- #1
tempneff
- 85
- 3
Hi all,
I am trying to get an understanding of Onderdonk's Fuse Equation:
##I_{fuse}=Area*\frac{\sqrt{log\left(\frac{T_{melt-T_{ambient}}}{234-T_{ambient}}+1\right)}}{33*Time}##
Empirically I do not see that this function accurately depicts the behavior of the wires I am using. For example, I hooked up a 37 gauge copper wire to a current source with 3A. I verified the values in this chart of Onderdonk's values for copper against the equation and found that they agree. I should have seen the wire break within a second, however it glowed but did not break. It took nearly 5A to melt it.
I'd like to know what assumptions were made for this equation to work? Such as length of wire, ambient pressure maybe...
Thanks in advance, I love this site.
I am trying to get an understanding of Onderdonk's Fuse Equation:
##I_{fuse}=Area*\frac{\sqrt{log\left(\frac{T_{melt-T_{ambient}}}{234-T_{ambient}}+1\right)}}{33*Time}##
Empirically I do not see that this function accurately depicts the behavior of the wires I am using. For example, I hooked up a 37 gauge copper wire to a current source with 3A. I verified the values in this chart of Onderdonk's values for copper against the equation and found that they agree. I should have seen the wire break within a second, however it glowed but did not break. It took nearly 5A to melt it.
I'd like to know what assumptions were made for this equation to work? Such as length of wire, ambient pressure maybe...
Thanks in advance, I love this site.