I’m trying to find a motorized valve so I can try using an imp to control output water temperature at a plumbing fixture (or entire house). I found this valve and motor combo, but I’m having trouble understanding how I would control valve stem position with the motor (actuator). Is it possible that valve position (0-90 degrees) is set through 0-20mA, or even through the 0-10v and 2-10v listed in the specs? Basically, I’m wondering if someone has a few minutes to write a couple sentences on how an Imp could be used to set and change the position of this valve. I have a lot to learn, but having keywords, ideas and things to study helps me keep focused in learning.
There are probably several ways to do this.
For the easiest and safest connection, I would spend $26 for something like this:
http://www.mikroe.com/click/4-20ma-t/
The Imp uses SPI to command the breakout board to send out 4-20ma to transmitter loop.
4-20ma is a good method because your 2-wire connection (cable length) can be really long length, without voltage drop issues (as with using 0-10VDC).
@mlseim, thank you so much.
Note that with that breakout board, the loop requires 24VDC supply, not AC, but DC.
I wish the valve PDF showed a better example of a control loop using 2-wire 4-20ma
@mlseim, yeah i will watch the AC/DC.
I found that the valve i mentioned is old. Now the valve to look at is Series 193B1606 (or 193B1504 for valve), called model number ARA639. The electrical info is a little better in these pdfs.
http://na.heating.danfoss.com/PCMPDF/ESBE%20ARA%20600%20DS.pdf
http://na.heating.danfoss.com/PCMPDF/ARA_prop.pdf
Thanks for the link to the Click board for 4-20mA output! That seems like a golden idea!
Before I REALLY jump into this project, I still need to review valve/actuator options more. Each time i look into it, an hour at a time, I see another option or two. If I’m reading the specs right, these valves take a little time to respond. I’d love to find a faster valve actuator. Still looking.
