Resistor & Capacitor Values; Engineering Notation

It’s not just old eyes. Colour bands fade and some are hard to distinguish when faded, e.g. red/brown, yellow/orange. I measure anyway to be sure. Also even axial resistors are tiny these days. I had need of 10M ones for crystal oscillators and bought a bandolier. Body length perhaps 5mm. I would need a powerful magnifying glass to read the bands. Fortunately I just pull one off the bandolier when I need one.

I have real trouble reading long strings of "0"s, so I don’t like to see 10000pF or 0.001uF

The Greek characters are particularly dangerous when you send a document abroad.
Be careful of mille and Mega, For example, LTSpice treats “M” as mille.

I still take photos of schematics and even off screen, so the vanishing decimal point still exists.
Add European use of comma vs period as the decimal point to the confusion.

I had to google the word "bandolier, and that looked wrong so then I tried “resistor bandolier”. I think you mean that you bought a batch of them on tape. The company I worked for in the 1990s scrapped out a bunch of excess inventory, and the local surplus component dealer did not pay enough for the gasoline to drive them out there. So I have some moderately large quantities (partial reels) of some resistors. In some cases the glue failed with age and the resistors all fell off the tape. Imagine a large plastic bag with 1000 axial resistors all tossed in with random alignment.

I agree. But I remember seeing notations all over the map, including μμF. I do not know why nF were sort of late to appear in the USA. I would think that engineering notation (such as 33e-9) would work well for you. Few zeroes and less frequent need for decimal points. Can any method completely avoid decimal points?

And yes my Dad used to think of M as meaning thousand. I guess that is from Roman numerals. If I am wrong on this, I think someone will correct me!

I didn’t make up the term. E.g.:

https://www.oritech.com.au/county-component-counter.html

The problem with tape is that it can be confused with SMD tape reels. Bandolier is much more colourful, don’t you think? Why overload terms when there are far more apt ones? :grinning:

Sounds like an Italian street musician.

Or a spaghetti western.

La schema é mobile!

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The Pico Farad pF was also late, I remember seeing μμF in 1950s schematics.
Somebody must have had a special drawing stencil. I remember printing the Greek mu micro symbol was a pain, so pF and nF became standard

Bandolier sounds elegant enough for a mundane bunch of resistors, but I prefer the much tastier version; the " pièce de ré·sis·tance "

Or…perhaps I don’t give a crap about the color codes and just use what works instead of fiddling about squinting at color bands like a dope. Seriously though I don’t understand why you feel like you need to read anything into it.

Like was recently mentioned on hackaday the color bands aren’t even the first system for color coding resistors but a later system designed for mechanical manufacturing. The old body/band/dot system was pretty easy to read by comparison… whereas the color bands are more of an after thought and often on modern resistrs they are painted wet so the colors end up mixing into a mess.

The worst but literal interpretation of your comment is that you ignore the marking and connect the resistor into the circuit to see if it works. Such method is prone to producing smoke and I suspect that is not what you intended…

Just be sure to properly document the results of the test . . . . including the COLOR of the smoke! :laughing:

Dale

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When I started work 41 years ago,in a team of five, I was the only one with normal colour vision, so I was the official resistor reader.
Even then telling yellow/orange/brown apart was a common problem due to poor ink quality

That’s easy. The color will be “Magic”. :rofl:

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:smile: That could be taken as needing more women in the workforce (I think women are less likely to be color blind) or else these days someone could make a smartphone app to read color bands. But if banded resistors were state of the art, your smartphone would be the size of a 500 square meter house.

Women very rarely get the common red-green defect as that would require 2 bad X chromosomes.
Some women have a fourth colour receptor, seeing colour differences that no man can.

Here are a few rules of SI nomenclature, which all of you should know, especially those of you outside of the United States:
• In the SI (System International, the Modern Metric System) the letters used for prefixes and base units are considered letter symbols and are NOT abbreviations.
• Upper case “K” is for kelvin temperature whereas lower case “k” is for kilo prefix.
• There is ALWAYS a space between the value (the number) and the following letter symbol(s), this includes temperature in degree Celsius (°C).
• There is always a space after the base unit when adding modifiers, that is it is “5 V dc” not “5VDC”.

Some references are IEC 80000-1; ANSI/IEEE/ASTM SI 10; and my favorite, because it is a no charge (as in free) .pdf download is NIST Special Publication 811 that is available at <www.nist.gov>.

Numbers should be between 1 and 999.+, because if the number is 1000 you would use the next higher prefix. I use the latest version of KiCad (5.whatever) on my Ubuntu OS and it recognizes UTF-8 coding, which you can do a search for on the internet. So, for a 1 kΩ resistor or a 10 µF capacitor that is the way I show them on the schematic and that is the way the values will be presented when doing a parts list (BOM) derived from the schematic diagram.
–Larry

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That implies that we Americans are dummies. Given world events, I cannot argue otherwise.

This is good stuff, and I guess you or most others can learn to follow it rigorously. However I think it is a bit difficult to keep in mind, and trying to get others to follow it sounds like herding cats. But even if you do succeed at that, some programming is probably needed to get a good spreadsheet sort.

As a second choice to exponential notation, I do like using the unit or multiplier letter in place of the decimal, such as 5V0 or 6K2. But this scheme will not sort nicely either.

One thing about scientific notation is that typos cause a noticeable error when I sort in a spreadsheet. This prompts me to go back to fix it right away.

This is a wonderfully (unintentionally, I think) ambivalent sentence. It could be interpreted as:

  1. People outside the US already know SI well, or

  2. People outside the US ought to learn SI better.

A bit like that mythical reference letter that read: You will be lucky to get so and so to work for you. :stuck_out_tongue_winking_eye:

I guess I take “know” to mean “know” and “learn” to mean “learn” so I do not see that one as ambiguous. But perhaps the loaded word is “should”. It could mean that it behooves you to know, or it could mean that you are more likely to know it due to something like exposure.

People in small boats should wear life vests versus
People who ride New York subways should be familiar with noisy train rides.

I agree. On this one, I am more inclined (72 degrees) to see at least 2 interpretations.

Yes, the should is problematic. The root cause is trying to make one sentence carry too much.