Fuse assembly using coated wound wire and sacrificial core
A fuse assembly includes a housing and a wound wire operable as a fusible element. The housing has a cavity for the fusible element. The fusible element is formed by coating a wire with enamel and wrapping the wire around a core to produce enamel-coated wound wire. The enamel-coated wound wire is attached to the housing. The core is etched away until the core is dissolved and the enamel is stripped away.
1. A method comprising:
coating a wire with enamel, wherein the wire is to be used as a fusible element of a fuse assembly;
wrapping the wire around a core, resulting in an enamel-coated wound wire;
adding an etchant to the core, causing the core to dissolve; and
stripping the enamel from the enamel-coated wound wire.
2. The method of claim 1 , further comprising:
soldering the enamel-coated wound wire to a first lead and a second lead of a fuse base.
3. The method of claim 2 , further comprising
attaching the first lead to a first end of the fuse base; and
attaching the second lead to a second end of the fuse base, wherein the first end is on an opposite side of the fuse base from the second lead.
4. The method of claim 3 , further comprising:
attaching a first joint to the first lead of the fuse base, the first joint having a first opening; and
attaching a second joint to the second lead of the fuse base, the second joint having a second opening.
5. The method of claim 4 , wherein the core is disposed through the first opening and the second opening.
6. The method of claim 4 , wherein the first joint is attached to the first lead using solder and the second joint is attached to the second lead using solder.
7. The method of claim 4 , wherein the first joint is attached to the first lead by welding and the second joint is attached to the second lead by welding.
8. The method of claim 1 , wherein the etchant used to dissolve the core does not affect the enamel.
9. The method of claim 8 , wherein the etchant is ammonia-based.
10. The method of claim 1 , wherein the stripping operation does not affect the wire.
11. The method of claim 10 , wherein the stripping operation is performed using an ink stripper.
12. The method of claim 1 , wherein the wire is a silver-plated copper nickel alloy.
13. The method of claim 12 , wherein the wire is silver-plated CuNi44.