# US 2019/0173385 A1 · Dc-dc converter > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2019/0173385 A1 - Document ID: US20190173385A1 - Status: Published application - Kind: A1 - Application number: 16/191,568 - Filed: 2018-11-15 - Published: 2019-06-06 - Earliest claimed: 2017-12-01 - Assignees: Korea Aerospace Research Institute - Applicants: Korea Aerospace Research Institute - Inventors: Jeong Eon Park; Nayoung Lee; Jae-dong Choi; Jin Baek Jang; Sang-ryool Lee - Web page: https://patentgrep.com/patent/US20190173385A1 ## CPC - H02M 3/1584: {with a plurality of power processing stages connected in parallel} - H02M 1/14: Arrangements for reducing ripples from DC input or output - H02M 1/15: using active elements - H02M 1/0064: {Magnetic structures combining different functions, e.g. storage, filtering or transformation} - H02M 3/125: using devices of a thyratron or thyristor type requiring extinguishing means - 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) ## Abstract A DC-DC converter includes a first transformer connected between a first node and a ground, the first node being located between an input terminal and an output terminal, and the first transformer comprising a first inductor and a second inductor magnetically coupled to each other, a first switch serially connected to the first inductor, between the first node and the ground, a second switch serially connected to the second inductor, between the first node and the ground, a third switch connected between a second node and the output terminal, the second node being located between the second inductor and the second switch, and a fourth switch connected between a third node and the output terminal, the third node being located between the first inductor and the first switch, and the third and fourth switch being controlled in a same manner as the first and second switch, respectively. ## Claims ### Claim 1 A DC-DC converter comprising: a first transformer connected between a first node and a ground, the first node being located between an input terminal and an output terminal, and the first transformer comprising a first inductor and a second inductor magnetically coupled to each other; a first switch serially connected to the first inductor, between the first node and the ground; a second switch serially connected to the second inductor, between the first node and the ground; a third switch connected between a second node and the output terminal, the second node being located between the second inductor and the second switch, and the third switch being controlled in a same manner as the first switch; and a fourth switch connected between a third node and the output terminal, the third node being located between the first inductor and the first switch, and the fourth switch being controlled in a same manner as the second switch. ### Claim 2 (depends on 1) The DC-DC converter of claim 1, further comprising: a second transformer connected between the input terminal and the output terminal and comprising a third inductor and a fourth inductor magnetically coupled to each other; and a diode having an anode connected to the fourth inductor and a cathode connected to the output terminal. ### Claim 3 (depends on 2) The DC-DC converter of claim 2, wherein the third inductor is connected between the input terminal and the first node, and the fourth inductor is connected between the first node and the diode. ### Claim 4 (depends on 2) The DC-DC converter of claim 2, wherein, when both of the first switch and the second switch are turned off, an output current flows through the diode. ### Claim 5 (depends on 1) The DC-DC converter of claim 1, wherein the first switch and the second switch are alternately turned on, and when the first switch is turned on, the second switch is turned off, and when the second switch is turned on, the first switch is turned off. ### Claim 6 (depends on 1) The DC-DC converter of claim 1, wherein the first switch and the second switch are turned on at a same duty ratio, and the duty ratio is less than about 50%. ### Claim 7 (depends on 1) The DC-DC converter of claim 1, wherein a current flows from the second node to the output terminal only when the third switch is turned on, and a current flows from the third node to the output terminal only when the fourth switch is turned on. ### Claim 8 (depends on 1) The DC-DC converter of claim 1, wherein the third switch is a first thyristor having an anode connected to the second node and a cathode connected to the output terminal, and the fourth switch is a second thyristor having an anode connected to the third node and a cathode connected to the output terminal. ### Claim 9 (depends on 8) The DC-DC converter of claim 8, further comprising a controller outputting a first control signal to control the first thyristor and outputting a second control signal to control the second thyristor. ### Claim 10 (depends on 9) The DC-DC converter of claim 9, wherein the first thyristor and the second switch are controlled by the first control signal, and the second thyristor and the first switch are controlled by the second control signal. ### Claim 11 (depends on 1) The DC-DC converter of claim 1, wherein, when the first switch is turned on, an induced current generated in the second inductor due to a current flowing into the first inductor flows toward the output terminal via the third switch, and when the second switch is turned on, an induced current generated in the first inductor due to a current flowing into the second inductor flows toward the output terminal via the fourth switch. ### Claim 12 (depends on 1) The DC-DC converter of claim 1, wherein the third switch is configured to be turned on when the first switch is turned on, and turned off when the first switch is turned off, and the fourth switch is configured to be turned on when the second switch is turned on, and turned off when the second switch is turned off.