Microwave oven having overheat preventing function and method of controlling its fan motor

A microwave oven capable of cooking food according to an output mode in response to an output level of its magnetron, comprising:

• a fan motor having a plurality of nodes as a power input terminal, and having a turning speed variable upon receipt of a power through said nodes;
• an output mode selecting part through which one of plural output modes is selected;
• switching means for switching the power applied to the fan motor's input terminal;
• and
• control means controlling the switching means in order to set up the fan motor's turning speed in response to an output level of the magnetron corresponding to an output mode selected by the output mode selecting part.

A method of controlling a fan motor for a microwave oven capable of cooking food according to an output mode in response to an output level of its magnetron, comprising the steps of:

• (a) determining if an output mode is selected;
• (b) if a low-output mode is selected in the step (a), performing a cooking according to the low-output mode by applying a power to the fan motor's low-speed node;
• and
• (C) if a high-output mode is selected in the step (a), performing a cooking according to a high-output mode by applying the power to the fan motor's high-speed node.

A method of controlling a fan motor for a microwave oven capable of cooking food according to an output mode in response to an output level of its magnetron, comprising the steps of:

• selecting a user-desired output mode through a key input part;
• driving the magnetron according to an output level corresponding to the selected output mode;
• and
• switching a power applied to the fan motor's input terminal so as to increase the fan motor's turning speed as the magnetron's output level is increased.

A method of controlling a fan motor for a microwave oven capable of cooking food according to an output mode in response to an output level of its magnetron, comprising the steps of:

• (1) selecting desired one of plural output modes;
• (2) if a low-output mode is selected in the step (1), performing a cooking according to the low-output mode by applying a power to a low-speed node of the fan motor's plural input terminals;
• (3) if a high-output mode is selected in the step (1), performing a cooking according to the high-output mode by applying the power to a high-speed node of the fan motor's plural input terminals;
• and
• (4) after cooking food according to the low-output mode or high-output mode has been completed, performing a deodorization mode to remove the smell produced by cooking the food to the outside.