# US 2021/0280382 A1 · High-voltage direct-current thermal fuse > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0280382 A1 - Document ID: US20210280382A1 - Status: Published application - Kind: A1 - Application number: 17/329,182 - Filed: 2021-05-25 - Published: 2021-09-09 - Earliest claimed: 2017-06-30 - Assignees: Xiamen Set Electronics Co., Ltd - Applicants: Xiamen Set Electronics Co., Ltd - Inventors: Yaoxiang HONG - Web page: https://patentgrep.com/patent/US20210280382A1 ## CPC - H01H 85/12: Two or more separate fusible members in parallel - H01H 85/08: characterised by the shape or form of the fusible member - H01H 85/143: Electrical contacts; Fastening fusible members to such contacts - H01H 85/165: Casings - H01H 85/18: Casing fillings, e.g. powder - H01H 85/38: Means for extinguishing or suppressing arc (by powder filling H01H85/18; by mechanical tension applied to fusible member H01H85/36) - H01H 85/153: Knife-blade-end contacts - H01H 85/175: characterised by the casing shape or form - H01H 2085/383: {with insulating stationary parts} - H01H: ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES (contact cables H01B7/10; electrolytic self-interrupters H01G9/18; emergency protective circuit arrangements H02H; switching by electronic means without contact-making H03K17/00) ## Abstract A high-voltage direct-current thermal fuse includes one or more fusible components each having two fusible alloy support arms, a fluxing agent, a fusing cavity, two pins, and an insulation block. Two fusible alloy support arms are arranged opposite, and the fusible component is U-shaped. The fusible component and the fluxing agent are sealed within the fusing cavity. The two pins are respectively connected to the two fusible alloy support arms. The insulation block is arranged between the two fusible alloy support arms and separates the two pins. A volume ratio of the fluxing agent to the fusing cavity is approximately 50% or less, preferably, 10%-50%. The number of the one or more fusible components is at least two, and the at least two fusible components are arranged separately. The thermal fuse can avoid the burst and quickly cut off the current, which provides effective thermal protection for a circuit. ## Claims ### Claim 1 A high-voltage direct-current thermal fuse, comprising one or more fusible components each having two fusible alloy support arms, wherein the two fusible alloy support arms are arranged opposite from each other; a fluxing agent; a fusing cavity, wherein the each fusible component and the fluxing agent are sealed within the fusing cavity; two pins, wherein the two pins are respectively connected to the two fusible alloy support arms; and an insulation block, wherein the insulation block is arranged between the two fusible alloy support arms and separates the two pins; wherein a volume ratio of the fluxing agent to the fusing cavity is approximately 50% or less. ### Claim 2 (depends on 1) The high-voltage direct-current thermal fuse according to claim 1, wherein the volume ratio of the fluxing agent to the fusing cavity is 10%-50%. ### Claim 3 (depends on 1) The high-voltage direct-current thermal fuse according to claim 1, wherein one or more fusible components are U-shaped. ### Claim 4 (depends on 1) The high-voltage direct-current thermal fuse according to claim 1, wherein a number of the one or more fusible components is at least two, and the at least two fusible components are arranged separately. ### Claim 5 (depends on 4) The high-voltage direct-current thermal fuse according to claim 4, wherein a cross-sectional area of at least one fusible component of the at least two fusible components is smaller than cross-sectional areas of other fusible components of the at least two fusible components, and an operating temperature of the at least one fusible component having a small cross-sectional area is higher than operating temperatures of the other fusible components having large cross-sectional areas. ### Claim 6 (depends on 5) The high-voltage direct-current thermal fuse according to claim 5, wherein the at least two fusible components with different cross-sectional areas have an operating temperature difference of more than or equal to 5° C. ### Claim 7 (depends on 1) The high-voltage direct-current thermal fuse according to claim 1, further comprising a housing and a bottom plate, wherein the insulation block is arranged on the bottom plate, and the housing, the bottom plate, the insulation block, and the two pins form the fusing cavity. ### Claim 8 (depends on 1) The high-voltage direct-current thermal fuse according to claim 1, wherein a fusible alloy connection segment is connected between the two fusible alloy support arms, and the two fusible alloy support arms and the fusible alloy connection segment together form the U-shaped structure. ### Claim 9 (depends on 1) The high-voltage direct-current thermal fuse according to claim 1, wherein the two pins are perpendicular to the two fusible alloy support arms. ### Claim 10 (depends on 1) The high-voltage direct-current thermal fuse according to claim 1, wherein a non-metallic partition film is arranged inside the fusing cavity to divide the fusing cavity into an inner cavity and an outer cavity, the inner cavity and the outer cavity are mutually sealed, the fluxing agent is arranged inside the inner cavity, and an arc-extinguishing medium is arranged inside the outer cavity. ### Claim 11 (depends on 10) The high-voltage direct-current thermal fuse according to claim 10, wherein the arc-extinguishing medium is quartz sand. ### Claim 12 (depends on 1) The high-voltage direct-current thermal fuse according to claim 1, wherein each of the two pins has a flat end and a wavy end, the flat end configured for external connection is away from the fusing cavity, and the wavy end is adjacent to the fusing cavity.