I did NOT suggest putting time on a linear scale, just a useful one. The BS1361 fuses have a particularly wide range Graham, because they are not really there for overload protection, just short circuit protection (or severe fault). Because of the range, one can see why this might be.
Graphs with straight lines or proper accurate equations and matching scaling are more useful. Looking at fuses, the adiabatic current ratings of fuses are set by the physics Mike outlined. They should not have huge ranges, just reasonable manufacturing tolerances. If one wishes to see the entire envelope, fair enough, but we wish in most cases to examine the worst-case time/current value. Quicker fusing is not a problem for faults to overloads, it is the longest time that is dangerous. Next time I have a spare few minutes I will attempt to produce an equation and axis scaling which produces straight lines.
Geoff, you do have an error but it is interesting (I2 - I1) / (I2 - I1) always equals 1! I think you were attempting linear interpolation, between 2 points, but this is not it. I will leave the correct answer to the student!
I did NOT suggest putting time on a linear scale, just a useful one. The BS1361 fuses have a particularly wide range Graham, because they are not really there for overload protection, just short circuit protection (or severe fault). Because of the range, one can see why this might be.
Graphs with straight lines or proper accurate equations and matching scaling are more useful. Looking at fuses, the adiabatic current ratings of fuses are set by the physics Mike outlined. They should not have huge ranges, just reasonable manufacturing tolerances. If one wishes to see the entire envelope, fair enough, but we wish in most cases to examine the worst-case time/current value. Quicker fusing is not a problem for faults to overloads, it is the longest time that is dangerous. Next time I have a spare few minutes I will attempt to produce an equation and axis scaling which produces straight lines.
Geoff, you do have an error but it is interesting (I2 - I1) / (I2 - I1) always equals 1! I think you were attempting linear interpolation, between 2 points, but this is not it. I will leave the correct answer to the student!
