XESS - Comments for "Thinking Too Much"

If you only want to parallel

devbisme — Thu, 29 Sep 2011 17:03:04 +0000

If you only want to parallel two resistors, then using the values 2.0, 2.7, 6.2 and 9.1 will get you within +/-6% until you get into the MOhm range. If you use the values 1.3, 3.0, 4.7, 6.2 and 8.2, then it's just a tiny bit better (+4% / -6%).

Yes, to get rid of the sign.

devbisme — Thu, 29 Sep 2011 15:25:24 +0000

Yes, to get rid of the sign. You could also use the absolute value.

Why do you square the

miki — Thu, 29 Sep 2011 08:10:08 +0000

Why do you square the percentage mismatch? just to get rid of the sign ? or?

This is a great idea...I'm

KillerBug — Thu, 29 Sep 2011 07:06:04 +0000

This is a great idea...I'm just not sure about the numbers of resistors. How many different values would be needed if I wanted a maximum of 2 stacked resistors with +-5% coverage for all the standard values?

Right now I am using 64-drawer cabinets to hold my resistors...mostly through-hole stuff. I have filled two of the cabinets...about 90 drawers are standard value +-5% resistors, while the rest are +-1% resistors in the more common values.

I want to get a good selection of 0805 and 0603 resistors, but I don't have room for another pair of cabinetts. I figure that I can easily split the drawers so that I can put 0805 and 0603 resistors of the same value into the same drawer. I have about 40 free drawers right now...could your python program be used to find me a solution?

In real-world applications

MarkF — Thu, 29 Sep 2011 04:10:19 +0000

In real-world applications this would tend to improve the overall tolerance of the final resistance values. 5% and 10% resistors, for example, are typically manufactured together and then tested to determine which tolerence band they fit into. Thus, a pack of 10% resistors won't have any resistors within 5% of the marked value. When you serialize or parallize them the tolerances either sum (i.e. stay within the tolerance range for the final value) or cancel each other out (which is better), depending on which side of the 5% exclusion band they fall into. If I were you I'd take this into account when generating your table, any time you encounter a value that can be achieved in two or more different ways then choose the combination that has resistors of most similar value to increase the chance of a tolerance match.

Doh!

devbisme — Thu, 29 Sep 2011 01:50:38 +0000

Doh!

You said, "I was making a

Anonymous — Thu, 29 Sep 2011 00:28:33 +0000

You said, "I was making a clone of my hard drive to keep at my sister's place. (I do this in case my ex-wife ever decides to come by and burn my house down.)" You nit-wit, now your ex-wife will burn down both your's and your sister's house!

How can the net amount of

Morgauxo — Wed, 28 Sep 2011 18:35:36 +0000

How can the net amount of entropy of the universe be massively decreased?

Hah! Now try un-asking that one! MultiVac couldn't even do it!

Yeah, that's the trick. You

devbisme — Wed, 28 Sep 2011 13:04:18 +0000

Yeah, that's the trick. You need to stay on your path, but still find a way to take deviations from it.

Nice analysis, even if it's

Steven — Tue, 27 Sep 2011 18:05:03 +0000

Nice analysis, even if it's not worth the effort of actually using the data :-).

I know what you mean about not being able to unask the question. I'm a very inquiry-driven person myself; the problem is aligning the questions I pursue with my larger goals...