Drip Governor - A most valuble first hack

[erikk]

A couple more designs, one worked for a while until the coil broke unexpectedly

#1
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The water comes in from the back, just off the centre (the aligning pin that attaches to the magnet needs to be centre).

The orientation of the valve lets gravity hold the magnet off of the o ring while its flowing, until you pulse the coil to get the magnet to stick to the o ring. The flow direction sucks the magnet to the o ring, so it stays until you pulse the coil in the opposite direction to open it again.
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The parts: (they're not exactly right but close):
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The coil/magnet wasn't being used as efficiently as it could, so it will hopefully use less power. (this one took 15V and 0.5A) Although this was only a pulse to get it to go from open to closed and vise versa. But the next one I tried pushing the limits of low power.

#2
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This one uses a piece of sheet plastic that bends onto an o ring to seal. The coil makes the magnets push onto the sheet to break the seal. This one didn't seem to have enough pressure from the flow to hold it shut consistently, but when I helped it seal, the coil pushed it open with 5V 0.17A.

I'm hoping a larger o ring will get more force to hold it shut, or maybe I just need to get the sheet positioned better.