0 Ohm resistors

[madmaxbryan]

What is the purpose of 0 ohm resistors? I have noticed a lot lately that most of the boards i assemble at work are using 0 ohm resistors rather then simply using jumper wires. For us the process is exactly the same for both jumper wire and resistors, same axial sequencer/inserter, same wave soldering process, same everything on our end. so wouldn't it be cheaper to use jumper wires rather then 0 ohm resistors?

[dmlandrum]

I remember someone explaining on another board that pick and place machines have problems placing with little bits of wire, so they make the little bit of wire look just like a resistor and call it 0 ohms. Something like that, anyway.

[DavidDLC]

They could be also to make selections, like decimal places on Panel Meters.

In the other hand 0 ohm resistor looks much better than wires.

[madmaxbryan]

as far as i know, pick and place machines cant be used at all for through hole parts, thats why we use an axial sequencer and axial loader. it bends and loads jumper wires just as good as it can for resistors or any other axial component

[PetrosA]

0 Ohm resistor sounds like the kind of oxymoron Kurt Vonnegut or Joseph Heller would have thunk up

[Kiriakos-GR]

Well for true low ohm bridges , only the silver wire can do the trick. 
But it costs a bit.

[Simon]

even silver wire will have an infinitesimal resistance. The term "0" ohm resistor really is just saying a jumper in the form of a resistor case

[Psi]

0 ohms are quite handy when you want to make it easy for areas of your circuit to be disconnected from each other.

For example, they quite often put one 0 ohm resistor in each power rail in cellphones (there are often 10 or so power rails for various things). It makes it easy to debug when you're trying to optimize power usage and reduce usage when in cpu sleep modes.

You can unsolder a few 0 ohms and watch the overall current to see which area of the circuit is drawing power when it shouldn't be.  You can also replace the resistor with some wires and measure the current directly.

[mikeselectricstuff]

Many years ago the  Farnell catalogue had some 0R resistors listed with a 5% tolerance spec...

[madmaxbryan]

so what is the point of using 0 ohm resistors over jumper wires? since a 0 ohm resistor is just a jumper wire with a resistor casing on it.

[jahonen]

For SMD pick and place machines, chip 0R resistors are considerably more suitable than just a piece of wire. Most typical use for them here is to add possibility to easily cut signals when debugging designs if there are uncertainties involved, and they are usually removed at final stages of product development.

0R resistors are something like 50 milliohms in reality. I had a case where I had to change 0R jumpers (used for prototype testing purposes) to 10 milliohm resistors (also used in the product), due to that the 0R resistors had inconveniently large voltage drop (three in parallel) for the current.

Regards,
Janne

[RayJones]

Many years ago the  Farnell catalogue had some 0R resistors listed with a 5% tolerance spec...

They also list a power rating too! sort of crazy with "0" entered into the good ol I2R

[madmaxbryan]

i can understand the usefulness of them in surface mount boards, but what about in through hole boards?

[Strube09]

I frequently use "0" Ohm resistors to allow for selecting options on my PCBAS.

We have some boards at my work that are all the same layout and software but by populating the board with a 0Ohm in one slot or a 0Ohm in second slot activates powers different hardware or software options. Cheaper and smaller than dip switches

Strube

[madmaxbryan]

so heres a picture of what im talking about:


I would think it would be cheaper to use the jumper wires they use in that picture rather then 0 ohm resistors.

[Psi]

i think in through hole boards the zero ohm resistors (actual resistors with one black band) are mostly used as poor mans fuses. ie, intended to be a point of failure that is easy to detect/replace.

Another reason maybe that, since the are the same size/shape as normal resistors, they can be used in whatever equipment or gear you might have in production/assembly that uses normal resistors.

If you used wire instead you'd have to get it pre-bent to the right width or bend it yourself. Neither option would be as cost effective as a zero ohm resistor which can be produced in huge quantities easily with existing resistor manufacturing gear and meets specific standards on size/width etc..

[apex]

In a gadget I built about a year ago, I used zero ohm resistors as extremly low value shunt resistors.
Their range is from 10 miliohm to about 100 miliohm.
Since my device was self-calibrating, It could use about any resistor given...

apex

[Simon]

what I don't understand is if there are under 10mOhm resistors why are "0" ohm resistors well over that in some cases ? I mean all you really need is a chuck of copper of the correct size possibly with a paint coating around the middle

[Zero999]

My guess is the 0 Ohm resistor manufacturers are just covering themselves for the worst case scenario. In real life, they're most likely to be much less than 0 Ohm. 10m Ohm resistors are also normally surface mount and physically larger than some 0 Ohm resistors.

[Wim_L]

My guess is the 0 Ohm resistor manufacturers are just covering themselves for the worst case scenario. In real life, they're most likely to be much less than 0 Ohm. 10m Ohm resistors are also normally surface mount and physically larger than some 0 Ohm resistors.

Neat! Cheapo two-wire amplifiers, no need to order tunnel diodes anymore 

[RayJones]

Add a flux capacitor and the time machine is ready for action.

[Wim_L]

They're great for charging batteries too!

[Simon]

My guess is the 0 Ohm resistor manufacturers are just covering themselves for the worst case scenario. In real life, they're most likely to be much less than 0 Ohm. 10m Ohm resistors are also normally surface mount and physically larger than some 0 Ohm resistors.

You work for Farnell ? first they are 5% on 0 ohms now they are less than 0 ohms 

[Zero999]

My guess is the 0 Ohm resistor manufacturers are just covering themselves for the worst case scenario. In real life, they're most likely to be much less than 0 Ohm. 10m Ohm resistors are also normally surface mount and physically larger than some 0 Ohm resistors.

Neat! Cheapo two-wire amplifiers, no need to order tunnel diodes anymore 

Lol, I think you probably know what I meant though.

[Simon]

err not really but I'll pretend i do