Boil dry detection in cooking appliances

A boil dry detection system for a cooking appliance having at least one energy source disposed under a cooking surface and a power source for providing a variable level of power to said energy source, said system comprising:

• a temperature sensor providing a temperature signal representative of the temperature of said cooking surface;
• means for controlling said level of power being supplied to said energy source, said means for controlling providing a power signal that is indicative of said level of power being supplied to said energy source;
• means for selectively generating an estimate of the first and second derivatives with respect to time of either one of said temperature signal or said power signal;
• means for producing the cross-correlation of said first and second derivative estimates;
• and
• means for providing a boil dry indication when said cross-correlation exceeds a predetermined threshold.

A method of detecting a boil dry condition in a utensil being heated on a cooking appliance having at least one energy source, said method comprising the steps of:

• providing a signal representative of at least one parameter associated with said cooking appliance;
• generating an estimate of the first and second derivatives of said signal with respect to time;
• producing the cross-correlation of said first and second derivative estimates;
• and
• providing a boil dry indication when said cross-correlation exceeds a predetermined threshold.