Talk:Transistor

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Oscar Heil

Is anyone aware of details of this claim about Dr Oscar Heil patenting the FET in germany in 1934?--Light current 17:03, 11 November 2005 (UTC)[reply]

Best I can do is this link JFETS: THE NEW FRONTIER wherein it states: "Field-effect transistors (FETs) have been around for a long time; in fact, they were invented, at least theoretically, before the bipolar transistors. The basic principle of the FET has been known since J.E. Lilienfeld’s US patent in 1930, and Oscar Heil described the possibility of controlling the resistance in a semiconducting material with an electric field in a British patent in 1935." DV8 2XL 18:28, 11 November 2005 (UTC)[reply]

Pictures

Does anyone have a copyright free picture(s) of transistors we could use at the top of the page to replace the rather grey looking one.?--Light current 17:25, 9 November 2005 (UTC)[reply]

Here are some more: commons:Category:Transistors — Omegatron 18:02, 9 November 2005 (UTC)[reply]

Replace lead pic with better one. This is still not a very good pic and we need a better one if we are to submit article as a featured article.--Light current 18:28, 9 November 2005 (UTC)[reply]

I added one I just took. --agr 20:43, 11 November 2005 (UTC)[reply]

Thanks. Thats better!--Light current 20:58, 11 November 2005 (UTC)[reply]

A picture of the 'chip' inside the transistor would be nice too.

Archiving

Previous contents of Talk:Transistor became too big, so moved to new page Talk: Transistor 1 (this page will be page 2) - CPES 04:38, 26 Apr 2005 (UTC)

Band gap

"The band gap is highly temperature dependent, decreasing with increasing temperature." part erased: the energy gap is always the same. What changes with temperature is the probability to cross the gap. User: 129.13.186.1

The above correction is from tran history and makes a very good point. I have read that the band gap varies with temperature. It also says this on Wiki band gap, so this needs to be sorted. I have changed the "Semiconductor material" sub section to cover this aspect. CPES 12:38, 25 Apr 2005 (UTC)

The band gap varies with temperature, but very little, and this is an almost insignificant contributor to changing conductivity. As stated above, the most significant factor is the ability of the carriers to cross the gap. Phil Holmes 15:34, 19 August 2005 (UTC)[reply]

Problems with part of 12.3 - development

Consider the following paragraph: "Brattain started working on building such a device, and tantalizing hints of amplification continued to appear as the team worked on the problem. One day the system would work and the next it wouldn't. In one instance a non-working system started working when placed in water. The two eventually developed a new branch of quantum mechanics known as surface physics to account for the behaviour."

It seems unclear to simply put in the term 'team' without specifying the team members & where they're working, as I see no mention of these things in the preceding paragraphs.. Later, "The two eventually developed... " - which two? Brattain & somebody, or 2 completely new somebodies? I'd like someone to write this paragraph more clearly, please. -- tharkun860 July 5, 2005 01:46 (UTC)

Stuff here and there and re-arrangement needed

Two types of transistors? I believe we do have a gazillion types of transistors these days. Perhaps we should accurately say, "in the beginning, there are two basic types of transistors, BJT and FET".

Looks like this article need some re-arranging. The types were described above (Semiconductor type, power ratings, etc), and then towards the bottom, we see BJT, FET, etc. They can probably live happily in one section. I am translating this page into wiki:id, I'm lucky as no one will protest the way I'm arranging the sections, heheheh... Kortsleting 03:23, 18 August 2005 (UTC)[reply]

Ending of initial paragraph is very inaccurate

It says "... allows a precise amount of current to flow through it from the circuit's voltage supply." I would recommend to replace "precise" with something like "substantial" or "significant". Using "precise" is completely wrong because in fact every individual transistor is very imprecise, and it's parameters vary widely from sample to sample, and with temperature. An electronic circuit can be made precise if a certain combination of transistors is used (like OA, operational amplifier) having high amplification but with a deep negative feedback loop. - apredtechenski, Sept 06, 2005

Agree. Ive changed it!--Light current 00:39, 21 September 2005 (UTC)[reply]

Put this page on a diet!

Just been trying to tidy the article and make it flow, but there is just too much stuff here that really needs to be elsewhere. For instance the history of semiconductors should go to the semiconductor page if there is one, detailed description of BJTs is already covered on BJT page. There is too much emphasis on FETs at the expense of BJTs etc. Can we have comments please on how this page can be slimmed down and be made an easier read?--Light current 00:47, 21 September 2005 (UTC)[reply]

I copied the semiconductor history stuff (its still here as well tho') over to semiconductor device which was a short article anyway, and I think the stuff looks good over there and fits in well. Have a look. If everyones happy, then we can delete that stuff from her as a start in tidy up operations.--Light current 01:36, 21 September 2005 (UTC)[reply]

Since there were no objections, I have deleted the large section 'History of semiconductor devices'. It can now be found on the semiconductor device page.--Light current 20:31, 25 September 2005 (UTC)[reply]

Opto FETs

I seem to remember that optically activated FETs are available. If so, this should be mentioned in the appropriate paragraph.--Light current 02:06, 4 October 2005 (UTC)[reply]

I don't know if discreet opto-FETs are available, but they're certainly available when packaged with an LED as an optical isolator.

Atlant 12:44, 4 October 2005 (UTC)[reply]

Yes thats what I meant. Thanks for confirming--Light current 23:31, 4 October 2005 (UTC)[reply]

Proportional current?

Im worried about the phrase 'allows a proportional current to flow'. In fact the current is not proportional to the voltage in a BJT but prop to the exp of the voltage. So this lead para needs rewording. Any suggestions?--Light current 01:09, 5 October 2005 (UTC)[reply]

I rewrote that sentence. Snafflekid 05:28, 5 October 2005 (UTC)[reply]

History section??

We used to have a history section that described where the name came from, etc. What happened to it?

Wait, don't tell me. Someone declared it "useless trivia" and deleted it. User:Omegatron/sig 04:21, 13 October 2005 (UTC)

Yes it was I who moved history to semiconductor devices after discussion and agreement I believe!--Light current 00:30, 14 October 2005 (UTC)[reply]

Not exactly. Semiconductor and Semiconductor device were to be merged. I did cleanup on the two pages. The history section of Transistor was moved to Semiconductor device, because Transistor was getting too long, as I recall. And, the "history of transistor development" involves more than transistors. I think that the history makes a good fit over there. Maybe it would be good, however, to add a very brief history section to Transistor with a link to Semiconductor device for more info, since I bet a lot of people will look here first for a history. Snafflekid 18:49, 13 October 2005 (UTC)[reply]

Removed from page

All This stuff has been removed from the page because: A) This text is not about transistors B) page is about transitors and not transitor amplifiers. C) page is not about audiophiles or how transistors sound

Some argue that the larger number of electrons flowing in a vacuum tube behave with greater statistical accuracy, although this ignores the fact that vacuum tubes generally have a high-impedance control terminal (grid), and that discrete transistor circuits (as opposed to integrated circuits) can also be designed to use large currents.

Others detect a distinctive "warmth" to the sound. The "warmth" is actually distortion caused by the vacuum tubes, which some audiophiles find pleasing. This is "soft-saturation" which occurs when vacuum tubes are overdriven, causing poorly designed vacuum tube amplifiers to sound better than poorly designed transistor amplifiers. Tube amplifiers are also less prone to slew-rate limiting, which was a problem with early semiconductors and is still observed in low-cost transistor audio amplifiers.

Above speculative opinion gives no correlation between characteristics or measurements and perceived sound quality. See Tubes vs. Transistors - Is There An Audible Difference? and Transistors vs. Tubes - Brief Feature Comparison.

Vacuum tubes are also preferred in guitar amplifiers which are designed to be overdriven, because they have a different non-linear transfer characteristic than transistors, and create a different, more pleasing spectrum of harmonic distortion or "fuzz". Digital signal processing (DSP) can be used to achieve similar effects in the digital domain.

(single-ended transformer coupled to push-pull transformer coupled to push-pull capacitor coupled to push-pull direct coupled). DSP Recently, inroads have been made in digital signal processing (DSP). DSP is a technique that can (among other things) be used with A/D and D/A converters to allow a digital processor (along with a computer program) to manipulate analog signals.

I totally agree that this stuff does not belong here. I didn't have the energy to start a new page at the time. :) Snafflekid 02:11, 14 October 2005 (UTC)[reply]

If its to go anywhere, it should go to audio amplifiers or electronic amplifiers--Light current 00:50, 14 October 2005 (UTC)[reply]

It most definitely "goes somewhere". Deleting large chunks of information is not helpful to anyone. Yeah, it's still in the history, but it should be in an article, and people generally don't go digging around in the history unless they are looking for something specific.
Better places to put it would be Tubes vs transistors, Valve sound, or Audiophile.
When something is moved from a general article into a more specific article like this, there should still be a short summary in the main article with a link, to keep the articles tied together. This is definitely relevant enough to the transistor article to get a sentence or two and a link. User:Omegatron/sig 01:58, 14 October 2005 (UTC)

I try to delete as rarely as possible. At bare minimum it is better to move it to an new page or even cut and paste the unwanted stuff onto a new wikipage and let someone else edit it IMHO. Snafflekid 02:09, 14 October 2005 (UTC)[reply]

Moving to the talk page is a very good alternative to deleting it, too. User:Omegatron/sig 02:15, 14 October 2005 (UTC)

Im not sure if you are telling me off here 'O'. Have I done something wrong IYO?--Light current 02:21, 14 October 2005 (UTC)[reply]

Unweildiness - is that a word?

Page is starting to get too big again with addition of lots of stuff thats not strictly relevant and that could go in other pages. Please be carefeul about whats added to this page.

"There is no need for haste." See Wikipedia:Article size. User:Omegatron/sig 01:50, 14 October 2005 (UTC)

32kB is just a suggestion, but a good suggestion. However, transistor has a very big field to cover. Snafflekid 02:04, 14 October 2005 (UTC)[reply]

Not Fair

sorry! I forgot bout the size of page. now, i have provided links to images. but dont u think that we are not doing justice with transistors; comparing the vastness of the capacitor page and this page :) .we must include many concepts like Ebers Moll Models, Π -model, h-model, etc. or if these are already present, dont u think that they should be merged? --Davy Jones 04:37, 16 October 2005 (UTC)[reply]

Heh, well you could create new pages for each of those concepts and link them into Transistor. BTW, did you ever find your locker? Snafflekid 06:37, 16 October 2005 (UTC)[reply]

Define your terms

The terms "base" "emitter" and "collector" are introduced without description.

Transistron

The Wikimedia Help Desk received advice from an expert in the field that the article in IEEE Spectrum How Europe missed the Transistor contains considerable errors which have been placed in the Wikipedia article. The IEEE apparently has been asked to correct the record:

Specifically, the informed source says:

"Your page about transistors contains an abstract of the Spectrum article and should be reviewed as follows: The correct term is "transistron". The French "Compagnie des Freins et Signaux Westinghouse" was not a subsidiary of Westinghouse Electric. The amplifier developed by Welker and Mataré was not a point contact device. It was based on the minority carrier injection process."

Capitalistroadster 07:33, 6 December 2005 (UTC)[reply]

The mistakes are not the IEEEs but mine; though the transistron (correct spelling) did have point contacts and all bipolar transistors rely on minority carriers. The French company must at least have been an affilate of the Westinghouse (railway) brake company. --Wtshymanski 03:47, 8 December 2005 (UTC)[reply]

Transistor biasing-The most basic question

Why is the base-emitter junvtion of the transistor forword biased and the collector-base junction reverse biased?Why not the other way round?

If the BJT is used in the forward active mode (which is almost always the case) the collector voltage is higher than the base voltage and the base voltage is higher than the emitter voltage. For an N-P-N you get the condition you mentioned. If the collector is pulled low enough it will become forward biased also, this is called saturation. Snafflekid 17:22, 8 December 2005 (UTC)[reply]