Neodymium magnet pinch coil...

[CluelessGuy]

I have a practical question. I want to make a rubber (silicone) hose/plug that is pinched closed by two magnets ( very strong magnets such as ones from a hard drive the Neodymium kind). I want to place then into a coil and when I want the liquid to flow, I want to turn on the coil and have the magnets pull apart for a few seconds. (1-5 seconds) then turn the coil off and have them snap closed to stop the flow. This is meant to be repeated 100 times a day with no adverse effect on the magnets original snap together. (note: the plan is to mold the magnets into the rubber to keep them from flipping or falling out or moving)

My questions:
1. Is this possible to do?
2. is there a better method of doing this? (ie- low voltage electromagnet on all the time to keep together then reverse to open? Failures in power seem to be an issue)
3. will the magnets ever fail to snap back or de-magnetize?
4. Will a single coil do this or will it require half a coil and the other half coil due to the magnets being +- when snapped together?
5. will a coil get too hot or require a coil that is so big it isn't practical?

[Bender]

1. no

2. what you want is a peristaltic valve: take a motor with an eccentric camshaft to open or close the hose, much easier and requires no power in on or off position

3. In the configuration you suggest, de-magnetizing one of the magnets will be required to open the valve

4. Configurations with only one magnet and a coil work much better, you could use e.g. a spring to pinch the hose and a coil to push the magnet into the spring, but see 2

5. Possibly. You need a pretty big coil to demagnetise a Neodymium magnet.

Edited March 16, 2017 by Bender