That's the formula I used for calculating all E series above. There are two mismatches for E96.This formula supposedly properly calculates all 1% resistor values.
Why is 21.5 in red?
That is not a mismatch as it's a standard 1% value.
Not a EE but a die maker/machinist. But the way I was taught to round up machining dimensions, the 9.19478686 would be rounded up to 9.20. In machining dimensions you go back a few places, so 9.19478686 the ''78686" would cause the "4" to be a "5", and then the "5" would cause the "19" to become a "20". Guess I don't understand why it would be different in the EE world. Or maybe I was taught wrong?There is in fact an error in the E192 series. Using the formula 10^(185/192) we get an exact value of 9.19478686. This should become a 3 digit value of 9.19, but the value found in a table of commercially available E192 resistors is 9.20
Somebody made a slide rule error way back then.
It's an EE thing.Guess I don't understand why it would be different in the EE world.
I guess. This whole wide tolerance of values thing EE is still hard for me to get over. Metal isn't so forgiving, you can't force a 20% oversize part into most things, even with a big hammer.It's an EE thing.
For E192, E96, and E48 we use 3 digits and a multiplier. For lower precision resistors, we use 2 digits and a multiplier.
Not a EE but a die maker/machinist. But the way I was taught to round up machining dimensions, the 9.19478686 would be rounded up to 9.20. In machining dimensions you go back a few places, so 9.19478686 the ''78686" would cause the "4" to be a "5", and then the "5" would cause the "19" to become a "20". Guess I don't understand why it would be different in the EE world. Or maybe I was taught wrong?
I would imagine that in mechanical assemblies it would be common to decide whether a given dimension should be rounded up or rounded down based on the particular goal and I would expect those considerations to require dimensions be rounded up most of the time. If you are designing a shear pin to have a safety factor of two and the needed diameter comes out to be 9.014 inches and your final part dimension is to be dimensioned to a tenth of an inch, then you would dimension it as 9.1 inches because 9.0 inches doesn't have the required safety factor. The same thing CAN happen in circuit design, but the natural tolerances of the parts generally swamps this so that, when needed, you use a larger margin and then round normally. It's also usually very application specific whether a value should be rounded up or rounded down to achieve a particular constraint, so having the component standards adopt one or the other makes little sense.Not a EE but a die maker/machinist. But the way I was taught to round up machining dimensions, the 9.19478686 would be rounded up to 9.20.
That really doesn't make any sense. Which value is closer to 9.19478686, 9.19 or 9.20? If your intent is to choose the dimension that is closest to the ideal one, then you would choose 9.19.In machining dimensions you go back a few places, so 9.19478686 the ''78686" would cause the "4" to be a "5", and then the "5" would cause the "19" to become a "20". Guess I don't understand why it would be different in the EE world. Or maybe I was taught wrong?
No because the number of "4's" in that number don't approach the higher numbers in the original example. It's not a statisical thing at all. But you guy's also come from a different back round than I do.According to your approach, you would round 9.19444445 upward.
Where's any statistics?No because the number of "4's" in that number don't approach the higher numbers in the original example. It's not a statisical thing at all. But you guy's also come from a different back round than I do.
We use the same rules for rounding that other disciplines use.But you guy's also come from a different back round than I do.
Not a EE but a die maker/machinist. But the way I was taught to round up machining dimensions, the 9.19478686 would be rounded up to 9.20. In machining dimensions you go back a few places, so 9.19478686 the ''78686" would cause the "4" to be a "5", and then the "5" would cause the "19" to become a "20". Guess I don't understand why it would be different in the EE world. Or maybe I was taught wrong?
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