General > General Technical Chat
Do you think an LED is a resistor?
Kim Christensen:
--- Quote ---Ok, it really is basic comprehension of inclusion.
--- End quote ---
Yea, and you fail it badly! :-DD
And now, I'm going to "unsubscribe" to this thread, and leave you to your "own devices".
MK14:
--- Quote from: Sredni on April 24, 2024, 03:00:03 am ---This is a set of...
of...
...nonlinear resistors!
Yeahhhhh!
Now take this big huge set of nonlinear resistors, and put it near the set of linear resistors (they also have their own symbol).
What have you got now? What is the set formed by the set of linear and nonlinear resistors?
It's a set of...
...
Resistors!
Yeahhhh!
--- End quote ---
I hoped (it was somewhat intentional on my part), that my recent post(s) in this thread, would elisit, more information from you (the OP), as to what you thought was going on, and it seems to have worked, as you seemed to have done that.
In summary and as a sort of analogy, this is how I seem to understand, the point(s)/concept(s) you seem to be trying to portray.
(Hypothetically speaking, i.e. I have NOT just done this).
I create an interesting and long new thread on here, describing my new $50,000 electric car, which happens to have (very approximately), a 100 volt battery set up, along with a 100kW motor (engine if you like). I have then described the technical details, of all its (interesting to some) systems and functionalities.
You have now jumped into my (hypothetical) thread, and said ...
"no no NO NOOOOOOO!!!!, what nonsense MK14 is talking ......"
This is all really a 1 milliohm resistor (non-linear resistor), with a supplied link to a set theory YouTube video, for very young people.
So, although there is a little bit of technical merit (correctness), and the $50,000 new car, is a bit like (sort of, at a stretch of the imagination), a 1 milliohm resistor (non-linear).
The vast bulk of the time, and to almost everyone, it is NOT a useful, interesting or good way of expressing, what it is.
E.g. Which thread title would people be more likely to click on?
"I just bought my great new, $50,000 super fast electric car, technical details of all its electronic systems included, with advanced AI self-driving to level 3"
Or
"Today I bought a 1 milliohm, (non-linear) resistor"?
The start of the thread then says...
100V 100kW (max)
I hope my analogy is accurate?
TopQuark:
The terms resistor or diode are just words we humans coined to describe certain electrical devices with a specific electrical property, to help us engineers abstractly express how our circuit design works and it's expected behavior.
There's no reason why you couldn't call every 2-leaded device as a resistor:
- A diode is a non-linear resistor that conducts current exponentially with applied voltage, and only in one way
- A capacitor is a giga-ohm resistor with two electrodes that conducts through dielectric materials, it also happen to store charge too.
- An inductor is a low-value resistor made with coils of copper wire wrapped around something, that also happens to store energy in the magnetic field.
Go ahead, replace all your schematic symbols with resistors.
If a p-n junction can be described as an resistor, they why not draw your pnp junction transistor as a few resistors too?
Go ahead, when your boss or client asks you to design a circuit, send them a page of resistors. Next time you buy a CPU for a PC, ask for a package of 1 billion integrated non-linear resistors too! See what you get.
The fundamental reason a resistor is a resistor, and a diode is not a resistor, is because we engineers decided it is just easier for everyone to agree on using terms to abstractly describe devices with different classes of expected behavior.
It is non productive to call everything "resistor, but non-linear", "resistor, but stores charge", "resistor, but inductive". We decided there's a line in the sand where we split all these "resistors" into different abstract things, giving them different names "diode", "capacitor", "inductor" while reserving "resistor" for the linear device we already understand it to be.
You can invent your own method of describing a circuit. You can invent your own mathematical system. You can invent your new language. We simply agreed on what we commonly use to get everyone on the same page, and not having to explain everything from scratch every single time.
Berni:
--- Quote from: Sredni on April 23, 2024, 06:35:27 pm ---
--- Quote --- They are not. The resistor is the industry standard term for a device that is designed to create the effect of resistance in a well defined manner. While electrical resistance is a physics phenomenon where something opposes the flow of current in a electrical circuit.
What is the point you are trying to make with this thread? That a diode has electrical resistance? Or that everything that exhibits electrical resistance should be called a resistor?
--- End quote ---
I am trying to uncover the roots of this cognitive dissonance. First you say that varistors are resistors that... And then you say no, they are not resistors, because resistors are only linear.
Go on that Vishay page that shows how to simulate nonlinear resistors (a term that up to a few messages ago you people thought I had invented, LOL) and simulated your resistor with an exponential characteristic. There you have your diode. It is a nonlinear resistor.
--- End quote ---
Yes a resistor that is designed to exhibit high nolinearity is called a varistor, this is to not confuse it with a regular resistor that is meant to have just a well defined resistance as the primary characteristic.
So this thread is indeed just about you not agreeing with how things are named.
I don't decide what the industry decides to call things. I just follow the already established naming conventions so that there is no confusion about what we are talking about to the majority of people in the field. The purpose of giving things names is to facilitate communication. Sure not all names for things are the best choice and sometimes they are obsolete historical reasons for the origin of a name, but it is what it is.
The laws of physics don't change if you change the name of a device. This thread shows that the vast majority of forum members agree upon what a resistor is and it also agrees with what Wikipedia defines as a resistor. So i am going to continue using that definition of a resistor as it clearly is the more prevalent industry standard.
Nothing really to gain from arguing about already established naming conventions.
So i am leaving this thread. See ya :-+
ebastler:
Sheesh... how long do you guys plan to continue this?
"Resistor", without any qualifier, is used in practice to designate a component which exhibits ohmic resistance. Strictly speaking, one should use the term "ohmic resistor" for that type of component, and reserve the unqualified "resistor" as the generic term for ohmic and non-linear resistors. But in practice, nobody does that.
We also use special terms for non-linear resistors with specific properties -- diode, varistor, NTC, PTC etc. -- and don't refer to them as "resistors". Otherwise, confusion would ensue since "resistor" is so commonly used to refer specifically to ohmic resistors.
So Sredni is right, in a fundamentalist, "how many angels on a pinhead?" kind of way -- which seems to give him great satisfaction. But in practical terms, everybody else is right.
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