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Not too long ago in Boston, Ladyada, Amanda (w0z) and Phil met Stephen Wolfram, they talked about adding features for electrical engineers, as they chatted Stephen typed in notes directly to the “feature request” on his iPad – today we received this email!
Dear Limor Fried,
…you gave us some suggestions for features in Wolfram|Alpha. I thought you might like to see that we finally implemented something in regard to resistance.
http://www.wolframalpha.com/input/?i=456+ohms
http://www.wolframalpha.com/input/?i=14+kiloohms
Cool!
FEED
That’s cool.
I’m not sure about the usefulness of the function that displays networks of common resistor values closest to the value entered, though.
That’s because you can’t expect to consistently get within, say, 0.14% of the value entered (as for the 14 kiloohm link above) using 10% tolerance resistors.
The resistor network function could be improved by allowing selection of the tolerance of the resistors available (and not just the range of values to select from, E6 or E12) and using that information to calculate the tolerance for the whole network.
When moving from prototype to production, chaining multiple component errors or tolerances in this way is more likely to affect circuit yield than designing with a single component of a precisely known value that is slightly off from the target value.5
Comment by Dave — July 7, 2011 @ 3:58 am