Patent ID: 7745759
Filing Date: 2010-06-29
Classification: A47J

Abstract:
1. An electrically powered heated kettle comprising an unsealed vessel for holding a vaporizable liquid, a heater capable of heating the liquid in said vessel to the boiling point of the liquid at the prevailing atmospheric pressure, an electrical heater controller to adjust the amount of power delivered to said heater, an electronic signal processor to direct said controller to adjust the amount of electrical power to said heater, an electrical sensor located to generate an electrical signal that varies predictably with the temperature of the liquid or the air/vapor mixture directly adjacent the liquid in said vessel as the liquid is heated by said heater to the boiling point, and to transmit said signal to said electrical signal processor, whereby said processor can determine the instant in time that the rate of rise of liquid temperature essentially goes to zero and can therefore establish that the liquid is boiling and direct said controller to reduce the amount of electrical power delivered to said heater.