Does anybody know what the DIN-number in the THT resistor footprints means?

#1

The current THT resistor footprints have a din number within them. I would be interested if anybody can explain this number. (Does it relate to the resistor size or to some other detail?)

If there is a relation between this number and the size of the resistor, can you share (maybe in a pm) your source that shows it? Best would be a table that has all DIN numbers related to the resistor size. (I have a table relating the din number to power and voltage ratings. There it seems these values depend on the standard under which the resistor is manufactured.)

As an example there is the resistor DIN-0204 which current has the size L3.6 and D1.6 given in the official lib. I found other sources that give values between L4.1 to L4.6, D1.8 to D1.9 for a resistor with the same DIN number. I did not find a source that gave the measurements of the resistor currently in our library.

#2

This PDF document has some information and examples that may be of help?

Terje

#3

I think in practice the exact body size for THT resistors is a bit irrelevant, because the lead pitch does not depend so much on body size (unlike SMD), so a nominal size with a large tolerance is OK. The lead pitch is the important parameter for PCB assembly, but in production a lead forming machine is used, which can cut and bend the leads straight from a bandolier to a whole range of styles.

I scraped resistors from a vendor we site, and tried to match to KiCad footprints with a fairly fuzzy match. I did wonder if there is an official DIN list somewhere, because a lot of resistors had odd sizes which didn’t really match any of our footprints.

#4

I could dig up this table, which lists all DIN standards applicable depending on the resistor type:

Elektronik fĂĽr Ingenieure und Naturwissenschaftler, Image 2-9, page 96 (Google Books)

I also found a paragraph in this book:

Widerstände, Kondensatoren, Spulen und ihre Werkstoffe, chapter 1.11.1, page 85 (Google Books)

which explicitly states that the naming scheme for wired resistors is derived from the size and that the applicable standard is DIN 44185. Unfortunately, while i have an extensive collection of standards available, this one isn’t part of it. What’s more is that it has been withdrawn some time ago and I could not find a reference to a replacement standard.

#5

The most likely replacement standard is EN 60115-2:2015

#6

This one also isn’t included in the library that I have access to :unamused: