Patent ID: 6772752
Filing Date: 2004-08-10
Classification: F24C

Abstract:
A cooking appliance comprising:an oven cavity; a heating system including at least one heat source positioned to develop a heated atmosphere within the oven cavity; a control panel arranged adjacent to the oven cavity, said control panel including a plurality of control elements for inputting control parameters for a cooking operation; and a cooling system provided to establish a cooling airflow being directed, at least in part, along the control panel, said cooling system including: a cooling fan having a drive shaft operatively connected to a fan blade; a multi-pole magnet mounted for rotation with the drive shaft; a Hall effect sensor positioned proximate to the multi-pole magnet, said Hall effect sensor generating a plurality of pulses as the drive shaft rotates; and a controller linked to both the control panel so as to receive the control parameters to establish the cooking operation, and the Hall effect sensor so as to receive the plurality of pulses, wherein the controller calculates a cooling fan speed based on the plurality of pulses generated by the Hall effect sensor, with said cooling fan speed being indicative of a presence of a cooling airflow in the cooling system, said controller terminating the cooking operation when the calculated cooling fan speed is outside a predetermined range.