# US 2021/0281185 A1 · Rectifier circuit, power supply device, and rectifier circuit drive method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0281185 A1 - Document ID: US20210281185A1 - Status: Published application - Kind: A1 - Application number: 17/251,670 - Filed: 2019-05-29 - Published: 2021-09-09 - Earliest claimed: 2018-06-15 - Assignees: Sharp Kabushiki Kaisha - Applicants: Sharp Kabushiki Kaisha - Inventors: TAKESHI SHIOMI - Web page: https://patentgrep.com/patent/US20210281185A1 ## CPC - H02M 3/335: using semiconductor devices only - H02M 3/33592: {having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer} - H02M 1/0054: {Transistor switching losses (periodically suspending operation of switching converter in low power mode H02M1/0035)} - H02M 1/007: {Plural converter units in cascade (push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826)} - H02M 1/4208: {Arrangements for improving power factor of AC input} - H02M 3/158: including plural semiconductor devices as final control devices for a single load - 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 transient current in a rectifier circuit is effectively reduced. In a rectifier circuit, a first rectifier is provided between a first terminal and a second terminal. In the rectifier circuit, when a switch element is turned ON, a primary winding current flows from a power supply to a primary winding of a transformer. When the switch element is turned OFF, a second rectifier current flows from a secondary winding of the transformer to a second rectifier. During a period in which the second rectifier current is flowing, a reverse voltage is applied between the first terminal and the second terminal. ## Claims ### Claim 1 A rectifier circuit, comprising: a first terminal; and a second terminal, with reference to the first terminal, a positive voltage to be applied to the second terminal being a forward voltage, with reference to the second terminal, a positive voltage to be applied to the first terminal being a reverse voltage, if the forward voltage is applied, a forward rectifier circuit current flowing from the second terminal to the first terminal, and if the reverse voltage is applied, the forward rectifier circuit current being blocked, the rectifier circuit, further comprising: a first rectifier connected to the first terminal and the second terminal; a transformer including a primary winding and a secondary winding; a second rectifier connected in parallel to the first rectifier through the secondary winding; a switch element connected to the primary winding; and a power supply connected to the primary winding, when the switch element is turned ON, a primary winding current flowing from the power supply to the primary winding, when the switch element is turned OFF, a second rectifier current flowing from the secondary winding to the second rectifier, and during a period in which the second rectifier current is flowing, the reverse voltage being applied. ### Claim 2 (depends on 1) The rectifier circuit according to claim 1, wherein the period in which the second rectifier current is flowing is as long as, or shorter than, half of a period in which the primary winding current flows. ### Claim 3 (depends on 1) The rectifier circuit according to claim 1, wherein during a period in which the forward rectifier circuit current is flowing in the first rectifier, the second rectifier current starts to flow. ### Claim 4 (depends on 1) The rectifier circuit according to claim 1, further comprising a specific path from the first terminal through the first rectifier to the second terminal, wherein the secondary winding has an inductance twice as high as, or higher than, an inductance of the specific path. ### Claim 5 (depends on 1) The rectifier circuit according to claim 1, wherein the primary winding is formed into more turns than the secondary winding is. ### Claim 6 (depends on 1) A power supply device comprising the rectifier circuit according to claim 1. ### Claim 7 A rectifier circuit drive method for driving a rectifier circuit, the rectifier circuit including: a first terminal; and a second terminal, in the rectifier circuit, with reference to the first terminal, a positive voltage to be applied to the second terminal being a forward voltage, with reference to the second terminal, a positive voltage to be applied to the first terminal being a reverse voltage, if the forward voltage is applied, a forward rectifier circuit current flowing from the second terminal to the first terminal, and if the reverse voltage is applied, the forward rectifier circuit current being blocked, the rectifier circuit further including: a first rectifier connected to the first terminal and the second terminal; a transformer including a primary winding and a secondary winding; a second rectifier connected in parallel to the first rectifier through the secondary winding; a switch element connected to the primary winding; and a power supply connected to the primary winding, the rectifier circuit drive method, comprising: applying the forward voltage, so that the forward rectifier circuit current flows; turning the switch element ON after the applying the forward voltage, so that a primary winding current flows from the power supply to the primary winding; turning the switch element OFF after the turning the switch element ON, so that a second rectifier current flows from the secondary winding to the second rectifier, and applying the reverse voltage, after the turning the switch element OFF, during a period in which the second rectifier current is flowing. ### Claim 8 (depends on 2) The rectifier circuit according to claim 2, wherein during a period in which the forward rectifier circuit current is flowing in the first rectifier, the second rectifier current starts to flow. ### Claim 9 (depends on 2) The rectifier circuit according to claim 2, further comprising a specific path from the first terminal through the first rectifier to the second terminal, wherein the secondary winding has an inductance twice as high as, or higher than, an inductance of the specific path. ### Claim 10 (depends on 3) The rectifier circuit according to claim 3, further comprising a specific path from the first terminal through the first rectifier to the second terminal, wherein the secondary winding has an inductance twice as high as, or higher than, an inductance of the specific path. ### Claim 11 (depends on 8) The rectifier circuit according to claim 8, further comprising a specific path from the first terminal through the first rectifier to the second terminal, wherein the secondary winding has an inductance twice as high as, or higher than, an inductance of the specific path. ### Claim 12 (depends on 2) The rectifier circuit according to claim 2, wherein the primary winding is formed into more turns than the secondary winding is. ### Claim 13 (depends on 3) The rectifier circuit according to claim 3, wherein the primary winding is formed into more turns than the secondary winding is. ### Claim 14 (depends on 4) The rectifier circuit according to claim 4, wherein the primary winding is formed into more turns than the secondary winding is. ### Claim 15 (depends on 8) The rectifier circuit according to claim 8, wherein the primary winding is formed into more turns than the secondary winding is. ### Claim 16 (depends on 9) The rectifier circuit according to claim 9, wherein the primary winding is formed into more turns than the secondary winding is. ### Claim 17 (depends on 10) The rectifier circuit according to claim 10, wherein the primary winding is formed into more turns than the secondary winding is. ### Claim 18 (depends on 11) The rectifier circuit according to claim 11, wherein the primary winding is formed into more turns than the secondary winding is.