eem2am
Banned
Hello,
We design domestic water temperature controlled showers.
Stepper motors adjust hot and cold flow rates.
If the water in the pipes is ice, and we try and rotate the stepper valves, these valves break.
So do you know how we can detect if the water is ice or liquid.?
...its not terribly useful to use a thermistor....anyway, we already have a thermistor in the "mixed" pipe outlet....since water can be at zero degrees and liquid if it is agitated ....(made to flow a bit)
...the problem is that if our thermistor reads zero degrees or therabouts, we don't know if its ice or water....and we have to disallow the shower form turning on.....and customers are unhappy when there shower does not work.
I was thinking that we could put like a small rotary "fan" in the water pipe, and energise it.........we could then measure the current flow to it to see if the water was ice or not....because if it was ice, then the "fan" would not be able to rotate and it would be in "locked rotor" state.....as such ...would more current flow to its coils?
...i would have thought so , since the back EMF would be lower.(?)
....because if less electric current did flow, then we could measure this current to assess whether we had ice or liquid water in the pipes.?
We design domestic water temperature controlled showers.
Stepper motors adjust hot and cold flow rates.
If the water in the pipes is ice, and we try and rotate the stepper valves, these valves break.
So do you know how we can detect if the water is ice or liquid.?
...its not terribly useful to use a thermistor....anyway, we already have a thermistor in the "mixed" pipe outlet....since water can be at zero degrees and liquid if it is agitated ....(made to flow a bit)
...the problem is that if our thermistor reads zero degrees or therabouts, we don't know if its ice or water....and we have to disallow the shower form turning on.....and customers are unhappy when there shower does not work.
I was thinking that we could put like a small rotary "fan" in the water pipe, and energise it.........we could then measure the current flow to it to see if the water was ice or not....because if it was ice, then the "fan" would not be able to rotate and it would be in "locked rotor" state.....as such ...would more current flow to its coils?
...i would have thought so , since the back EMF would be lower.(?)
....because if less electric current did flow, then we could measure this current to assess whether we had ice or liquid water in the pipes.?