Fusible link
First Claim
1. An electrical circuit having a fusible link, the fusible link formed at an aperture through a printed circuit board, the link being a length of fusible alloy having a close fit within said aperture wherein one end of said fusible alloy length is electrically connected to a circuit lead on one side of the board and the other end of said length is electrically connected to a circuit lead on the opposite side of the board, and a resistive film located adjacent said link and, together with said link and said circuit leads, being connected into said circuit, said resistive film adapted to heat the fusible alloy to its melting point when the circuit is subjected to an overvoltage condition.
3 Assignments
0 Petitions
Accused Products
Abstract
A fusible link for an electrical circuit consists of a length of fusible material which closely fits an aperture through a ceramic printed circuit board. Ends of the fusible element electrically contact respective electrical leads on opposed surfaces of the board. A resistive film forming part of the electrical circuit is located close to the fusible link site so that when overvoltage conditions exist the resistive film heats the circuit board until eventually the fusible material melts, flows out of the aperture and the electrical circuit is broken. The fusible link is soldered and/or swaged into position and projects beyond the surface of the circuit board so that when the solder melts, surface tension forces tend to pull the solder out of the aperture.
84 Citations
8 Claims
- 1. An electrical circuit having a fusible link, the fusible link formed at an aperture through a printed circuit board, the link being a length of fusible alloy having a close fit within said aperture wherein one end of said fusible alloy length is electrically connected to a circuit lead on one side of the board and the other end of said length is electrically connected to a circuit lead on the opposite side of the board, and a resistive film located adjacent said link and, together with said link and said circuit leads, being connected into said circuit, said resistive film adapted to heat the fusible alloy to its melting point when the circuit is subjected to an overvoltage condition.
Specification