# US 12,114,121 B2 · Method for charging wireless headset, charging circuit and charging case > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,114,121 B2 - Document ID: US12114121B2 - Status: Granted - Kind: B2 - Application number: 17/955,360 - Filed: 2022-09-28 - Published: 2023-12-21 - Granted: 2024-10-08 - Earliest claimed: 2022-06-20 - Assignees: Beijing Xiaomi Mobile Software Co., Tld. - Applicants: Beijing Xiaomi Mobile Software Co., Ltd. - Inventors: Xuede Lv; Jie Fan - Web page: https://patentgrep.com/patent/US12114121B2 ## CPC - H02J 7/60: including safety or protection arrangements - H04R 1/1025: Accumulators specially adapted for earpieces; Arrangements specially adapted for charging thereof - H02J 7/06: using discharge tubes or semiconductor devices - H02J 7/731: {specially adapted for holding portable devices containing batteries (H02J7/751 takes precedence)} - H02J 7/865: {Battery or charger load switching, e.g. concurrent charging and load supply (H02J7/50 takes precedence)} - H02J 7/96: in response to battery voltage - H04R 1/1041: {Mechanical or electronic switches, or control elements (switches in general H01H)} - H04R 2460/17: Hearing device specific tools used for storing or handling hearing devices or parts thereof, e.g. placement in the ear, replacement of cerumen barriers, repair, cleaning hearing devices - H02J: ELECTRIC POWER NETWORKS; CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) ## Abstract A charging circuit is provided. The charging circuit includes a protection circuit and a charging control switch connected in series, and a transfer switch. The transfer switch is configured to switch to a first charging circuit by connecting to the protection circuit, and switch to a second charging circuit by connecting to the charging control switch. A maximum charging voltage of the first charging circuit is lower than a maximum charging voltage of the second charging circuit. ## Claims ### Claim 1 A charging circuit, comprising: a protection circuit and a charging control switch connected in series; and a transfer switch, configured to switch to a first charging circuit by connecting to the protection circuit and configured to switch to a second charging circuit by connecting to the charging control switch, wherein a maximum charging voltage of the first charging circuit is lower than a maximum charging voltage of the second charging circuit. ### Claim 2 (depends on 1) The charging circuit of claim 1, further comprising: a controller, configured to control the transfer switch to be connected to the protection circuit so as to switch to the first charging circuit, or configured to control the transfer switch to be connected to the charging control switch so as to switch to the second charging circuit. ### Claim 3 (depends on 2) The charging circuit of claim 2, wherein the transfer switch is configured to: in response to determining that a voltage difference between an output voltage of a power supply and a charging voltage of a charging load is greater than a first difference threshold, switch to the first charging circuit; and in response to determining that the voltage difference between the output voltage of the power supply and the charging voltage of the charging load is greater than a second difference threshold, switch to the second charging circuit; wherein the second difference threshold is lower than the first difference threshold. ### Claim 4 (depends on 3) The charging circuit of claim 3, wherein the charging load comprises a wireless headset. ### Claim 5 (depends on 1) The charging circuit of claim 1, wherein the transfer switch comprises a single-pole double-throw switch. ### Claim 6 (depends on 1) The charging circuit of claim 1, wherein the transfer switch comprises two single-pole single-throw switches. ### Claim 7 (depends on 1) The charging circuit of claim 1, wherein the protection circuit comprises a first metal oxide semiconductor (MOS) switch circuit and a second MOS switch circuit, and a D pole of the first MOS switch circuit is connected to a D pole of the second MOS switch circuit. ### Claim 8 (depends on 1) The charging circuit of claim 1, wherein the charging control switch comprises a third metal oxide semiconductor (MOS) switch circuit, and an impedance of the protection circuit is greater than an impedance of the charging control switch. ### Claim 9 A charging case, comprising: a charging interface, configured to connect the charging case to a power supply; a charging base, configured to place a wireless headset; and a charging circuit, comprising a protection circuit and a charging control switch connected in series, and a transfer switch; wherein the transfer switch is configured to switch to a first charging circuit by connecting to the protection circuit and configured to switch to a second charging circuit by connecting to the charging control switch; wherein a maximum charging voltage of the first charging circuit is lower than a maximum charging voltage of the second charging circuit. ### Claim 10 (depends on 9) The charging case of claim 9, wherein the charging circuit further comprises: a controller, configured to control the transfer switch to be connected to the protection circuit so as to switch to the first charging circuit, or configured to control the transfer switch to be connected to the charging control switch so as to switch to the second charging circuit. ### Claim 11 (depends on 10) The charging case of claim 10, wherein the transfer switch is configured to: in response to determining that a voltage difference between an output voltage of the power supply and a charging voltage of the wireless headset is greater than a first difference threshold, switch to the first charging circuit; and in response to determining that a voltage difference between the output voltage of the power supply and the charging voltage of the wireless headset is greater than a second difference threshold, switch to the second charging circuit; wherein the second difference threshold is lower than the first difference threshold. ### Claim 12 (depends on 9) The charging case of claim 9, wherein the transfer switch comprises a single-pole double-throw switch. ### Claim 13 (depends on 9) The charging case of claim 9, wherein the transfer switch comprises two single-pole single-throw switches. ### Claim 14 (depends on 9) The charging case of claim 9, wherein the protection circuit comprises a first metal oxide semiconductor (MOS) switch circuit and a second MOS switch circuit, and a D pole of the first MOS switch circuit is connected to a D pole of the second MOS switch circuit. ### Claim 15 (depends on 9) The charging case of claim 9, wherein the charging control switch comprises a third metal oxide semiconductor (MOS) switch circuit, and an impedance of the protection circuit is greater than an impedance of the charging control switch. ### Claim 16 A method for charging a wireless headset with a charging case, comprising: in response to determining that the wireless headset is placed in the charging case, switching to a first charging circuit by controlling a transfer switch to be connected to a protection circuit, and charging the wireless headset by the first charging circuit, wherein the charging case comprises the protection circuit and a charging control switch connected in series, and the transfer switch; and in response to detecting that a voltage difference between an output voltage of a power supply and a charging voltage of the wireless headset is greater than a second difference threshold, switching to a second charging circuit by controlling the transfer switch to be connected to the charging control switch, and charging the wireless headset by the second charging circuit; wherein a maximum charging voltage of the first charging circuit is lower than a maximum charging voltage of the second charging circuit. ### Claim 17 (depends on 16) The method of claim 16, further comprising: in response to detecting a voltage difference between the output voltage of the power supply and the charging voltage of the wireless headset is greater than a first difference threshold, charging the battery in the wireless headset by the first charging circuit; wherein the second difference threshold is lower than the first difference threshold. ### Claim 18 (depends on 16) The method of claim 16, wherein the protection circuit comprises a first metal oxide semiconductor (MOS) switch circuit and a second MOS switch circuit, and a D pole of the first MOS switch circuit is connected to a D pole of the second MOS switch circuit. ### Claim 19 (depends on 16) The method of claim 16, wherein the charging control switch comprises a third metal oxide semiconductor (MOS) switch circuit, and an impedance of the protection circuit is greater than an impedance of the charging control switch. ### Claim 20 (depends on 16) The method of claim 16, wherein the transfer switch comprises a single-pole double-throw switch.