I have a little electric rice cooker, with only one control: a “start” button. It cooks all sorts of rice properly, no matter how long the rice needs to be cooked (between 20 and 60 mintues). It never overcooks white rice or undercooks brown rice. It has neither timer nor setting for different rices. On the inside is an removable aluminum pan. Maybe there’s a weight sensor underneath the pan? I can’t tell.
This is a bottom-of-the-line entry among rice cookers. How does it know how long to cook?
It has a thermostat that will switch off when the pot gets to hot. When there is water in the pot it cannot get hotter than boiling water. When the water is gone the pot can heat up then the heater turns off. However the amount of energy to get the bottom of the pot hot is not enough to burn the rice.
I am always marvelled by the inventions of the white man. I mean you put a hot beverage in a thermos flask and it knows to keep it piping hot. You put a cold beverage and it knows to keep it ice cold. How the heck does it know? Progress is a great thing. Sciences advance more than we ever thought possible. What will they think of next? ^_*
Thermos flasks have embedded thermistors that measure the inside and outside temperatures. When the inside temperature is high (such as the case with coffee or soup), the vacuum-assisted insulation is electrically polarized to keep heat in. When the inside temperature is low (such as the case with milk or ice), the polarization of the insulation is reversed, thus keeping cold in. The circuit, which is embedded in the bottom of the flask, is powered by a thermopile, thus essentially making it a self-powered/battery-free device. (A thermopile generates electrical power using a temperature difference.)
I know you’re joking, but I’m pretty sure that the rice-cooker was invented in Taiwan. For all of my Taiwanese friends, the rice-cooker is an indispensable kitchen appliance. I remember one conversation which, I swear, went: “Do you eat rice?” “Uh, yeah.” “But you don’t have a rice-cooker.” “Uh… yeah…” “How do you prepare it?” “In a pot, on the stove.” “Does that work?”
