# US 2002/0053565 A1 · Microwave oven having overheat preventing function and method of controlling its fan motor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2002/0053565 A1 - Document ID: US20020053565A1 - Status: Published application - Kind: A1 - Application number: 09/781,313 - Filed: 2001-02-13 - Published: 2002-05-09 - Earliest claimed: 2000-11-08 - Assignees: Samsung Electronics Co., Ltd. - Inventors: Sung-Ho Lee; Young-Won Cho; Tae-Soo Kim - Web page: https://patentgrep.com/patent/US20020053565A1 ## CPC - H05B 6/642: {Cooling of the microwave components and related air circulation systems (H05B6/6473 takes precedence)} - H05B 6/666: {Safety circuits (emergency protective circuits in general H02H)} - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract Disclosed is a microwave oven capable of cooking food according to an output mode in response to an output level of its magnetron, including a fan motor having a low-speed node and a high-speed node to receive power, and having a turning speed variable in response to a node connecting state; an output mode selecting part through which one of output modes is selected; a switching part having at least one switch for switching power applied to the low-speed node or high-speed node of the fan motor; and a control unit controlling the switching part in response to an output mode selected by the output mode selecting part, thus preventing its electrical components from being overheated. ## Claims ### Claim 1 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 low-speed node and a high-speed node to receive power, and having a turning speed variable in response to a node connecting state; an output mode selecting part through which one of output modes is selected; switching means having at least one switch for switching power applied to the low-speed node or high-speed node of the fan motor; and control means controlling the switching means in response to an output mode selected by the output mode selecting part. ### Claim 2 (depends on 1) A microwave oven according to claim 1, wherein the switching means has first and second relays each connected to a power line, and the first relay and the second relay are connected to the low-speed node and the high-speed node, respectively. ### Claim 3 (depends on 1) A microwave oven according to claim 1, wherein the switching means has a relay connected to a power line, and the relay is selectively connected to the low-speed node or high-speed node. ### Claim 4 (depends on 1) A microwave oven according to claim 1, wherein the fan motor has a primary driving winding and a secondary driving winding, and the high-speed node is connected between the primary driving winding and the secondary driving winding. ### Claim 5 (depends on 4) A microwave oven according to claim 4, wherein the primary driving winding has the number of turns larger than the secondary driving winding, and is of a diameter smaller than the secondary driving winding. ### Claim 6 (depends on 1) A microwave oven according to claim 1, further comprising a switch for driving the fan motor if the magnetron stops operating. ### Claim 7 (depends on 6) A microwave oven according to claim 6, wherein the switch has a main relay connected between the power line and the fan motor, and the main relay is turned on in response to a control signal from the control means. ### Claim 8 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. ### Claim 9 (depends on 8) A microwave oven according to claim 8, wherein the control means increases the fan motor's turning speed as the magnetron's output level is raised. ### Claim 10 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. ### Claim 11 (depends on 10) A method according to claim 10, wherein the step of performing the cooking according to the high-output mode includes the sub-steps of: (d) driving the magnetron in a high-output level; (e) driving the fan motor at high speeds by applying the power to the fan motor's high-speed node; (f) checking if the high-output mode is completed; and (g) if the high-output mode is completed in the step (f), stopping the magnetron's operation. ### Claim 12 (depends on 10) A method according to claim 10, further comprising the steps of: (h) determining if a deodorization mode is set up after the step (b) or (c) has been performed; (i) turning on a main relay if the deodorization mode is set up in the step (h); (j) driving the fan motor by applying the power to the fan motor's low-speed node or high-speed node; (k) determining if the deodorization mode is completed; and (l) if the deodorization mode is completed in the step (k), turning off the main relay. ### Claim 13 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. ### Claim 14 (depends on 13) A method according to claim 13, further comprising the steps of: setting up a deodorization mode after cooking food has been completed in the desired output level; if the deodorization mode is set up, driving the fan motor at a desired turning speed by applying the power to a desired input terminal of the fan motor having a plurality of input terminals; and if the deodorization mode is completed, stopping the fan motor's operation. ### Claim 15 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. ### Claim 16 (depends on 15) A method according to claim 15, wherein the deodorization mode is performed by applying the power to one of the fan motor's plural input terminals, corresponding to a desired deodorization speed.