# US 11,451,155 B2 · Power generation and ZVS control in a power supply > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,451,155 B2 - Document ID: US11451155B2 - Status: Granted - Kind: B2 - Application number: 16/945,989 - Filed: 2020-08-03 - Published: 2022-02-03 - Granted: 2022-09-20 - Earliest claimed: 2020-08-03 - Assignees: Infineon Technologies Austria AG - Applicants: Infineon Technologies Austria AG - Inventors: Wee Tar Richard Ng; Zan Wang; Xiang Yuan - Web page: https://patentgrep.com/patent/US11451155B2 ## CPC - H02M 3/33569: {having several active switching elements (H02M3/3353 takes precedence)} - H02M 3/01: {Resonant DC/DC converters} - H02M 3/33523: {with galvanic isolation between input and output of both the power stage and the feedback loop} - H02M 1/0058: {by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero (using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826)} - H02M 1/0064: {Magnetic structures combining different functions, e.g. storage, filtering or transformation} - Y02B 70/10: Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes - H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P) - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract An apparatus comprises a controller operative to: i) monitor a resonant voltage associated with a primary winding magnetically coupled to a secondary winding; ii) control a flow of current through the primary winding to produce an output voltage at the secondary winding; and iii) control magnetization of the primary winding with respect to a detected a zero crossing event associated with the monitored resonant voltage. The controller further controls a duration of activating a switch coupled to an auxiliary winding (which is magnetically coupled to the primary winding) based on a magnitude of the monitored resonant voltage and/or a magnitude of an input voltage supplied to the primary winding. The controller operates in different modes of magnetizing the primary winding such as at peaks or valleys of the monitored resonant voltage depending on a magnitude of the input voltage. ## Claims ### Claim 1 An apparatus comprising: a controller operative to: monitor a resonant voltage associated with a primary winding magnetically coupled to a secondary winding, the resonant voltage received from an auxiliary winding magnetically coupled to the primary winding; control a flow of current through the primary winding to produce an output voltage at the secondary winding; and control current through the auxiliary winding in response to a detected zero crossing event associated with the monitored resonant voltage, the control of the current through the auxiliary winding controlling magnetization of the primary winding. ### Claim 2 (depends on 1) The apparatus as in claim 1, wherein the resonant voltage occurs due to parasitic capacitance and inductance associated with the primary winding and a first switch in series with the primary winding, the first switch operative to control the flow of current through the primary winding. ### Claim 3 (depends on 1) The apparatus as in claim 1, wherein the controller is further operative to select which of multiple zero crossing events of the monitored resonant voltage to use as a trigger following a first detected zero crossing event to control magnetization of the primary winding, the trigger depending on a magnitude of a load powered by the output voltage. ### Claim 4 (depends on 1) The apparatus as in claim 1, wherein the controller is further operative to control the magnetization of the primary winding at a subsequent peak voltage of the monitored resonant voltage following the detected zero crossing event. ### Claim 5 (depends on 4) The apparatus as in claim 4, wherein the subsequent peak voltage is a next peak voltage of the monitored resonant voltage following the detected zero crossing event. ### Claim 6 (depends on 1) The apparatus as in claim 1, wherein the controller is further operative to magnetize the primary winding at a peak magnitude of the monitored resonant voltage following the zero crossing event. ### Claim 7 (depends on 1) The apparatus as in claim 1, wherein the controller is further operative to: activate a switch after a determined delay time with respect to detecting the zero crossing event, activation of the switch pre-magnetizing the primary winding. ### Claim 8 (depends on 7) The apparatus as in claim 7, wherein the determined delay time is substantially 75% of a resonance period of the monitored resonant voltage. ### Claim 9 (depends on 7) The apparatus as in claim 7, wherein the controller is operative to control a duration of activating the switch based on a magnitude of the monitored resonant voltage. ### Claim 10 (depends on 7) The apparatus as in claim 7, wherein the controller is operative to control a duration of activating the switch based on a magnitude of the monitored resonant voltage and a magnitude of an input voltage supplied to the primary winding. ### Claim 11 (depends on 1) A power supply comprising: a switch controlled by the controller as in claim 1, a state of the switch operative to control the flow of current through the primary winding; and a transformer including the primary winding and the secondary winding in claim 1. ### Claim 12 (depends on 1) The apparatus as in claim 1, wherein the controller is further operative to: activate a first switch after a determined delay time with respect to detecting the zero crossing event, the first switch disposed in series with the auxiliary winding, activation of the first switch controlling the current through the auxiliary winding and the magnetization of the primary winding. ### Claim 13 (depends on 12) The apparatus as in claim 12, wherein the controller is further operative to: control the flow of current through the primary winding via a second switch disposed in series with the primary winding. ### Claim 14 (depends on 12) The apparatus as in claim 12, wherein the determined delay time corresponds to a peak magnitude of the resonant voltage. ### Claim 15 (depends on 12) The apparatus as in claim 12, wherein the controller is further operative to select which of multiple zero crossing events of the monitored resonant voltage to use as a trigger following a first detected zero crossing event to control magnetization of the primary winding. ### Claim 16 (depends on 1) The apparatus as in claim 1, wherein the control of the current through the auxiliary winding pre-magnetizes the primary winding via storage of energy in the primary winding. ### Claim 17 (depends on 1) The apparatus as in claim 1, wherein the controller is further operative to: activate a first switch disposed in series with the auxiliary winding to pre-magnetize the primary winding via storage of energy in the primary winding; and subsequent to pre-magnetizing of the primary winding, and deactivation of the first switch, activate a second switch to control the flow of current through the primary winding and produce the output voltage, the second switch disposed in series with the primary winding. ### Claim 18 (depends on 17) The apparatus as in claim 17, wherein the controller is further operative to: transition the first switch from an OFF state to an ON state at a time in which a magnitude of the resonant voltage at is at a valley. ### Claim 19 (depends on 1) The apparatus as in claim 1, wherein the auxiliary winding is a first auxiliary winding; and wherein the control of current through the first auxiliary winding includes control of current through a second auxiliary winding, the second auxiliary winding magnetically coupled to both the first auxiliary winding and the primary winding. ### Claim 20 An apparatus comprising: a controller operative to: monitor a resonant voltage associated with a primary winding magnetically coupled to a secondary winding; control a flow of current through the primary winding to produce an output voltage at the secondary winding, the flow of current through the primary winding controlled via a first switch disposed in series with the primary winding; control magnetization of the primary winding with respect to a detected zero crossing event associated with the monitored resonant voltage, the monitored resonant voltage generated by a first auxiliary winding magnetically coupled to the primary winding; and wherein the controller is further operative to control the flow of current through the primary winding at a valley magnitude of the monitored resonant voltage following the zero crossing event, the primary winding pre-magnetized via controlled flow of current through a second auxiliary winding magnetically coupled to the primary winding, the controlled flow of current through the second auxiliary winding occurring during deactivation of the first switch to an OPEN state. ### Claim 21 An apparatus comprising: a controller operative to: monitor a resonant voltage associated with a primary winding magnetically coupled to a secondary winding; control a flow of current through the primary winding to produce an output voltage at the secondary winding; and control magnetization of the primary winding with respect to a detected zero crossing event associated with the monitored resonant voltage; wherein the controller is operative to execute a first mode of valley voltage switching of a first switch controlling the flow of current through the primary winding in response to a condition in which a magnitude of an input voltage supplied to the primary winding is less than a threshold value; and wherein the controller is operative to execute a second mode of peak voltage switching of a second switch coupled to an auxiliary winding magnetically coupled to the primary winding in response to a condition in which the magnitude of the input voltage supplied to the primary winding is greater than the threshold value. ### Claim 22 A method comprising: monitoring a resonant voltage associated with a primary winding magnetically coupled to a secondary winding, the resonant voltage received from an auxiliary winding magnetically coupled to the primary winding and the secondary winding; controlling a flow of current through the primary winding to produce an output voltage at the secondary winding; and controlling a flow of current through the auxiliary winding in response to a detected zero crossing event associated with the monitored resonant voltage, the control of the flow of current through the auxiliary winding controlling magnetization of the primary winding. ### Claim 23 (depends on 22) The method as in claim 22, wherein the resonant voltage occurs due to parasitic capacitance and inductance associated with the primary winding and a first switch disposed in series with the primary winding, the first switch operative to control current through the primary winding. ### Claim 24 (depends on 23) The method as in claim 23, wherein controlling magnetization of the primary winding in response to detecting the zero crossing event associated with the monitored resonant voltage includes: controlling activation of a second switch disposed in series with the auxiliary winding. ### Claim 25 (depends on 22) The method as in claim 22, wherein controlling magnetization of the primary winding includes: selecting which of multiple zero crossing events of the monitored resonant voltage to use as a trigger to control switching of the flow of current through the primary winding. ### Claim 26 (depends on 22) The method as in claim 22, wherein controlling magnetization of the primary winding includes: initiating pre-magnetization of the primary winding at a subsequent peak voltage of the monitored resonant voltage following the detected zero crossing event, the pre-magnetization including storage of energy in the primary winding via the flow of current through the auxiliary winding.