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Thread: Fuse curves

  1. #1
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    Fuse curves

    OK, understand I squared t, melting, etc, and that at microsecond times fuses break vs melt.

    Looking at some snad filled type fuse curves (e.g littelfuse L50S), there is a slope to the curve in the sub-millisecond region indicative of a cube function of current.

    Why cube? -- or is that just a coincidence transitioning from melting to breaking?

  2. #2
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    how did you determine this?
    time = k x 1/i^3 ???

    <0.001 sec???

  3. #3
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    just drew a straight line along the logarithmic fuse curve at times < 1 ms. Slope is 10x times = 1000 X current on the fuse curve.

  4. #4
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    not sure that is valid
    10 A fuse

    time(sec)...i(A)
    100.......28
    1..........40
    0.006....60

    slope = (100-0.006)/(28-60)=-3.12 sec/A
    slope = (100-1)/(28-40)= -8.52 sec/A
    slope = (1-0.006)/(40-60)=-0.05 sec/A

    not linear

    guessing of the form time = k x e^-(i - i100)
    i100 = i at 100 sec
    don't feel like messing with the math

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