# US 2015/0341996 A1 · Relating to Power Adaptors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2015/0341996 A1 - Document ID: US20150341996A1 - Status: Published application - Kind: A1 - Application number: 14/818,540 - Filed: 2015-08-05 - Published: 2015-11-26 - Earliest claimed: 2008-10-08 - Assignees: HOLDIP Limited - Applicants: HOLDIP Limited - Inventors: David Thomas Summerland; Charles Pollock; Helen Pollock - Web page: https://patentgrep.com/patent/US20150341996A1 ## CPC - H05B 45/39: Circuits containing inverter bridges - H02M 7/538: in a push-pull configuration (H02M7/5375 takes precedence {; with oscillating arrangements H02M7/53832, H02M7/53846}) - H05B 45/10: Controlling the intensity of the light - H05B 45/382: with galvanic isolation between input and output - 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 A power adaptor (20) is provided, comprising an input (22) for connection to an AC power supply, and a resonant circuit (34) coupled to the input (22) that provides an output suitable for driving a load (50). The capacitance and inductance of the resonant circuit (34) are selected to provide a pre-determined change in effective voltage, and a corresponding pre-determined change in effective current, between the input (22) and the output (24) of the power adaptor (20). ## Claims ### Claim at position 1 1-34. (canceled) ### Claim 35 A power adaptor for one or more solid state light sources comprising an input for connection to an AC power supply, and an LCL series-parallel resonant circuit coupled to the input that provides an output suitable for driving the one or more solid state light sources, wherein the lighting unit includes a controller and electronic switches for driving the resonant circuit, the controller being adapted to use on-time modulation of the switches to determine the waveform of the current drawn from the input by the resonant circuit. ### Claim 36 (depends on 35) A power adaptor as claimed in claim 35, wherein the LCL series-parallel resonant circuit has a first resonant frequency that provides, at a given input voltage, a constant current output that is independent of the load, and a second resonant frequency that provides, at a given input voltage, a current that varies with load, the second resonant frequency providing a significantly greater power at the output, relative to the first resonant frequency, and the controller of the power adaptor being adapted to switch between the resonant frequencies. ### Claim 37 (depends on 35) A power adaptor as claimed in claim 35, wherein the resonant circuit is configured to provide an output having a substantially constant voltage, which is pre-determined for a particular effective voltage of the AC power supply. ### Claim 38 (depends on 37) A power adaptor as claimed in claim 37, wherein the resonant circuit is preferably configured to either boost (ie raise) or buck (ie lower) the actual voltage received at the input of the power adaptor, in order to provide a substantially constant voltage, which is pre-determined for a particular effective voltage of the AC power supply, for the majority of the input AC cycle. ### Claim 39 (depends on 35) A power adaptor as claimed in claim 35, wherein the power adaptor is adapted to turn off the output, when the load is insufficient to be driven by the output provided by the power adaptor, and then turn on the output when the load is sufficient to be driven by the output provided by the power adaptor. ### Claim 40 (depends on 35) A power adaptor as claimed in claim 35, wherein the resonant circuit is adapted such that at one of its resonant frequencies, the power adaptor provides a constant current output, at a given effective input voltage, and the resonant circuit is driven at that resonant frequency or a sub-harmonic thereof, or sufficiently near to that resonant frequency or a sub-harmonic thereof. ### Claim 41 (depends on 35) A power adaptor as claimed in claim 35, wherein the capacitance of the LCL series-parallel resonant circuit is selected with a reactance XC1 to match a required load resistance RL and a required input resistance Rin for the resonant circuit. ### Claim 42 (depends on 41) A power adaptor as claimed in claim 41, wherein the capacitance is selected with a reactance that is equal to the square-root of the product of the required load resistance RL and the required input resistance Rin for the resonant circuit. ### Claim 43 (depends on 35) A power adaptor as claimed in claim 35, wherein the resonant circuit is configured to provide an output having an increased current relative to the current through a resonant inductor, such that the output has a correspondingly decreased effective voltage relative to the effective voltage of the power supply. ### Claim 44 (depends on 35) A power adaptor as claimed in claim 35, wherein the controller comprises an integrated circuit. ### Claim 45 (depends on 35) A lighting unit comprising a power adaptor as claimed in claim 35 and one or more solid state light sources. ### Claim 46 (depends on 45) A lighting unit as claimed in claim 45, wherein the lighting unit is suitable for direct connection to a mains supply, and the light output from the one or more solid state light sources is controllable by varying the power available at the input of the power adaptor.