Oxymoronic 0 Ohm resistors - Page 1
Forum section: electronics / beginners

author: EvilGeniusSkis
author_rank: Regular Contributor
timestamp: June 26, 2015, 12:09:31 pm
content: I understand the usage of SMT 0Rs, but I do not see the point of 0R TH resistors; wouldn't a bit of wire be cheaper.

author: McBryce
author_rank: Super Contributor
timestamp: June 26, 2015, 12:12:03 pm
content: If you can get a pick and place machine to place the wire yes, but a wire that needs to be manually inserted will costs more.McBryce.

author: cowana
author_rank: Frequent Contributor
timestamp: June 26, 2015, 12:13:47 pm
content: As component cost, yes.However, assembly companies are already fully setup for automated unpacking, bending and preparing resistors for population, so a 0R resistor is no different. Using a small piece of wire would not be possible using the resistor lead-forming equipment - it would have to manually be cut to length, stripped, bent...So the answer is that a 0R resistor is cheaper when you factor in the assembly time.

author: AndyC_772
author_rank: Super Contributor
timestamp: June 26, 2015, 12:14:05 pm
content: Hands up who has ever been asked whether a 0R resistor should be 1% tolerance or 5%.

author: McBryce
author_rank: Super Contributor
timestamp: June 26, 2015, 12:23:08 pm
content: Quote from: AndyC_772 on June 26, 2015, 12:14:05 pmSo what's 5% of 0?And wouldn't I need to keep them at absolute zero for them to be accurate at all?McBryce.

author: madires
author_rank: Super Contributor
timestamp: June 26, 2015, 12:36:54 pm
content: Quote from: AndyC_772 on June 26, 2015, 12:14:05 pmIf you got a milliohm meter with 4-wire/kelvin probes you would find out that the 0R resistor got a few milliohms. There must be something very wrong

author: sleemanj
author_rank: Super Contributor
timestamp: June 26, 2015, 12:49:04 pm
content: Quote from: EvilGeniusSkis on June 26, 2015, 12:09:31 pmI use 0R through hole all the time when doing single sided homemade boards, especially if the board is intended for copper-side-upit's easier than cutting and bending solid wireIt's tidier than stranded wire jumpersIt's faster than stripping enamel coated wirethe "resistor" body holds the legs off the board so they won't short to the copper traces underneathtop-side-soldering them looks much nicer for copper-side-up boards (ie surface mount buttons etc) than having solder tails sticking up at you from bottom side jumper wiresI use 1206 as well when i only need to cross one trace.In industry it's more about already having machinery to handle resistors, so two birds with one stone.

author: free_electron
author_rank: Super Contributor
timestamp: June 26, 2015, 01:22:40 pm
content: Quote from: AndyC_772 on June 26, 2015, 12:14:05 pmreal men use temperature compensated, oil filled, 0.001% 0 ohm resistors and wire them in kelvin configuration on teflon standoffs. !

author: Delta
author_rank: Super Contributor
timestamp: June 26, 2015, 05:04:10 pm
content: Standby for my Kickstarter - "Graphene constructed, cryogenically quantum treated, audiophile grade zero Ohm resistors".

author: SeanB
author_rank: Super Contributor
timestamp: June 26, 2015, 05:19:23 pm
content: The only time I have seen machine inserted wire links is in copiers and printers, where they will do wire links, either to use a single sided SRBP board ( cheap and can be made either additively using a screen printing process, or which can be etched fast) and up to 300 wire links, or on a double sided board so as to avoid having to use a multilayer board, but still having a ground plane on the board for EMI reduction. There they also often did the board as double sided but without through hole plating, using the component leads and links as connections to the top side traces. Top side was hand soldered as well with the bottom being wave soldered.Saw a Sharp copier board with literally a single mask MCU, a decoupling capacitor, a crystal and 2 capacitors and a quartet of components for reset, and 300 wire links in neat rows across the board, in 2 orientations and 4 different lengths. All this and around 11 multipin connectors to the rest of the machine. You might have up to 10 wire links on a single trace, from one connector and going to another. All this to use a single sided board. It must have been cheaper than going double sided through hole plated by at least a few cents.

author: mazurov
author_rank: Frequent Contributor
timestamp: June 26, 2015, 06:24:53 pm
content: Resistors are cheaper than wire these days. You buy a thousand Chinese LEDs on eBay, you get a thousand of shitty Chinese resistors of some value as a bonus. I have a bottomless bag of those on the bench to cut the legs off of when I need a piece of tinned wire to short something together.

author: xrunner
author_rank: Super Contributor
timestamp: June 26, 2015, 06:33:28 pm
content: If it's Zero ohms ... then it ain't a resistor 'cause it ain't resistin' anything.

author: Neilm
author_rank: Super Contributor
timestamp: June 26, 2015, 07:55:34 pm
content: There is a datasheet for a series of resistors that we have at work. Part of the spec states something along the lines of "+/- 1% +/- 10mohm" for values less than 1 ohm. I haven't yet seen any of the "Zero ohm links" that are in the range with a negative resistance.

author: free_electron
author_rank: Super Contributor
timestamp: June 26, 2015, 10:23:08 pm
content: Quote from: Delta on June 26, 2015, 05:04:10 pmmade from old coathangers. cause they sound the best. especially if they were used to hang woolen clothes. stay away from coathangers that were used for synthetic fibers. those are only good to play kraftwerk music,

author: Psi
author_rank: Super Contributor
timestamp: June 26, 2015, 10:34:16 pm
content: It's really interesting when you get a +/- 1% 0 ohms resister in the left side of the bell curve

author: McBryce
author_rank: Super Contributor
timestamp: June 28, 2015, 09:16:24 am
content: Quote from: Delta on June 26, 2015, 05:04:10 pmShut up and take my money!!! Where do I make my pledge!? Will you be goldplating any and all visible metal on them? Does it come in a hand carved presentation box?This would be perfect for discharging those Audio Grade Capacitors I bought for €8K last week.McBryce.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: June 28, 2015, 10:29:39 am
content: Quote from: AndyC_772 on June 26, 2015, 12:14:05 pmBoth are available....http://uk.farnell.com/multicomp/mcf-0-25w-0r/resistor-carbon-film-0r-0-25w/dp/9339027http://uk.farnell.com/vishay-bc-components/mba02040z0000zrp00/thin-film-resistor/dp/1772532

author: SeanB
author_rank: Super Contributor
timestamp: June 28, 2015, 10:54:23 am
content: So basically they give you a untrimmed resistor when you select a 0R option, using the film that they put on the lowest value ( 1R for the MCF, 0R22 for the Vishay) and not trimming it, so it will only have a maximum limit value of 1R or 0R22. Actual value will be batch dependant, and position in the batch as well. At least you can be sure they will be non inductive though.......

author: Jope
author_rank: Regular Contributor
timestamp: June 28, 2015, 12:36:37 pm
content: Quote from: SeanB on June 28, 2015, 10:54:23 amNo. Farnell just goofed up on the description. Take a look at the manufacturer code of the Vishay 0-Ohm resistor (MBA02040Z0000ZRP00) and at the datasheet. The Z means 'jumper', with a resistance of >= 10mOhms, according to datasheet.

author: sunnyhighway
author_rank: Frequent Contributor
timestamp: June 28, 2015, 08:10:08 pm
content: Quote from: Jope on June 28, 2015, 12:36:37 pmSo that resistor would have a precision of ?%Not sure what color that ring would be...

author: EvilGeniusSkis
author_rank: Regular Contributor
timestamp: June 28, 2015, 09:52:28 pm
content: Thanks to everyone who explained the use of 0R TH resistors, now here's my comedy piece: "Join the resistance and help us reduce our mortal enemy, the current!"