# US 11,910,503 B2 · System and method for determining a characteristic of an input signal > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,910,503 B2 - Document ID: US11910503B2 - Status: Granted - Kind: B2 - Application number: 17/608,107 - Filed: 2020-05-07 - Published: 2022-09-29 - Granted: 2024-02-20 - Earliest claimed: 2019-05-07 - Assignees: Signify Holding B.V. - Applicants: Signify Holding B.V. - Inventors: Poh Keong Ng - Web page: https://patentgrep.com/patent/US11910503B2 ## CPC - H05B 45/375: using buck topology - H05B 45/10: Controlling the intensity of the light - H05B 45/355: Power factor correction [PFC]; Reactive power compensation - H05B 45/3725: Switched mode power supply [SMPS] - Y02B 20/30: Semiconductor lamps, e.g. solid state lamps [SSL] light emitting diodes [LED] or organic LED [OLED] - H05B: ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL - Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS ## Abstract An LED power supply (100) configured to detect a characteristic of an input signal, includes a Buck power factor control circuit (D1, U1, Q1, D2, L1, C1) being configured to receive an input signal, the input signal (VAC) being referenced to a power ground, and to output an output signal, the output signal (Vout) being referenced to an output ground, wherein the output ground is level shifted with respect to the power ground; and a controller (106) configured to output an LED drive signal, the controller referenced to the output ground, wherein the controller is configured to determine the characteristic of the input signal according to a switching time of the Buck power factor control circuit, the switching time of the Buck power factor control circuit being determined by the controller according to a switching signal referenced to the output ground. ## Claims ### Claim 1 An LED power supply configured to detect a characteristic of an input signal, comprising: a Buck power factor control circuit being configured to receive the input signal, the input signal being referenced to a power ground, and to output an output signal, the output signal being referenced to an output ground, wherein the output ground is level shifted with respect to the power ground; and a controller configured to output an LED drive signal, the controller referenced to the output ground, wherein the controller is configured to determine the characteristic of the input signal measuring a plurality of switching times of the Buck power factor control circuit, and determining conduction times and/or conduction frequencies of the Buck power factor control circuit, the plurality of switching times of the Buck power factor control circuit being determined by the controller according to a switching signal referenced to the output ground. ### Claim 2 (depends on 1) The LED power supply of claim 1, wherein the characteristic of the input signal is at least one of: a voltage, a phase angle, and a frequency. ### Claim 3 (depends on 1) The LED power supply of claim 1, wherein the characteristic of the input signal is a phase angle, wherein the controller is further configured to adjust the LED drive signal to dim at least one LED according to the phase angle. ### Claim 4 (depends on 1) The LED power supply of claim 1, wherein the controller is further configured to report the characteristic to a remote server. ### Claim 5 (depends on 1) The LED power supply of claim 1, wherein the plurality of switching times of the Buck power factor control circuit is measured according to a rising edge or falling edge of an envelope of the switching signal. ### Claim 6 (depends on 1) The LED power supply of claim 1, wherein the characteristic is a voltage, wherein the voltage is determined according to a conduction time and a conduction frequency of the switching signal, wherein the conduction time and the conduction frequency of the input signal may be determined from the plurality of switching times of the switching signal. ### Claim 7 (depends on 1) The LED power supply of claim 1, wherein the switching signal is measured as a voltage across or a current through one of: a power MOSFET, a freewheeling diode, or a Buck inductor. ### Claim 8 (depends on 1) The LED power supply of claim 1, wherein switching signal is measured at a secondary winding of a transformer, the secondary winding being referenced to output ground. ### Claim 9 (depends on 8) The LED power supply of claim 8, wherein a primary winding of the transformer is in series with one of: a power MOSFET, a freewheeling diode, or a Buck inductor. ### Claim 10 (depends on 8) The LED power supply of claim 8, wherein a primary winding of the transformer is formed by a Buck inductor. ### Claim 11 (depends on 1) The LED power supply of claim 1, wherein the switching signal is measured at a secondary winding of a transformer, the secondary winding being referenced to output ground, a primary winding of the transformer being formed by a Buck inductor, wherein the plurality of switching times of the Buck power factor control circuit is measured according to a rising edge or falling edge of an envelope of the switching signal. ### Claim 12 A controller being referenced to an output ground of a Buck power factor control circuit, the controller comprising a non-transitory storage medium and a processor that, when executing instructions stored in the non-transitory storage medium, performs steps comprising: receiving a switching signal, the switching signal being referenced to the output ground; measuring, from the switching signal, a plurality of switching times of the Buck power factor control circuit and determining conduction times and/or conduction frequencies of the Buck power factor control circuit; and determining, from the plurality of switching times, conduction times and conduction frequencies, a characteristic of an input signal to the Buck power factor control circuit. ### Claim 13 (depends on 12) The controller of claim 12, wherein the controller is configured to dim at least one LED according to the characteristic of the input signal. ### Claim 14 (depends on 12) The controller of claim 12, wherein the controller is configured to transmit the characteristic to a remote server. ### Claim 15 (depends on 12) The controller of claim 12, wherein the characteristic of the input signal is at least one of: a voltage, a conduction phase, and a frequency.