# US 2010/0165686 A1 · Rectifier circuit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2010/0165686 A1 - Document ID: US20100165686A1 - Status: Published application - Kind: A1 - Application number: 12/643,003 - Filed: 2009-12-21 - Published: 2010-07-01 - Earliest claimed: 2008-12-22 - Assignees: Texas Instruments Deutschland GmbH - Inventors: Markus Matzberger; Konrad Wagensohner; Erich-Johann Bayer - Web page: https://patentgrep.com/patent/US20100165686A1 ## CPC - H02M 7/219: in a bridge configuration - 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 A rectifier circuit for use in an energy harvesting application in which mechanical energy is converted into electrical energy by using an AC generator using an active rectifier bridge with a pair of input terminals adapted to be connected to an output of the AC generator and a pair of output terminals, an inductor connected across the output terminals of the active rectifier bridge and a storage capacitor. A pair of output switches selectively connects the storage capacitor across the inductor. A controller controls the active rectifier bridge and the pair of output switches such that in successive switching cycles within any half wave of AC input voltage from the output of the AC generator the inductor is first loaded by current from the output of the AC generator and then discharged into the storage capacitor. An energy harvesting system which uses an AC generator for generating electrical energy out of mechanical energy, a rectifier circuit which is connected with the input to the output of the AC generator and a low power wireless system as application unit. A method of rectifying an AC output voltage of an AC generator for use in an energy harvesting application. ## Claims ### Claim 1 A rectifier circuit for use in an energy harvesting application in which mechanical energy is converted into electrical energy using an AC generator, comprising: an active rectifier bridge with a pair of input terminals adapted to be connected to an output of the AC generator and a pair of output terminals; an inductor connected across the output terminals of the active rectifier bridge; a storage capacitor; a pair of output switches selectively connecting the storage capacitor across the inductor; and a controller for controlling the active rectifier bridge and the pair of output switches such that in successive switching cycles within any half wave of AC input voltage from the output of the AC generator the inductor is first loaded by current from the output of the AC generator and then discharged into the storage capacitor. ### Claim 2 (depends on 1) The circuit of claim 1, wherein a decoupling capacitor is connected across the input terminals of the active rectifier bridge, the decoupling capacitor being smaller than the storage capacitor and adapted to average a peak current into the active rectifier bridge. ### Claim 3 (depends on 1) The circuit of claim 1, wherein the ratio of a time interval t1 during which the inductor is loaded to the duration T of a switching cycle is adjusted to match the internal impedance of the AC generator. ### Claim 4 (depends on 1) The circuit of any of claim 1, further comprising: a DC/DC converter fed from the storage capacitor and supplying an application unit. ### Claim 5 (depends on 2) The circuit of any of claim 2, further comprising: a DC/DC converter fed from the storage capacitor and supplying an application unit. ### Claim 6 (depends on 3) The circuit of any of claim 3, further comprising: a DC/DC converter fed from the storage capacitor and supplying an application unit. ### Claim 7 (depends on 1) The circuit of claim 1, wherein the controller is further adapted to control the active rectifier bridge to perform an overvoltage protection by short circuiting the AC generator when the output voltage of the AC generator or the voltage stored in the storage capacitor exceeds a maximum voltage. ### Claim 8 (depends on 1) The circuit of claim 1, further comprising a polarity detector adapted to output a polarity signal. ### Claim 9 (depends on 1) The circuit of claim 1, wherein the controller is further adapted to sense the AC generator output voltage and to start operation of the rectifier circuit when the sensed voltage is higher than a given threshold value. ### Claim 10 (depends on 1) An energy harvesting system, comprising: an AC generator for generating electrical energy out of mechanical energy; a rectifier circuit according to claim 1, connected with the input to the output of the AC generator; and a low power wireless system as application unit. ### Claim 11 (depends on 2) An energy harvesting system, comprising: an AC generator for generating electrical energy out of mechanical energy; a rectifier circuit according to claim 2, connected with the input to the output of the AC generator; and a low power wireless system as application unit. ### Claim 12 (depends on 3) An energy harvesting system, comprising: an AC generator for generating electrical energy out of mechanical energy; a rectifier circuit according to claim 3, connected with the input to the output of the AC generator; and a low power wireless system as application unit. ### Claim 13 (depends on 4) An energy harvesting system, comprising: an AC generator for generating electrical energy out of mechanical energy; a rectifier circuit according to claim 4, connected with the input to the output of the AC generator; and a low power wireless system as application unit. ### Claim 14 (depends on 5) An energy harvesting system, comprising: an AC generator for generating electrical energy out of mechanical energy; a rectifier circuit according to claim 5, connected with the input to the output of the AC generator; and a low power wireless system as application unit. ### Claim 15 (depends on 6) An energy harvesting system, comprising: an AC generator for generating electrical energy out of mechanical energy; a rectifier circuit according to claim 6, connected with the input to the output of the AC generator; and a low power wireless system as application unit. ### Claim 16 (depends on 7) An energy harvesting system, comprising: an AC generator for generating electrical energy out of mechanical energy; a rectifier circuit according to claim 7, connected with the input to the output of the AC generator; and a low power wireless system as application unit. ### Claim 17 A method of rectifying an AC output voltage of an AC generator for use in an energy harvesting application in which mechanical energy is converted into electrical energy, comprising: providing an active rectifier bridge which is connected with input terminals to an output of the AC generator and with output terminals to an inductor; and in successive switching cycles of a duration T within any half wave of the AC output voltage: loading the inductor by current from the output of the AC generator during a first time interval t1 of each switching cycle; controlling the active rectifier bridge to disconnect after the time interval t1 the inductor from the output of the AC generator and connecting the inductor to a storage capacitor; discharging during a second time interval of each switching cycle the energy stored in the inductor into the storage capacitor.