# US 10,122,282 B2 · Isolation of secondary transformer winding current during auxiliary power supply generation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,122,282 B2 - Document ID: US10122282B2 - Status: Granted - Kind: B2 - Application number: 15/336,835 - Filed: 2016-10-28 - Published: 2017-02-16 - Granted: 2018-11-06 - Earliest claimed: 2011-12-14 - Assignees: Philips Lighting Holding B.V. - Applicants: Philips Lighting Holding B.V. - Inventors: John L. Melanson; Prashanth Drakshapalli; Siddharth Maru - Web page: https://patentgrep.com/patent/US10122282B2 ## CPC - H05B 45/385: using flyback topology - H02M 1/4258: {using a single converter stage both for correction of AC input power factor and generation of a regulated and galvanically isolated DC output voltage (H02M1/4241 takes precedence)} - H02M 1/44: Circuits or arrangements for compensating for electromagnetic interference in converters or inverters - H02M 3/33507: {with automatic control of the output voltage or current, e.g. flyback converters (H02M3/33561, H02M3/33569 take precedence)} - H02M 3/33523: {with galvanic isolation between input and output of both the power stage and the feedback loop} - H02M 5/2576: {with digital control} - H02M 7/217: using semiconductor devices only - H05B 45/10: Controlling the intensity of the light - H02M 1/0006: {Arrangements for supplying an adequate voltage to the control circuit of converters} - H02M 1/0048: {Circuits or arrangements for reducing losses (using snubbers H02M1/34)} - H02M 3/33561: {having more than one ouput with independent control} - H02M 3/33576: {having at least one active switching element at the secondary side of an isolation transformer} - Y02B 20/30: Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED] - 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 - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - 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 electronic system and method include a controller to actively control power transfer from a primary winding of a switching power converter to an auxiliary-winding of an auxiliary power supply. The switching power converter is controlled and configured such that during transfer of power to the auxiliary-winding, the switching power converter does not transfer charge to one or more secondary-windings of the switching power converter. Thus, the switching power converter isolates one or more secondary transformer winding currents from an auxiliary-winding current. By isolating the charge delivered to the one or more secondary-windings from charge delivered to the auxiliary-winding, the controller can accurately determine an amount of charge delivered to the secondary-windings and, thus, to a load. ## Claims ### Claim 1 An apparatus comprising: a flyback type switching power converter, wherein the switching power converter includes a transformer having a primary-winding, a secondary-winding, and an auxiliary-winding; a first switch coupled to the primary-winding; an auxiliary power supply that includes auxiliary power supply control circuitry coupled to the auxiliary-winding; and a controller coupled to the first switch configured to provide a control signal and configured to (i) control the first switch and current in the primary winding and (ii) control the auxiliary power supply circuitry to isolate a transfer of energy from the primary-winding to the secondary-winding from a transfer of energy from the primary-winding to the auxiliary-winding, wherein the auxiliary power supply having the auxiliary-winding provides auxiliary power to the controller that provides the control signal to control the transferring of energy from the primary-winding, and the secondary-winding delivers energy for a load of the switching power converter, and a capacitor coupled to the controller and to a Zener diode, and a supply voltage node for the controller coupled to the Zener diode, wherein the capacitor and Zener diode are coupled to a current control node of the second switch. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the auxiliary power supply control circuitry comprises the auxiliary-winding, a diode coupled to a first terminal of the auxiliary-winding, and a second switch coupled to the diode. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein the capacitor stores charge to maintain an approximately constant supply voltage for controller. ### Claim 4 (depends on 1) The apparatus of claim 1 wherein the controller depletes charge from the capacitor when the auxiliary power supply is not operating. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the controller is configured to at least control a transfer of energy from the primary winding of the transformer to the secondary-winding of the switching power converter and to the auxiliary-winding for the auxiliary power supply during mutually exclusive periods of time. ### Claim 6 (depends on 5) The apparatus of claim 5 wherein the periods of time comprise successive switching cycles of a switch that controls the transferring of energy from the primary-winding. ### Claim 7 (depends on 5) The apparatus of claim 5 wherein the controller is configured to at least control a first value of a reflected voltage of the auxiliary-winding of the transformer to be lower than a reflected voltage of the secondary winding of the transformer during transfer of energy to the auxiliary-winding and controlling a second value of the reflected voltage of the auxiliary. ### Claim 8 (depends on 1) The apparatus of claim 1 wherein the controller is configured to cause the first switch to conduct current flow in the auxiliary-winding of the transformer; and cause the first switch to stop conducting current flow in the auxiliary-winding of the transformer and allow current to flow in the secondary-winding of the transformer. ### Claim 9 (depends on 8) The apparatus of claim 8 wherein the controller is configured to control the first switch to conduct current flow in the secondary-winding of the transformer until a pre-determined threshold is reached. ### Claim 10 (depends on 1) The apparatus of claim 1 wherein the controller is further configured to: during a first period, control the transfer of energy from the primary-winding of the transformer to the secondary-winding; and during a second period of time, control transfer of energy from the primary-winding to the auxiliary-winding, wherein the first time period and the second time period are mutually exclusive. ### Claim 11 (depends on 1) The apparatus of claim 1 wherein the controller receives a control signal from a dimmer to modify the transfer of energy to the load. ### Claim 12 (depends on 11) The apparatus of claim 11 wherein the dimmer is a triac-based dimmer. ### Claim 13 (depends on 11) The apparatus of claim 11 wherein the load is a lamp.