Yep, this is another in the "not earth-shattering" series of ideas.

Automatic shut-off coffee makers are available, but they don't make much sense. They operate on a timer, which shuts the unit off after 60 or 120 minutes or whatever. Sure, that will prevent a meltdown or a dry boil, but only if you're already starting with a pretty full pot of joe. You could put an almost-empty pot on the heater base and it would cook dry within the time allotted.

Instead, put a weight sensor in the base of the unit. Set the threshhold weight to be the pot plus, say, 1/2 cup fluid. If the fluid level gets too low, the switch goes to the off position.

This would work for either the home coffee maker (auto drip type of thing) or for the industrial strength restaurant style.

Yes, I've google searched. All I've found are the timed shut-off type. No weight-based ones.
-- quarterbaker, Dec 18 2001

genius, but I wish it exploded or something <help - hanging around with Afro does one no good at all>
-- po, Dec 18 2001


Croissant. This way my Mom can stop calling me from work and telling me to make sure she turned the coffee machine off. And the smokeless ashtray, that really doesn't work.
-- jimithing, Dec 18 2001


While "not-earh-shattering" this idea is an infinite improvement over the current design. Auto-shut off has been around for years, yet no one ever before proposed this far superior engineering of it. That makes you a "non-linear" thinker, and the recipient of a croissant.
-- dana_renay, Dec 18 2001


If non-linear thinking is all it takes to get a croissant around here...
-- beauxeault, Dec 18 2001


can you do non-linear, can you, can you? go on then
-- po, Dec 18 2001


I likey but wouldn't the machine shut off every time you grabbed the pot?
-- 2 fries shy of a happy meal, Sep 02 2004


Good, but perhaps it might work better if it detected the slight rise in temperature that is bound to occour when the liquid coffee quits moderating the temperature. Perhaps an extra circuit that keeps up with the cycle rate of the thermostat.
-- Bull Winkus, Jan 04 2005


surely it just needs to measure the rate of change of weight ? (it should only do this once the liquid is boiling however, otherwise it'll never even warm up). nice work [1/4]Ber
-- neilp, Jan 05 2005


Boiling? Your coffee maker must run a good deal warmer than mine.
-- bristolz, Jan 05 2005


Since the pot has to start out emtpy, it would be simplest to use a temperature sensor, or to put the weight sensor under the entirety of the machine.

I tend to spill coffee on the hot plate, which could theoretically for a pretty thick coating after a while. A temperature sensor would probably cut out sooner in this situation, which would be annoying but safer.
-- tiromancer, Jan 05 2005


Given a fixed heating power, the smaller the volume of fluid in the pot, the higher the equilibrium temperature achieved. For this reason I too favour a temperature sensor.
-- vincevincevince, Nov 10 2007



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