# US 2014/0151365 A1 · Electronic induction heating cooker and output level control method thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0151365 A1 - Document ID: US20140151365A1 - Status: Published application - Kind: A1 - Application number: 14/010,570 - Filed: 2013-08-27 - Published: 2014-06-05 - Earliest claimed: 2012-12-03 - Assignees: LG Electronics Inc. - Inventors: Dooyong OH; Heesuk ROH; Byeongwook PARK - Web page: https://patentgrep.com/patent/US20140151365A1 ## CPC - H05B 6/065: {using coordinated control of multiple induction coils} - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL ## Abstract An electronic induction heating cooker is provided. The electronic induction heating cooker may include a rectifier that rectifies an input voltage into a direct current (DC) voltage and output the DC voltage, an inverter including first, second and third switches connected in series between a positive power source terminal and a negative power source terminal to generate an alternating current (AC) voltage by switching the DC voltage, a first heater driven by the AC voltage so as to heat a first cooking container, a second heater connected in parallel to the first heater and driven by the AC voltage so as to heat a second cooking container, and a switching controller that generates a switching signal for controlling the first and second heaters in accordance with a set of operating conditions input thereto and adjusts a duty cycle of the switching signal. ## Claims ### Claim 1 An electronic induction heating cooker, comprising: a rectifier configured to rectify an input voltage into a direct current (DC) voltage and output the DC voltage; an inverter including first, second and third switches connected in series between a positive power source terminal and a negative power source terminal and configured to generate an alternating current (AC) voltage by switching the DC voltage; a first heater driven by the AC voltage to generate heat for heating a first cooking container; a second heater connected in parallel to the first heater and driven by the AC voltage to generate heat for heating a second cooking container; and a switching controller configured to generate a switching signal for controlling the first and second heaters in accordance with a set of operating conditions input thereto, and to adjust a duty cycle of the switching signal in response to an adjustment in the operating conditions. ### Claim 2 (depends on 1) The electronic induction heating cooker of claim 1, wherein the set of operating conditions comprises: an operation mode condition for designating one of a plurality of operation modes for the first and second heaters; and an output power condition for determining output powers of the first and second heaters. ### Claim 3 (depends on 2) The electronic induction heating cooker of claim 2, wherein the plurality of operation modes comprises: a first operation mode for driving only the first heater; a second operation mode for driving only the second heater; a third operation mode for simultaneously driving both the first and second heaters; and a fourth operation mode for alternately driving the first and second heaters. ### Claim 4 (depends on 3) The electronic induction heating cooker of claim 3, wherein, in response to designating the first operation mode, the switching controller is further configured to: output a first switching signal for controlling the first and second switches to be alternately open and controlling the third switch to either continue to be closed, or to be open or closed in synchronization with the second switch; and adjust ON and OFF periods of the first switching signal in accordance with the output power condition. ### Claim 5 (depends on 4) The electronic induction heating cooker of claim 4, wherein, in response to designating the second operation mode, the switching controller is further configured to: output a second switching signal for controlling the second and third switches to be alternately open and controlling the first switch to continue to be open or closed; and adjust ON and OFF periods of the second switching signal in accordance with the output power condition. ### Claim 6 (depends on 3) The electronic induction heating cooker of claim 3, wherein, in response to designating the third operation mode, the switching controller is further configured to: output a third switching signal for controlling the first and third switches to be alternately open and controlling the second switch to continue to be closed; and adjust ON and OFF periods of the third switching signal in accordance with the output power condition. ### Claim 7 (depends on 5) The electronic induction heating cooker of claim 5, wherein, in response to designating the fourth operation mode, the switching controller is further configured to: alternately output the first and second switching signals at regular intervals of time; and adjust the ON and OFF periods of each of the first and second switching signals in accordance with the output power condition. ### Claim 8 (depends on 7) The electronic induction heating cooker of claim 7, wherein the controller is configured to adjust ON and OFF periods of the first switching signal separately and differently from the ON and OFF periods of the second switching signal. ### Claim 9 A method of adjusting the output power of an electronic induction heating cooker, the electronic induction heating cooker comprising a resonant circuit including first and second heaters and an inverter, the inverter including first, second and third switches connected in series, the method comprising: receiving a first operating condition and determining an operation mode from the received first operating condition; determining a switching signal corresponding to the first operating condition; receiving a second operating condition; determining ON and OFF periods of the switching signal in accordance with the second operating condition; and outputting the switching signal during the ON period. ### Claim 10 (depends on 9) The method of claim 9, wherein determining an operation mode comprises designating at least one of a plurality of operation modes, comprising: designating a first operation mode for driving only the first heater; designating a second operation mode for driving only the second heater; designating a third operation mode for simultaneously driving both the first and second heaters; or designating a fourth operation mode for alternately driving the first and second heaters. ### Claim 11 (depends on 10) The method of claim 10, wherein, in response to designating the first operation mode, determining the switching signal comprises outputting a first switching signal for controlling the first and second switches to be alternately open and controlling the third switch to either continue to be closed, or be open or closed in synchronization with the second switch, and determining ON and OFF periods comprises determining output power of the first heater by adjusting ON and OFF periods of the first switching signal. ### Claim 12 (depends on 11) The method of claim 11, wherein, in response to designating the second operation mode, determining the switching signal further comprises outputting a second switching signal for controlling the second and third switches to be alternately open and controlling the first switch to either continue to be open or closed, and determining ON and OFF periods further comprises determining output power of the second heater by adjusting ON and OFF periods of the second switching signal. ### Claim 13 (depends on 10) The method of claim 10, wherein, in response to designating the third operation mode, determining the switching signal comprises outputting a third switching signal for controlling the first and third switches to be alternately open and controlling the second switch to continue to be closed, and determining ON and OFF periods comprises determining output powers of the first and second heaters by adjusting ON and OFF periods of the third switching signal. ### Claim 14 (depends on 12) The method of claim 12, wherein, in response to designating the fourth operation mode, determining the switching signal further comprises, alternately outputting the first and second switching signals at regular intervals of time, and determining ON and OFF periods further comprises determining the output powers of the first and second heaters by adjusting ON and OFF periods of each of the first and second switching signals, wherein the ON and OFF periods of the first switching signal are adjusted separately and differently from the ON and OFF periods of the second switching signal. ### Claim 15 A method of controlling an electronic induction heating cooker comprising a resonant circuit including first and second heaters and an inverter including first, second and third switches connected in series, the method comprising: receiving a first operating command and designating one of a plurality of operation modes for the first and second heaters based on the received first operating command; determining a switching signal corresponding to the designated one of the plurality of operating modes; receiving a second operating command; determining ON and OFF periods of the switching signal in accordance with the second operating command; and operating the first and second heaters in accordance with the switching signal. ### Claim 16 (depends on 15) The method of claim 15, wherein designating one of a plurality of operation modes for the first and second heaters comprises designating a first operation mode operating only the first heater, and wherein determining a switching signal comprises generating a first switching signal alternately opening the first and second switches and either maintaining a closed position of the third switch or opening or closing the third switch in synchronization with the second switch, and wherein determining ON and OFF periods comprises adjusting ON and OFF periods of the first switching signal to set an output power level of the first heater. ### Claim 17 (depends on 15) The method of claim 15, wherein designating one of a plurality of operation modes for the first and second heaters comprises designating a second operation mode operating only the second heater, and wherein determining a switching signal comprises generating a second switching signal alternately opening the second and third switches and maintaining a position of the first switch, and wherein determining ON and OFF periods comprises adjusting ON and OFF periods of the second switching signal to set an output power level of the second heater. ### Claim 18 (depends on 15) The method of claim 15, wherein designating one of a plurality of operation modes for the first and second heaters comprises designating a third operation mode simultaneously operating the first and second heaters, and wherein determining a switching signal comprises generating a third switching signal alternately opening the first and third switches and maintaining a closed position of the second switch, and wherein determining ON and OFF periods comprises adjusting ON and OFF periods of the first and second switching signals to set output power levels of the first and second heaters. ### Claim 19 (depends on 15) The method of claim 15, wherein designating one of a plurality of operation modes for the first and second heaters comprises designating a fourth operation mode alternately operating the first and second heaters, and wherein determining a switching signal comprises alternately outputting a first switching signal and a second switching signal at regular intervals of time, and wherein determining ON and OFF periods comprises adjusting ON and OFF periods of the first switching signal separately and differently from those of the second switching signal to set an output power level of the first and second heaters. ### Claim 20 (depends on 19) The method of claim 19, wherein the first switching signal comprises alternately opening the first and second switches and either maintaining a closed position of the third switch or opening or closing the third switch in synchronization with the second switch, and the second switching signal comprises alternately opening the second and third switches and maintaining a position of the first switch.