Has the poll answers text been changed?
I might start a new thread because this is so interesting -
Do you think a Vise-Grip is a hammer?
After all, I can hammer a nail with a vise-grip. If I give you two pieces of wood with driven nails - can you tell which one had the nails driven with a hammer and which one has nails driven with a vise-grip?
So I want to know if a vise-grip is in fact just another form of a hammer. Prove me wrong.
non linear system has linear approximation around a small operating point....
STOP THE PRESSES!
... oh wait, that's the underlying principle of how spice AC analysis works.
Small signal analysis has nothing to do with what we are discussing here.
The resistance I talk about is the static resistance, not the dynamic or incremental resistance of small signal analysis.
Try again.That was your long winded and dithering proof:So, we are now seeing the diode as a voltage dependent resistor. Let's see... what is the resistance 400mV? Let's zoom in:
[MASSIVE IMAGE]
I'd say it's about 23.2 kohm.
Let's see what is the resistance at, I don't know, 660 mV (about 5mA of diode current). We can compute it by hand of course, but on the graph we see it is 132 ohm.
[MASSIVE IMAGE]
Now, let's see if we can make something with these values...
[snipping conversational fluff]
Ok, exact same results, if we neglect a bit of rounding error in reading and setting the values.
Now, take your black boxes out of the fridge. Put the diodes D1 and D2, and the resistors R1 and R2 inside a black box each. Shuffle them around. And tell me: without looking inside the black boxes and without resorting to second order effects (like temperature dependence, or changing the other circuital parameters to change the operating points) can you tell me which are the diodes and which are the resistors, by simply measuring voltages, currents and powers?So to try and claim you're not relying on the well known small signal AC parameters is plainly incorrect.
If you dont like relying on small signal characteristics, perhaps "try again" with your explanation/justification.
I might start a new thread because this is so interesting -
Do you think a Vise-Grip is a hammer?
After all, I can hammer a nail with a vise-grip. If I give you two pieces of wood with driven nails - can you tell which one had the nails driven with a hammer and which one has nails driven with a vise-grip?
So I want to know if a vise-grip is in fact just another form of a hammer. Prove me wrong.
I was also thinking on mechanical lines
... so if the electrical terms Resistance, Inductance and Capacitance have their mechanical equivalents what is the OPs mechanical device analogous to the LED?
what is the OPs mechanical device analogous to the LED?
I am still NOT convinced. I don't think an LED and a resistor are the same.
Apart from anything else, an LED is normally used as a light source or indicator. Functions which a normal, non-overloaded resistor can't do. At least in the visible spectrum.
For example if the valve is open and you want it to close, it requires a small amount of backflow to make it shut off
Resistor < Linear resistor U Nonlinear resistor
Nonlinear resistor < incandescent lamps U diodes U ...
So, you can still call it a diode, recognize that it is a nonlinear resistor and, as such, that it belongs to the more general set of resistors.
Does this make any sense to you?
It does not make sense.
All resistors exhibit electrical resistance.
All of those semiconductor devices indeed also exhibit electrical resistance.
However not all devices that exhibit electrical resistance are resistors as they are not components purposely designed to implement a well defined resistance.
Does not matter what you understand as "resistor", the vast majority of forum members you are talking to on here understand it as a device specifically designed to implement a well defined amount of resistance. You don't have the authority to redefine established industry words used by others.QuoteWhat you are trying to say is that a diode exhibits the effect of "electrical resistance" or "resistivity".
This effect is not particularly special and just describes that the device can consume electrical power and turn it into something else,The point I make is that this is ALL a diode does.
Huge resistance when reverse biased, small resistance when forward biased. This is not a side effect. It is what it does (if we neglect secondary effects due to parasitics in real devices).
It does not store energy in the electric field.
It does not store energy in the magnetic field.
It does not do whatever sorcery a memristor does.
It just oppose a resistance that takes power out of the circuit.
Yes we all agree on here that at some fixed DC operating point a diode acts like resistance.
The point is that a diode is nothing special at doing this. The laws of physics force all power consuming components to look like resistors in steady state DC. This means that at a fixed DC operating point even a memristor is actually just electrical resistance, much like a diode acts as purely electrical resistance at that DC state.
Like what else do you expect an component to do at DC? It can either act as a power source (like a voltage or current source) or it can resist the flow of current hence resistance. There is nothing else for a component to do at DC.
Second condition is sometimes relaxed - e.g. variable resistors, thermistors, light-dependent resistors - but they are never called just "resistors", but with resistor only as part of the full name.
I don't suggest renaming something which already has another name, though, such as "light-emitting diode", as "non-linear light emitting resistor", even if you technically could. Maybe if it was originally named that way, we would be fine with the name. Then we would likely see Sredni creating a thread about how this non-linear resistor should be actually called a "diode".
This is not about the naming per se, it is about the fundamental nature of a diode from the point of view of the circuit. All it does (neglecting secondary effects) is offering a resistance.
Is an LED a resistor?
No. It has a different name, so it is not a resistor
Yes. It is a resistor, just not an ordinary one
You don't seem to realize that no one has an issue with a LED, or any other device, having resistive properties.
People here seem to have a problem in understanding set inclusion.
This is not about the naming per se, it is about the fundamental nature of a diode from the point of view of the circuit. All it does (neglecting secondary effects) is offering a resistance.
Now you say it... yet your poll asked this:QuoteIs an LED a resistor?
No. It has a different name, so it is not a resistor
Yes. It is a resistor, just not an ordinary one
You don't seem to realize that no one has an issue with a LED, or any other device, having resistive properties. We have an issue with you calling it a type of resistor.
resistance vs resistor
Do you think they are trolling?
Yes, because the mental block a lot of people have in recognizing that a diode (an LED) is a resistor seems rooted in the fact that it has a different name.
As if giving it a specific name could change its fundamental nature.
Go tell Vishay they are using an 'oxymoronic' terminology.
After all what could they know about electronic components?
There is so much to unpack here but let's consider only the last part.
A capacitor at DC can hold a voltage without passing current; try to do that with a resistor.
An inductor at DC can hold a current without a voltage (if ideal, and a small voltage due to small resistive losses if real). Try to do that with a resistor.
You can use these properties to create memory cells. Try to do that with resistors alone.
I am not well versed in memristors to give an elementary setting that shows their fundamental difference from resistors, but I am pretty confident you got that part wrong, as well.
Have you looked up the Science Direct link I gave above? I am not redefining industry standard terms: diodes have been considered to be nonlinear resistors for decades. You just wasn't aware of it.
Have you looked up the Science Direct link I gave above? I am not redefining industry standard terms: diodes have been considered to be nonlinear resistors for decades. You just wasn't aware of it.
Yes and we have names for a resistive device that is designed to be very non linear, the industry standard term for that is a varistor instead of resistor.
...a resistor where its resistance is strongly affected by the voltage across it is called a varistor or "voltage dependent resistor". So if you are to draw similarities, you can say a diode is a form of asymmetrical varistor.
The only problem is that you are throwing around the term resistor and resistance as being the same thing.
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?
Here
https://www.vishay.com/docs/29235/elecsimtoolkitvishaynlr.pdf
Go tell Vishay they are using an 'oxymoronic' terminology.
After all what could they know about electronic components?
Here
https://www.vishay.com/docs/29235/elecsimtoolkitvishaynlr.pdf
Go tell Vishay they are using an 'oxymoronic' terminology.
After all what could they know about electronic components?
Hit CTRL-F and search for the word "diode" in that document. There are only 3 occurrences of the word diode. In none of those sentences do they claim that a diode is a resistor.