However if the restriction is in how fast you can pull in or release a solenoid, I would suspect the limit would be in the mass and induction of the selected solenoid not in the ablity of an arduino to turn a signal on or off?

Lefty

Hi. I didn't really expect controlling 4 independent solenoid valves to be a problem for the device but I just wanted to make sure. The some of the valve I have looked at claimed response times around 20 ms. I realize this is slow in terms of computers, but I am not extremely familiar with microcontroller capabilities. I am working on a small fixed budget so I need to make sure I purchase the right items on the first go around. I am trying to regulate 4 fluids. I need to be able to control the flow of each fluid independent of the other fluids. I.e. each solenoid valve needs to be able to be controlled at a frequency independent of the other valves. I am trying to use a PWM like effect for the valve control.

Will the parts I listed in my first post allow me to achieve my desired results? --> independently controlling the flow rate of 4 fluids using PWM to power solenoid valves. Also, would the mosfet or relay modules be better (if the TinkerKit is the right way to go).

I liked the TinkerKit because evey thing appears to be plug and play. I am on a time crunch so paying a small premium to save me some time is acceptable.

Thanks.

Chagrin: See http://www.instructables.com/id/Controlling-solenoids-with-arduino/ for one example.

You could also achieve this with the Mosfet Module which is essentially just a board containing the parts described in the tutorial above.

Any Arduino is fast enough to handle this type of activity. As Lefty mentions an Arduino is capable of switching a transistor or mosfet at a rate much faster than the solenoid can move; you'll be capable of tuning it to hold the solenoid between fully closed and fully open.

Thanks.

Do you know if the parts I listed in my first post would work well for my application?

Yes, those parts would be fine -- except for the Relay shield.

You cannot PWM a relay; these are only capable of handling a finite number of operations and you would wear it out in a few days' time.

Chagrin: Yes, those parts would be fine -- except for the Relay shield.

You cannot PWM a relay; these are only capable of handling a finite number of operations and you would wear it out in a few days' time.

So the TinkerKit Mosfet Module is what I will need, correct?

And thanks!

Will the parts I listed in my first post allow me to achieve my desired results? --> independently controlling the flow rate of 4 fluids using PWM to power solenoid valves.

Solenoids are normally designed to be just be a fully on or fully off device. They are not normally characterized for 'modulated' operation via PWM or analog control. Control values coupled to linear actuators are what are normally used to control flow rates, and together called a control valve. So you are kind of on your own, I won't say you can't get a on/off solenoid to control flow rates with with variable PWM values, but you will have to spend much time experimenting and characterizing the flow rate Vs PWM rate, etc.

Good luck;

Lefty

retrolefty: Good luck;

Lefty

Much appreciated.