Talk:Resistor

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[edit] general

I've just found something realy interesting (at least for me). Did you ever see 0 Ω resistor? I just found it few days ago and cant figure out what is it's purpouse. Can someone maybe tell me what could be it's use? (the instrument is showing around 0,2 Ω but it is resistance from the instrument alone...) If someone does not trust me - he can see the pictures that I just took.

Image:0-ohm.jpg

and

Image:0-res---messure.jpg

Yes, "Zero-ohms" are nothing magical and therefor do have a small resistance. They are used to connect two parts of a pathway on a printed circuit-board, when one pathway for some reason had to be cut in two (e.g. becuase of another pathway crossing it's way). As they are "like" a normal resistor, they can be inserted by the same machines used to insert, cut and solder a normal resistor. You could just as easely used a thin (isolated, if board had paths on both sides) piece of wire to connect the two halfs, but then you'd probably have to insert it manually... besides, the zero-ohms looks good. Koppe

Well, yes, zero ohm resistors can be used as wire bridges in very low-tech printed circuit boards. But, a more common use these days is in the selection of "build options". For example, a manufacturer of LCD modules might offer a variant with an on-board generator for the bias voltage and a variant where the bias voltage must be supplied externally. Rather than buying and stocking different printed circuit boards for these two variants, he will typically use one that can be built two ways. On one, the on-board bias generator parts would be populated. On the other, they would be omitted and the bias line would be connected to an external connection by a zero ohm resistor.--GrahamDavies 18:41, 11 September 2007 (UTC)

What about a section about 'Contact Resistance'?

There needs to be something on star and delta resistor configurations, or is it elseware

It's at Y-delta transform — Omegatron 03:35, 10 October 2005 (UTC)

I think that a color code for resistors should be included and not linked to.

"Resistance is proportional to cross-sectional area and to the material's resistivity, a physical property of the molecules that comprise the resistor. Resistance is inversely proportional to the length of the resistor."

Shouldn't it rather be:

"Resistance is inversely proportional to cross-sectional area and proportional to the material's resistivity, a physical property of the molecules that comprise[?] the resistor. Resistance is proportional to the length of the resistor."?

S.

Yes, it should. If you find such errors again, Be bold in updating pages! Andre Engels

the resistance between the wiper and one end terminal is proportional to the logarithm of the distance between them.

probably the distance is the logarithm of the resistance! Patrick 11:23 Oct 29, 2002 (UTC)

"There is even a system that uses a photoelectric sensor "reading" the optical density of a piece of film. Since the sensor does not touch the film, no wear is possible."

so in other words, it's not a resistor, and shouldnt be in this article listed as one. right? Omegatron 20:28, Feb 26, 2004 (UTC)

why is \mathbf added to the lower resistor calculation? It makes the two look different, as the first R in the bottom is no longer italic (and the equation is uglier). Aren't the PNGs the same for every browser? I don't see how this could look consistent to one person and not consistent to me... - Omegatron

The R should have been bolded for both of them as Req stands for "equivilent resistance". Perl 22:25, 9 Mar 2004 (UTC)

I'm relatively new to electronics (and to editing wikipedia). I came to this page looking for help on understanding the color code system for indicating resistor values. I found the section here on that topic a little vague. From reading it, I don't know in what direction I'm supposed to read the bands, and I can't quite picture how the whole system would work. I think an example or two (along the lines of what's on this page) would have been helpful (especially if some actual photographic examples were included.

Thanks!

--atduskgreg

-- The gold silver etc is the last band the "normal" colours are first. wolfmankurd

--- I think the article can use more technical info relative to high frequency and power/surge overload performance. In addition, should include more regarding Mil-specs, EIA stds, resistor networks, and a brief listing of major mfrs. I added in a couple of popular mil-specs but didn't want to invest much time w/o first getting a general consensus. AerospaceEngr 21:21, 28 August 2007 (UTC)

[edit] cross sectional area and resistance

removed for verification:

(Additional note: There are two reasons why a small cross-section area tends to raise resistance. One is that the electrons, all having the same negative charge, repel each other. Thus there is resistance to many being forced into a small space. The other reason is that the electrons collide with each other, causing "scattering," and therefore they are diverted from their original directions. More discussion is on page 27 of "Industrial Electronics," by D. J. Shanefield, Noyes Publications, Boston, 2001.)

I am not sure the repelling of electrons has anything to do with resistance, though I could be wrong. Wouldn't that affect thing like superconductors, though? Similarly, electron "collisions" wouldn't seem to affect anything, since electron motion is pretty much random, and only the net flow of electrons or the electric field wave is really important... - Omegatron 16:46, Dec 9, 2004 (UTC)

[edit] what should be fixed

I know nothing about resistors. I was trying to learn. YOU DO NOT SAY WHAT A RESISTOR ACTUALLY CAN BE USED FOR! you say what it does, but not why that is useful at all. thanks!

Resistors are used for a LOT of things. Pretty much every electrical circuit uses resistors for one purpose or another. The simplest application I can think of would be something like a light dimmer. If you put a high-power resistor in series with a light bulb, you can dim the light bulb, because the resistor converts some of the electrical power into heat, leaving less power for the light bulb. Help at all? - Omegatron 20:01, Feb 10, 2005 (UTC)
The article is a bit low on info about both uses and different manufacturing techniques (carbon composite, metal film etc), I'll add a bit more info on this in within a few days. GalFisk 09:00, 30 August 2005 (UTC)


I agree with the above, I think someone who didn't know anything about what a resistor was would be very confused trying to learn it from this article. After the first paragraph, it goes right to "identifying resistors". I think it would be better to show something like an example of a simple circuit with voltages labled at different points, and maybe some simple explanation of why resistors are useful in the real world. Also, it seems like the Ohm's law reference in the first sentence, arranged to start with "R =", kind of makes it seem like the resistance of a resistor is determined by the voltage and current, and maybe that the device is "magically" constructed to follow that law. Since the sentence reads "by producing a voltage drop" maybe the equation should just be written as "V = IR" 71.233.240.242 (talk) 16:17, 30 January 2008 (UTC)

[edit] Mnemonics on remembering resistor color codes

  • At least one of these should be put on the page. There are many, but the standard I have seen in many places is:
    • Bad Boys Ravish Our Young Girls But Violet Gives Willingly

--cinderblock 00:00, 12 July 2006 (UTC)

  • Others of course also exist:
    • Bad Beer Rots Our Young Guts But Vodka Goes Well. Get Some Now!
    • B.B. ROY of Great Britain had a Very Good Wife
    • Buffalo Bill Roamed Over Yellow Grass Because Vistas Grand Were God's Sanctuary

Black Brown Red Orange Yellow Green Blue Violet Gray White (Gold Silver)

--195.225.129.1 18:07, 28 Feb 2005 (UTC)

I find that some of the mnemonics are not appropriate. Such as "Black Boys Rape our Young Girls ...". People may use this to remember the colours, but the wiki should not promote and encourage the use of these menonics. They should be removed.

--AndreJGlauser 07:48, 31 December 2006 (UTC)


Wikipedia is not censored. If people use the mnemonics, they should be noted. However, I think we should establish some kind of notability criteria for the ones we include, since anyone can just make a new one up. Maybe a threshold of google hits or something? — Omegatron 17:52, 31 December 2006 (UTC)


The one I remember from school was: * **Bad Boys Rrape Our Young Girls But Violet Gives Willingly - - Bdelisle 07:04, 31 January 2007 (UTC)
According to WP:Profanity, "Words and images that would be considered offensive, profane, or obscene by typical Wikipedia readers should be used if and only if their omission would cause the article to be less informative, relevant, or accurate, and no equally suitable alternatives are available." We have MANY more alternatives in that section, and not including them is not of detriment to the article in any way. They have been removed. --Dancraggs 11:06, Monday May 7, 2007 (UTC)

[edit] Resistor series

There are series of resistor values, namely E6, E12, E24 - these have a geometric sequence relation to each other in their resistance value, take a look at preferred number to see what I mean. According to that article, International standard IEC 63 defines those values.

--Abdull 15:20, 19 Jun 2005 (UTC)

[edit] Resistance of a True Vacuum

I always thought that a true (ideal) vacuum would have an INFINITE resistance. Am I Wrong? ?. If not, this reference should be deleted.Light current 15:26, 3 August 2005 (UTC)

It's more complicated than that. Yes, a vacuum can carry current. This is how vacuum tubes work. - Omegatron 15:41, August 3, 2005 (UTC)
No, it's exactly that simple. In a true (ideal) vacuum, there is nothing to carry a current, therefore resistance is infinite. A vacuum tube works by modulating the passage of electrons from the hot filament or cathode to the positively charged anode. So that these electrons don't bump into stuff on their way, as much as possible of everything else is removed from inside the glass envelope. Coloquially, that makes a vacuum, hence the name. This does not mean that there is nothing in there when a current is passing.--GrahamDavies 18:35, 11 September 2007 (UTC)

[edit] RESISTANCE of CONDUCTORS NOT APPROPRIATE

This article is about RESISTORS so I have removed the bit about resistance of CONDUCTORS. This is better put under the article on resistanceLight current 07:24, 1 August 2005 (UTC)

[edit] Symbol for a resistor

In other languages (see the German or Italian article), the symbol for a resistor is a rectangular box. This page claims that this is also true in the UK.

Is there some sort of international standard concerning these symbols and should this page reflect other internationally used symbols? Kusma 00:51, 21 October 2005 (UTC)

It is the rectangle box in NZ also. I think the zig zag line in the North American symbol and the box is the symbol for pretty much everywhere else. --antilived T | C 03:34, 28 November 2005 (UTC)

I added the rectangular box symbols. Could possibly be improved to describe where each symbol is used and what standards apply. EdC 13:29, 3 March 2006 (UTC)

The rectangular box is the standard symbol for all components, to be a resistor it must have an R, similarly inductors have L, capacitors C, impedences Z. FrstFrs 21:10, 30 January 2007 (UTC)

[edit] Request link correction

I am in the process of disambiguating the Power disambiguation page. This means I find links to Power, and try to figure out which of the several power related articles were really intended. This artice contains a link to Power which should actually be a link to Power rating. Since the page is protected, I request that someone with authority to edit the page make the improvement. Gerry Ashton 20:24, 25 May 2006 (UTC)

[edit] current is flow!

First off, if I have used the template above incorrectly please let me know...

The second sentence has the redundancy ""... divided by the current that is flowing through the resistor."" It should read sans "that is flowing" and be simply ""... divided by the current through the resistor.""

Again the second sentence under "The idea resistor"; "... remains constant regardless of the applied voltage or current flowing through the device." Should be written w/o 'flowing'

The last sentence prior to "Power dissipation" also contains this error "...break down and admit a larger flow of current under sufficiently high voltage." w/o 'flow of'.

Those are the only three that I found, there seem to be many more correct usages than incorrect. Thank you Admins for your attention... ~--Ketter 02:09, 4 June 2006 (UTC)

I have simply unsprotected the page so you can do this yourself. Kusma (討論) 02:54, 4 June 2006 (UTC)


[edit] Adding table for material/background-color?

Not sure if it's accurate, but I remember from one of my schoolbooks a chart showing how the background-color of a resistor (the typical kind with color-rings to show value) corresponded with the material used. E.g. white=carbon-film, blue=some metal-oxide (can't remember, it's been 15 years :-). If someone had such a table (and if resistors are still coded this way), it would be a great addition to this page. --koppe 10:00, 6 July 2006 (CET)

Background color isn't used anymore although most mfrs have standardized on tan for carbon film & blue for metal film. Most metal oxides are gray but some are light blue, green, or violet. AerospaceEngr 16:49, 22 August 2007 (UTC)

[edit] High voltage transmission

Why is power(electric) transmitted at high voltage when power loss due to ohmic heating is V2/R as well as I2R? Why does the ohmic loss decrease with increase in the amplitude of the voltage(Of AC)?Subhash

You seem to have mis-applied those formulea, In V2/R , the "V" that's being refered to is the voltage drop along the transmission line, NOT the overall transmission voltage. Since the voltage drop is proportional to the current through the line (OK, this is an over-simplification, but accept it for now), that leads to the I2R formula for the power loss in a transmission line. So this means that the power wasted in ohmic heating of the line is proportional to current squared, since power is current x voltage ( another over-simplification, but close enough ) and you have to transmit a certain ammount of power, by choosing to do it at a high voltage, less is wasted in heating becuase the current is lower. Astaroth5 09:08, 14 August 2006 (UTC)

Thank you.Subhash

[edit] ERROR in resistor color codes!

"The Standard EIA Color Code Table per EIA-RS-279 is as follows:

black=1 brown=2 red=3 orange=4 yellow=5 greem=6 blue=7"

This is in error and is incomplete: Green is misspelled; more importantly, the numbers are off by 1. It should read:

black=0 brown=1 red=2 orange=3 yellow=4 green=5 blue=6 violet=7 grey=8 white=9

As per any number of online references. Precision resistors are often confusing to the novice and even to some experienced people. Additional color bands will indicate more information such as much tighter tolerances and temperature coefficient, though these types are not often seen by most users. In practice, the tiny size of the bands and their precise coloring can be difficult to discern; I'm having to use a magnifying glass these days!


--Damon Hill, damon161@comcast.net

??? You must be looking at some cached version of the vandalized page. I reverted that vandalism on Nov 16th! Alfred Centauri 23:52, 18 November 2006 (UTC)

[edit] More Vandalism....

I am reading this page 13 Feb 2007. It has been vandalized again. Unfortunately... I do not know enough about the subject to correct it. --71.170.63.164 04:01, 14 February 2007 (UTC)

Can u track down the vandalizer in the history section and send him/her a warning? [[[User:XU-engineer|XU-engineer]] 22:04, 31 July 2007 (UTC)

[edit] Resistor: An Electron Device in the Field of Electronic Device and Materials

As the topic of Resistor is a vital element in the field of Electronics the page must include basic science information about what the device is in terms of applied materials physics and materials chemistry. When I add this knowledge it is deleted "as a cut and past" actually no. It was, however, free hand from my head and my deep understanding and research, (So adopt me if the style is not good enough for the page, and I will comply. Or if you need references thats OK too...) I do feel some representation of the Materials Science / Applied Physics is appropriate if you also have a Technology section that lists varios "material based" resistive schemes. As the simple Man made color coding and material composit choices to make a resitor are interesting for a hobbiest, it in no way defines 'what' a resistor is in natural terms. To be more concise the terms to define a resistor should not be by the word resistor or some ratio relative to other properties of electron resistance through a material. To be a vital representation; the atomic understandings as of 'today' of the electron in a material needs to be expressed here 'as a free charge carrier' in the conduction band of the material for a deeper understanding for all, than just man made constructs describing man made elements. Some may have expressed recent additions as cut and past and reverted the post (A1 to bad), others may have seen the possibility for expansion with citation into material science and physics to provide more depth of understanding for others... In any case my post was not cut and past, its from 20 years in the field and trying to boil the facts down for others to have a clearer understanding of what a "resistor" is in electronics by documented research in the field of Electronic Devices and Materials. Insert non-formatted text here

If you say its not cut and paste, then i will believe you as most people wouldn't bother to debate this. Anyhow, if you re-instate it with some references, that is great! I think it needs a little grammatical and some potentially scientific tuning, but sure, just move your work into the latest revision. Remember nothing is lost on wiki! My apologies if you think there is some barrier to entry that i have thrust upon you. User A1 11:30, 5 June 2007 (UTC)