Artificial Life Experiments Show How Complex Functions Can Evolve

NSF ^ | May 8, 2003 | Staff

[null and void]

Sorry, I left off "In that program..."

[AndrewC]

With a bit of practice you could turn out one, maybe two a day...

Hey, you must be pretty good! For a 1 gram carbon resistor you would be precise to around 50 micrograms.(lots of assumptions in your favor) Pretty deft with a file.

[Ichneumon]

Still trying the red herring.

Yes you are. Getting tired of that stale fish yet?

I stated it won't work.

You did, knowing that most people here don't have the background to realize how baldfacedly you're lying.

In a sense, means in a sense.

Nice tautology. Care to make some sort of point?

Junction transistors are not fabricated by putting two diodes back-to-back. They are fabricated by a process of doping(appropriate to you) and redoping(still appropriate to you) a silicon wafer

Sure they are. But that doesn't prove your first sentence, since semiconductor diodes are constructed that way as well. Making a transistor on a semiconductor in that manner is no different than the process of doping an NP junction layer (a diode) followed by another N layer on top of the exposed P layer (which forms a PN junction, a reversed diode). Voila -- a transistor fabricated from two back-to-back diodes.

You *know* this, which is why you have proudly stated:

"Which, of course, makes my original statement, that a transistor was in a sense two diodes back-to-back, entirely correct."

So stop making an ass out of yourself by spending a week attacking *me* for (gasp) agreeing with you on that point. It not only makes you look foolish, it makes you look practically insane.

But hey, don't just take my word for it:

A transistor is formed by placing two diodes back to back in one piece of semiconductor material. This is done by layering N and P material in a sandwich A Brief Review of Transistor Theory

Bipolar Junction Transistors: There are two types of BJT -NPN & PNP – These devices are constructed of two diodes back to back Analog and Digital Electronics - ECET- 329

Transistors are sandwiches of three pieces of semiconductor material. A thin slice of n-type or p-type semiconductor is sandwiched between two layers of the opposite type. This gives two junctions rather than the one found in a diode. [one reversed with respect to the other -- Ich.] If the thin slice is n-type the transistor is called a p-n-p transistor, and if the thin slice is p-type it is called a n-p-n transistor. The middle layer is always called the base, and the outer two layers are called the collector and the emitter. We will consider the (more common) n-p-n transistor here, as used in the MadLab circuits. In a n-p-n transistor electrons are the main current carriers (because n-type material predominates). When no voltage is connected to the base then the transistor is equivalent to two diodes connected back to back. LESSON 4 - SEMICONDUCTORS

Now a transistor is merely a "sandwich" of these devices. A PNP transistor is depicted in figure 2 below. Actually it would be two p-layers with a "thin" n-layer in between. What we have here are two p-n diodes back to back. Transistors

A transistor, which lets the current from source to drain to be controlled by a gate, is a pair of diodes connected back to back. Since a transistor is made of two diodes, the next section will first describe what a diode does and how it works. Logic Diagrams to Transistors, December 10, 1993

BJT has two diodes back-to-back. Lecture 24 - PNP transistor

Bipolar Junction Transistors (BJT) - Consists of two diodes connected back-to-back. ICS217 - Digital Electronics

Question: I see a transistor is like two diodes back to back. How can current flow when one diode is always reversed biased? Answer: The short answer is simply that the two diodes are physically close enough together that they influence each other. The long answer is as follows. A junction diode consists of two regions of silicon-an N-type region doped with an impurity that has an extra electron relative to the silicon atom and a P-type region doped with an impurity that lacks an electron relative to silicon. [...] Now we're in a position to consider the transistor, which has three regions of semiconductor (N-P-N or P-N-P) forming two diode junctions back-to-back. The key to the transistor's operation is the fact that the center region (called the base from the days of the point-contact transistor) is very thin, putting the two diode junctions close together. www.chipcenter.com, THE ENGINEER'S TECH-HELP RESOURCE

Now, starting with the bipolar junction transistor (BJT) [...] A BJT comprises two back-to-back diodes, so you can double-check it with an ohmmeter. Troubleshooting at the component level: Understanding component functionality is paramount.

Bipolar junction transistors bipolar junction transistor, a bipolar transistor essentially consists of a pair of PN Junction Diodes that are joined back-to-back The Educational Encyclopedia, Electronic Components

A bipolar junction transistor consists of two back-to-back p-n junctions [a p-n junction is a diode -- Ich.], who share a thin common region with width, wB. Contacts are made to all three regions, the two outer regions called the emitter and collector and the middle region called the base. [...] Since the device consists of two back-to-back diodes, there are depletion regions between the quasi-neutral regions. Chapter 5: Bipolar Junction Transistors

Semiconductor Devices A # 50003: The physical structure of the Bipolar transistor as two back to back diodes. Courses of Aaron Peled, Professor of Electrical Engineering and Photonics

A transistor is two back-to-back diodes, that is alternating layers of either p-type/n-type/p-type (PNP) or n-type/p-type/n-type (NPN). The ‘closeness’ of the two diodes makes it unique, as electrons from one shoot into the other without resistance. Introduction to one of the most important inventions of the 20th Century

Now, are you going to stop trollishly spewing accusations against me of being a "liar" for stating the truth? Or are you going to keep being an a**hole?

Let's cut to the chase and see how fast you try to shift topics again, lest you be nailed down for a change. Is the following an accurate representation of a semiconductor diode, yes or no:

After we've settled *that* question we can move on to the next.

[balrog666]

Jellyfish... I mean placemarker.

[Ichneumon]

You don't have the requisite male anatomy to admit when you're wrong.

I admit when I'm wrong, but in this case I'm not. And your childishly making penis references does not constitute proof that I am. On the contrary, it makes it obvious you have nothing else to make your case with.

A battery is the source of potential dipstick, the base or gate of a transistor is an inherent component of same.

No s***, Sherlock. My point exactly. Now are you trolling, or just too stupid to see the parallel I set out for you?

Here it is in words small enough even for you: I described how a semiconductor sandwich of two PN junctions in serial (one reversed) constitutes a transistor. A PN junction, for those of you who get your knowledge from creationist sources, is a diode. Thus a transistor (BJT type, anyway) is formed from two back-to-back diodes. QED.

Then you came along and babbled incoherently about how there has to be a voltage applied to the base of the transistor or it won't work. I pointed out that this was a stupid "point" and in no way invalidated my statement about transistors. Your non sequitur, I pointed out, was as stupid as objecting to the workability of a radio just because it wouldn't do anything without a battery. Well sure, but who'd ever be stupid enough to insist on faulting a radio for not working without a power source? Likewise, what kind of gibbering twit is going to fault a transistor for "not working" unless power is applied to its base (and elsewhere)?

Are we clear *now*, child? Go away and play, the adults are talking.

I repeat, get a refund forthwith.

You can repeat all the cheap unsupported accusations you wish -- it only makes the paucity of your actual contribution to the subject entirely clear.

But if you want to make a stab at acting like a mature grownup for a change, feel free to read post 1763. Then either try to explain how all those other electronics articles are "wrong" also (they must be, since they say what I've said, right?), or take a stab at answering the question at the end. There will be a quiz later, and you *will* be graded on your answers.

[AndrewC]

After, saying we agree you now attempt to resurrect your lost argument.

Look, the fact that you do not understand the word "like" or understand the meaning of "in a sense" does not make your argument for you. Your links are peppered with words such as "like" or "essentially". Now your initial link states this in context.A transistor is formed by placing two diodes back to back in one piece of semiconductor material. This is done by layering N and P material in a sandwich (Figure 5). In reality a transistor etched into a die would look more like Figure 6.

Notice the author uses "in reality". Blather on, you are not getting anywhere.

I repeat I know that you can use a transistor as a diode in a pinch. After all, it "consists" of back-to-back diodes in a sense.

And you wrote ---Trollish Behavior #9: Not only "in a sense", Troll, but in actuality. Stop squirming, Troll.

[PatrickHenry]

PLACEMARKER

If you know what I mean. Wink, wink. Hee hee.

[null and void]

The secret is to file a shallow groove. As you get closer to the target value rotate the resistor slightly so you are not filing on the bottom of the groove but at a point on one end of the groove.

It does require a deft touch...

[AndrewC]

It does require a deft touch...

A 50 microgram touch on about a 2 watt resistor.

[null and void]

*shrug* I do micromachining for a living.

[AndrewC]

*shrug* I do micromachining for a living.

Using a file!?

[longshadow]

you could post to yourself, junior...

Yes, but then hair would grow on the palms of his hands and he'd go blind......

[null and void]

LOL! Not usualy. Using standard lithography and etching mostly.

Seriously, filing in a resistor value is something any lens grinder, diamond cutter or tool maker can learn to do.

Being willing to throw out scores of slightly too high value resistors helps...

[null and void]

I just did it until I needed glasses...

[donh]

"actuality" (his word) that a transistor was two diodes back-to-back. I replied that putting two diodes back-to-back did not make a transistor. I gave an actual example of soldering two diodes together,

...So, the question is, is "actuality" the physical black box called a diode by the manufacturers of potted devices, or is "actuality" what occurs on a silicon backplane where the active device actually does it's work?

Just for the record, this is, in your own words, the exact point in this conversation where your habitual jesuistry struck once again.

I will not respond to such a blithering idiot.

You already made and broke this promise once. Perhaps you have a 5 paragraph explanation as to why that didn't occur, as well?

[AndrewC]

Not usualy. Using standard lithography and etching mostly.

Well that is more like it.

[js1138]

Nice post Number placemarker.

[f.Christian]

Danger -- beware ... cyber-social virus on the FR --- mad science disease !

[AndrewC]

It was an accident. I knew it was coming up/

[balrog666]

If you know what I mean. Wink, wink. Hee hee.

Message received. Wolfpack formation on standby!