Remote activated fuse and circuit

• US 9,887,057 B2
• Filed: 11/20/2012
• Issued: 02/06/2018
• Est. Priority Date: 11/20/2012
• Status: Active Grant

• Current Assignee: Littelfuse Incorporated
• Original Assignee: Littelfuse Incorporated
• Inventors: Lam, Johnny, Matthiesen, Martyn A., Galla, Matthew P., Chen, Jianhua
• Primary Examiner(s): Gandhi, Jayprakash N
• Assistant Examiner(s): CRUM, JACOB R
• Application Number:
  US13/682,270
• Publication Number:
  US 20140139314A1
• Time in Patent Office: 1,904 Days
• Field of Search: 337159, 337401
• CPC Class Codes: H01H 2085/0275 Structural association with a printed circuit board
• CPC Class Codes: H01H 2085/466 with remote controlled forced fusing
• CPC Class Codes: H01H 37/76 Contact member actuated by melting of fusible material, actuated due to burning of combustible material or due to explosion of explosive material
• CPC Class Codes: H01H 37/761 with a fusible element forming part of the switched circuit H01H37/767 takes precedence
• CPC Class Codes: H01H 85/463 with printed circuit fuse

Abstract

A fuse includes first, second, and third terminals disposed on a substrate. Respective ends of one or more primary conductors of the fuse are connected to one of the first and the second terminals. The primary conductors have a first conductivity and are configured to open when a primary current between the first and the second terminals exceeds a first predetermined threshold. One or more secondary conductors have an end connected to the third terminal. The secondary conductors are configured to ignite when a secondary current through the secondary conductors exceeds a second predetermined threshold. When ignited, the secondary conductors open the primary conductors to thereby stop the primary current.

Claims

1. A fuse comprising:

first, second, and third terminals disposed on a substrate;

one or more primary conductors with respective ends connected to one of the first and the second terminals, wherein each of the one or more primary conductors has a first conductivity and opens when a primary current between the first and the second terminals exceeds a first pre-determined threshold; and

one or more secondary conductors in direct contact with, and interwoven with, the one or more primary conductors with first ends connected to the third terminal, at least one of the one or more secondary conductors to ignite via a secondary current flowing through the at least one of the one or more secondary conductors that exceeds a second predetermined threshold,

wherein ignition of the at least one of the one or more secondary conductor opens the one or more primary conductors to thereby stop the primary current.

2. The fuse according to claim 1, wherein the secondary current flows between the first terminal and third terminal.

3. The fuse according to claim 1, wherein at least a portion of the one or more secondary conductors is separated from the substrate by an insulator.

4. The fuse according to claim 1, further comprising an electrode and a bridge connector, wherein second ends of the one or more secondary conductors are connected to the electrode, and wherein at least one of the first terminal and the second terminal are connected to the bridge connector.

5. The fuse according to claim 1, wherein the one or more secondary conductors comprises exothermic reactive material.

11. The fuse according to claim 1, the one or more secondary conductors to ignite via an exothermic reaction that exhausts at least a portion of the one or more secondary conductors.

6. A fuse protected circuit comprising:

a fuse housing that comprises;

first, second, and third terminals disposed on an outside surface of the housing, wherein the first and second terminals are in series with a circuit to be protected;

a substrate, wherein at least a portion of each of the first, second, and third terminals is also disposed on the substrate;

one or more primary conductors with respective ends connected to one of the first and the second terminals, wherein the one or more primary conductors has a first conductivity and opens when a primary current between the first and the second terminals exceeds a first predetermined threshold; and

one or more secondary conductors in direct contact with, and interwoven with, the one or more primary conductors with respective first ends connected to the third terminal, at least one of the one or more secondary conductors to ignite via a secondary current flowing through at least one of the one or more secondary conductors that exceeds a second predetermined threshold, wherein ignition of the at least one of the one or more secondary conductors opens the primary conductors to thereby stop the primary current; and

a component with a first end in electrical communication with the third terminal and a second end at a voltage potential that is different than the first terminal, wherein the component facilitates current flow between the first terminal and the third terminal upon activation of the component, to thereby cause the secondary conductors to ignite and the primary conductors to open.

7. The fuse protected circuit according to claim 6, wherein the component corresponds to an anomalous negative-temperature-coefficient device or a linear NTC device with a resistance that decreases as a temperature of the NTC device increases.

8. The fuse according to claim 6, wherein the secondary current flows between the first terminal and third terminal.

9. The fuse according to claim 6, further comprising an electrode and a bridge connector, wherein a respective second end of the one or more secondary conductors is connected to the electrode, and wherein at least one of the first terminal and the second terminal are connected to the bridge connector.

10. The fuse according to claim 6, wherein the one or more secondary conductors comprise exothermic reactive material.

12. The fuse according to claim 6, the one or more secondary conductors to ignite via an exothermic reaction that exhausts at least a portion of the one or more secondary conductors.