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EIRE2003
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Why would a circuit have a zero ohm resistor (3 black bands) in it?
EIRE2003 said:Why would a circuit have a zero ohm resistor (3 black bands) in it?
And often they are placeholders for low value resistors whose value you haven't decided on yet. Also, you use zero Ohm resistors to let you stuff different configuration options.faust9 said:Zero ohn resisitors are used as jumpers.
berkeman said:Also, you use zero Ohm resistors to let you stuff different configuration options.
You wouldn't run into this use of zero Ohm jumpers on a production board, probably. But on test and prototype assemblies, especially mixed signal analog + digital emulation boards, you often are not sure what the best configuration will be in an analog area. So if there are two or three likely candidate configurations of the basic topology, you put all the hooks into be able to switch between the configurations by stuffing different combinations of zero Ohm jumpers. Parasitics are often a concern in analog circuits, so you don't want to have to be reworking flying components too much onto an SMT assembly to try different options. I'll use the SMT zero Ohm jumpers to short around a component that I want to remove from the circuit (like a signal transformer) for particular characterization tests, for example. Or maybe I want to try a couple different topologies of an analog filter section, so I'll place zero Ohm jumper positions in places that I can use to change the way the parts are connected in the filter. Make sense?EIRE2003 said:What do you mean there?
It doesn't have to be directly across the PS to have a voltage on it.dlgoff said:I don't think you would put them across your power supply. If you did, you would either smoke the wire or your supply(if not current protected).
LOL. You use them for interconnect, just like wires and traces. Not as a circuit element. Funny guyOuabache said:Hmmmmm... A zero ohm resistor sounds like a weird item indeed... We know that even "wire" has some resistance per unit length. It would be logical to say that a "zero" ohm resistor then has some finite resistance. Suppose you put an voltmeter across this resistor. Let's say 5Vdc was the potential preceding the zero ohm resistor. How much current would you say is running through the resistor?? I = V/R = 5/small = 5/.0000001 = 250MAmps That would burn up! Even a small potential above such a resistor would measure a large current through it.
So how do you avoid such a high current through a zero ohm resistor?
Hey, I just remembered an application for zero Ohm jumpers where they are actually used in high volume production of low-cost assemblies. I'd make it a Quiz Question for y'all, but it's probably too obscure.berkeman said:You wouldn't run into this use of zero Ohm jumpers on a production board, probably.
I'm no help on that question, unfortunately, but we will sometimes use a wirewound resistor as an inductor in special situations. Good question, though.matejhowell said:I have another question on the same topic. Does anybody have any more analog (as opposed to digital -- like a switch -- or mechanical -- like PCB layer avoidance) ideas for the use of 0 ohm resistors? the reason why I ask is because they are sold with very high, very specified ratings (like a surface mount zero ohm resistor from Dale/Vishay might be rated at a maximum current of 4 Amps). Why not make it metal, just like a wire, that might not be rated so high in current? If they have specific deliberate attributes, it seems they might have a component purpose? ... just a question...
MH
A zero ohm resistor, also known as a jumper or shunt, is typically used as a placeholder in a circuit. It allows for easy connection between two points on a printed circuit board (PCB) without having to physically solder components together. It also provides a means to change the electrical path in a circuit without having to remove or replace other components.
The color bands on a resistor indicate its resistance value according to a color code system. However, a zero ohm resistor has no resistance value, so the 3 black bands are used as a placeholder instead. This is to differentiate it from other resistors that do have a measurable resistance.
In most cases, yes, a zero ohm resistor can be replaced with a wire. However, using a zero ohm resistor allows for easier troubleshooting and modifications in a circuit without having to cut and re-solder wires.
The main drawback of using a zero ohm resistor is that it takes up physical space on a PCB. This can be an issue in compact electronic devices where space is limited. Additionally, zero ohm resistors can be more expensive than a simple wire, so cost may be a consideration in large-scale production.
No, a zero ohm resistor cannot be used as a regular resistor. Its purpose is solely for connecting two points in a circuit, and it has no measurable resistance value. If a circuit requires a regular resistor, a zero ohm resistor should not be used as a substitute.