How this thing works? It is electric water boiler. It is obvious that it converts electric energy to heat making water increase in temperature until it reaches 100 degree Celsius. That is not my question though. What I want to know is how can it shut off itself after reaching that point. Chance of micro-controller to detect temperature is very slim.
I first got curious about electric rice cooker a long time ago. I came to know that it uses weight as shut off mechanism. It has built-in weight sensor to monitor. It will keep heating until all water in mixture are evaporated. Then turn off the switch when the weight changes become insignificant.
Thanks to this invention. We can set it and forget it. Do other more useful jobs without worrying that our rice will get burnt or get under-cooked. Rather watched our favorite movie without interruption, or go to neighbor for three hours, to gossip.
Rice cooker can also be used for other dish, as long as it contain reasonable amount of water. Not for frying and broiling of course. Can be used to boil plain water and prepare coffee.
However, leaving it unattended is a no no. It will keep boiling to dryness. A water kettle equipped with a whistle fits the purpose. It will alert you like an alarm when running boil is reached.
There is another useful device for this. The electric water boiler with a auto shut off feature. It is cheap. I am sure you can afford it. It uses electricity but only use enough to boil what is needed. No keep hot function like air pot and hot/cold water dispenser.
I also got curious with this little contraption. However, not enough to break it open. My wife will surely got angry. She always do whenever I bought gadget only to break open.
A short observation. The device shuts off itself upon reaching running boil. The switch fails triggering off when lid is open. When lid is closed and boiling at the same time, the switch can be pushed on but turns back off immediately after release.
I assume, the off button is triggered by water vapor pressure. Enough to push the device off when pressure builds up. No pressure is maintained if the lid is open.
Keeping the lid open allow us cook camote and eggs.