Hi all,
I think this is a fairy simple circuit I need to build, but I'm not sure. This is my first post here, but I'm SO glad to find these forums.
What I need to do is compare two temperatures, and depending on which one is higher, control a valve (in a solar water system). It is a 3 way valve, which only rotates through 90 degrees.
So, I need to use two thermistors to compare two temperatures. If temp 'A' is higher than temp 'B', then I need my valve actuator in position 'a'. If temp 'B' is higher, then I need my valve actuator in position 'b'. As stated, the valve only rotates through 90 degrees, so my valve actuator (or servo) or whatever I use, only has to rotate 90 degrees.
My thermistors will likely be standard 10Kohm thermistors (I believe that resistance is at 77 degrees F). I dont actually care what the temperature IS, I only care which temp is higher. I'm assuming the temperature part of the circuit is the easy part.
As far as turning the valve...I could use a Goldline actuator 'GVA-24', which apparently runs on 24Vac. However, I have not yet found the specifics on how to control it. I think it is a 3-wire device.
Should I use a servo motor instead? Maybe the Goldline actuator is in fact a servo (?). I realize that whatever I use has to have enough torque to control the existing valve.
If anyone can point me in the right direction, I would appreciate it.
thanks,
Chisolm Wilson
I think this is a fairy simple circuit I need to build, but I'm not sure. This is my first post here, but I'm SO glad to find these forums.
What I need to do is compare two temperatures, and depending on which one is higher, control a valve (in a solar water system). It is a 3 way valve, which only rotates through 90 degrees.
So, I need to use two thermistors to compare two temperatures. If temp 'A' is higher than temp 'B', then I need my valve actuator in position 'a'. If temp 'B' is higher, then I need my valve actuator in position 'b'. As stated, the valve only rotates through 90 degrees, so my valve actuator (or servo) or whatever I use, only has to rotate 90 degrees.
My thermistors will likely be standard 10Kohm thermistors (I believe that resistance is at 77 degrees F). I dont actually care what the temperature IS, I only care which temp is higher. I'm assuming the temperature part of the circuit is the easy part.
As far as turning the valve...I could use a Goldline actuator 'GVA-24', which apparently runs on 24Vac. However, I have not yet found the specifics on how to control it. I think it is a 3-wire device.
Should I use a servo motor instead? Maybe the Goldline actuator is in fact a servo (?). I realize that whatever I use has to have enough torque to control the existing valve.
If anyone can point me in the right direction, I would appreciate it.
thanks,
Chisolm Wilson