Added: 3 years ago
From: dizzo95
Views: 321,756
Sort by time | Sort by thread (beta)

Link to this comment:

Share to:

All Comments (165)

Sign In or Sign Up now to post a comment!
  • How does applying a positive current to the base allow conduction? Isn't there still a negative charge on the collector that would repel any incoming electrons?

  • So how would you go about applying positive current to the base?

  • I like this video, good job! There is just one inaccuracy though - phosphorus is used to create N-Type Material. Adding Boron will not create N-Type Material, but P-Type material. An N-Type semiconductor has extra electrons. Phosphorus has 5 valence and silicon has 4. They add up to 9, but only need 8. So there is a free one that can move. Boron only has 3 valence electrons so when it combines with silicon it takes one to create a hole in the silicon.

  • 240p we meet again :)

  • So does it increase amp for sounds or can you use it for powering stuff too, if that the case then couldn't i make one 9v battery give out 200% power using this ?

  • too simple for who could undertand the video and too complicate for who needs this information.

  • 341 people reached here only for passing time..

  • 54 people failed in physics last year..

  • This animation is misleading.

    For simplicity, a transistor is a three terminal device. One terminal is used for control, and the other two terminals are used for current entry and exit.

  • @blackstar2008 oh really..??

  • @naveedlahoriable Ok, think of it this way:

    A transistor is either an amplifier or a switch.

    It's an amplifier when it's used in its linear range. Applications like audio circuits.

    It's a switch when it's used in its non-linear range. Applications like microprocessor circuits.

    As an engineer that's all I need to know :)

  • @blackstar2008 Thank u very much..!!

  • ok im a begginer .... whats the difference between a positive and negative current ????

  • Ok so if i apply 10v through a transistor, it will give me an amplified voltage at the emitter?

  • Your voice sounds like you've got a transistor in your vocal cord. lol!

  • Comment removed

  • 0:49 N-type and P-type materials are NEUTRAL. They are neither positive nor negative. In the case of N-type, the surplus of electrons are donated by impurities (like Phosphorus) and these impurities become positive Ions. So the net charge is always zero.

  • My year 12 physics teacher put this video and others on my USB to take home and watch, but we don't have the program to watch them on our computer. Thanks for putting this one on youtube so I can actually study

  • Comment removed

  • If transistors were just NPN layers like this you could just put two diodes together and make a transistor however if you see how the very first transistor was made you will see that the base is large and at the bottom and the emiter and collector are seperated by a small gap on the top of the semiconductor crystal.

  • yes, what is a "positive current" ?

  • @8clutchG positive current refers to the conventional current.

    we know that the positive and negative charges move in opposite direction. If negative charge moves from negative terminal of the battery (cathode) towards positive terminal (anode),it is expained that an opposite charge moves in the oppsite direction i.e. from anode to the cathode.

  • Positive current Negative Current ? What da hell ? There is only one current, is not it ?

  • Yeah, sorry--you made several mistakes here. Phosphorus is used for N-type doping, Boron is for P-type doping. Also in an NPN transistor, the Collector is the input and the emitter is the output, not the other way around (hence the names).

  • I kinda get it, plz keep the labelling while explaining.

  • boron is P-type !! phosphorus is N-type !!!!

  • @MineAurora no!!!!

    

  • at 1.10 , the input layer is collector !! the output layer is emitter !!! please check again thx ....

  • Comment removed

  • I have no idea, could not figure out how they work in ten million years I guess I am just a dumbass

  • everything that starts from 1:29 i dont understand.

  • @veryfuck watch the vaginal childbirth video on the right..you will get it

  • @veryfuck

    haha exact same here mate :(

  • Stupid video, p-type material is made of borons and n-type materials is made of phosphorous. Take down the video and get it right.

  • I understand the transistor in a standalone circuit, an LC oscillator separately as well but I never truly understand how they are connected together with many feedbacks etc.

    If someone could make an animation where one could see all values of E,R,I for all components for every t0,t1,t2,... in a cycle.

  • lol....emitter is output..

  • vaginal childbirth?

  • @raileanulucian lol, I just saw that, was about to make a comment, and see someone beat me to it

  • this is actually one of the better transistor explanations.. u dont want the explanations i was getting in college lol

  • what is the driving force for the electrons from n type to jump on p type at juction in p-n junction diode? (aka reason).

  • WOW this demo is sooooo wrong... at the end the animation shows a NPN transistor and they say adding more current to the base will allow more current to flow from the emitter to the collector but in an NPN transistor current flows from the collector to the emitter.... Does any one agree with me????

  • Comment removed

  • The graphics near the end incorrectly show the collector current as being larger than the emitter current. In fact, the emitter current is always larger than the collector current (Kirchoff's Current Law). Amplification occurs between the base and collector currents. Example: 100 mA enters the emitter, 1 mA of that current flows out of the base, and the remaining 99 mA continues out the collector. We say that the 1-mA base current (the "control" current) has been amplified 99 times.

  • @rchandos Nice !

    'Think I got it !..

  • SO COOL. Thank you for giving a real explanation of the thing you are talking about, this is becoming scarce. I feel that I understand why the transistor is so powerful, but not the mathematical roots of its action.

  • This is so confusing...someone made this sh** up :P

  • So the current gets 100 times greater....wonder where does all this extra charge come from. From the additonal wire to the base? Kirchhoff's law seems broken to me. Explain please.

  • @DarkLevis hi dude i also have the same confusion ..... but when i asked by professor ... he replied the current at the collector end is actually a larger "IMAGE" of the current flowing throw the emitter ..... nothing really get's amplified , it's just like a man standing in sunlight when sun is about to set and the shadow of man appear to be larger because of a lower angle of incidence ........ but i m still confused how can u increase the current without "INDUCTION" or "GENERATION"

  • I still don't understand how I'm suppose to wire a transistor. Anyone know where negative goes? Where positive goes? 3V batt good enough?

  • I read so many German (my first language) descriptions and I wasn't able to understand anything. Then I watched this video and I understood everything instead.

  • Comment removed

  • Uh. No. Phosphorus has 5 electrons in it's valence shell. This contributes an extra conducting electron to the Si structure. Phosphorus doped creates N-TYPE Si. Boron doping, which has one LESS electron, gives you P-TYPE. I had to go back. I thought I misheard this. Thumbs down, man.

  • @HuggumsMcgehee yeah just about to say that, now i dont know whether to trust anything in the fucking video.

  • @HuggumsMcgehee its valence shell*

  • Whether one should take conventional current or electronic current when analyzing a transistor?

  • mmmm.... transistor sandwich...

  • Also I thought current flows out of the emitter... Unless narrator means positive charges flows into emitter terminal.

  • What I couldn't understand for 4 hours due to my useless books and its jargon I understood in 2 minutes.

  • Electricity will flow where ever there is the greatest potential (voltage) and it can flow either way. But we use convectional current in electronics just to simplify things. In reality it flows from negative to positive. So if I have -30 volts and -90 volts current would flow from the -90 volts to -30 volts because -30 is more positive value than -90 volts. Remember voltages is really EMF. Think of this as dynamics like in mechanical physics.

  • This video is horrible. And he got it backwards: adding an element with 3 valence electrons like boron creates a P-type semiconductor; adding an element with 5 valence electrons, like phosphorus, creates an N-type semiconductor. Silicon has 4 valence electrons, so when a boron atom is incorporated into the crystalline lattice, it creates a positive charge carrier called an electron hole, whereas when a phosphorus atom is incorporated into the lattice, it creates an extra wandering electron.

  • Video is misleading :at 0:42 should be vice versa

  • Trying to understand how a transistor works is turning out to be an exercise in futility. I'm not a dumb guy (or so I thought), but every new explanation I see just makes me more confused! So far the clearest one I've found is on the Nobel Prize web site, but even that is lacking. The one on How Stuff Works is pretty horrible. If someone knows of a good book/site/whatever, please let me know! Thx!

  • i dont uderstand how if there is a current going into this diagram from left to right.

    shouldnt the electrons be going from right to left? because conventional current is opposite to the flow of electrons. i am confused

  • allenhollister dot com slash allen slash files slash  physics dot pdf

    a good website :P

  • it doesn't explain any of the solid state physics but gives a superficial introduction.

    I don't like how they depict current on the collector as an open circuit. no respect for kirchhoff's law

  • Yeah, what's up with this video? they got it backwards. Phosphorus is N-type and Boron is P-type...

    TAKE THE VIDEO DOWN or FIX IT

  • The video is wrong!

    P: surplus electron: N-Type

    B: lack of electron: P-Type

  • my head is spinning.. im just happy there are some people who get this, so i can keep making stupid comments on youtube

  • This is very misguiding.

  • SEE THIS:

    Turn Radio into Guitar Amp:

    youtube.com/watch?v=YHfoON7ukS­c

  • My professor is killing me with all those transistors we were learning just about them for like 3 months I am getting a headache O_O

  • Thanks for this video. i am learning about electronic science.

  • Despite the critics the vid. does well to illustrated what is happening inside the transistor. Not mentioning the doping materials might have satisfied the critics, but I doubt it. Those without a solid base in electricity/electronics will never get how solid state devices, or even electron tubes work, I fear.

  • Comment removed

  • your video on how transistors work has things totally the wrong way around.

    N-type conductors consist of arsenic or phosphorus etc, not boron!

    Doesn't make sense at all, boron is trivalent.

    P-type conductors consist of boron or indium etc, not phosphorus!

    Again, doesn't make sense, phosphorus is pentavalent.

    Secondly, the input is not called the emitter, it is called the collector and

    the output is called the emitter and not the collector.

    Is this some sort of prank video?

  • @davidswords Ha ha! I was just going to make the same comment (more or less). I have been teaching transistor theory for 30 years and I had to double-check myself that Boron=P and Phosphorus=N! LOL

  • @davidswords Ha ha! I was just going to make the same comment (more or less). I have been teaching transistor theory for 30 years and I had to double-check myself that Boron=P and Phosphorus=N! @:42 LOL

  • please tell me how transistor works?

  • Great production value and I like the energy in the way you present the information.

  • these words are going into my head and right out. i still dont get how to wire it to a circuit. i wish someone would actually SHOW them wiring one of these up.

  • I still dont understand how the signal is getting powerfull, i mean what causes the signal to be more powerfull? And why?

  • @iamsnail

    Why it happends that when the control layer gets the weak signal to it and it changes the electrical qualities of that, by creating more hole, then why after this the weak signal get more powerfull?

  • @iamsnail The amplification of the weak signal happens because once current begins flowing through the emitter-base junction, the base allows a much larger current to flow between emitter and collector. This ratio of emitter-collector current to emitter-base varies among transistors but ranges from about 10 to1 to several hundred to1. Assuming this ratio is 100/1, a current of

    1 microampere in the base-emitter junction will cause 100 microamps to flow

    emitter to collector.

  • @iamsnail The actual signal into the transistor is itself not made any more powerful. The input signal through the base-emitter junction varies the separate and much larger current through the emitter-collector junction.  The emitter-collector current is a much larger replica of the base emitter current.

    It's like your hand on the throttle of a big diesel engine. Your hand uses a small amount of force to move the throttle. The engine makes a large force that your hand controls.

  • This explanation contains a hole: The conductivity from the emitter to collector depends on the VOLTAGE at the base; there is no CURRENT flowing through the base. But if no current is flowing through the base, there can be no more and no less "positive holes" in the base. So, how does a transistor really work?

  • @humandimm There are 2 main 'types' of transistors: BJTs and MOSFETs. This particular type is a Bipolar Junction Transistor. (assuming a NPN transistor) When conducting, Vb is > Ve, and a current flows from base to emitter. In this type of transistor the current through collector to emitter is controlled by the base emitter current. When talking about BJTs, you need to be thinking current.

    The other type, MOSFETs, does not have current flowing into the gate - which is analogous to the base.

  • Disregard all information.

    This is either a joke or should be removed from you tube.

    Everything is reversed...

    "emitters" do not input

    "collectors" do not output...

    etc..

  • well not everything, just most things so it will confuse you and hurt you down the road

  • Why would the "emitter" be the "input", and the "collector" be the "output"

    everything else makes sense.

  • The Emitter & Collector can be either in or out depending if NPN or PNP. The names can be misleading as a result. .Conventional current is + to - {the early geeks were incorrect} but electron flow is now known to be - to +.

    Most electrical diagrams still show conventional flow which further adds to the confusion.

    The original guys got a Nobel prize ...I now know why :)

  • @jpgold21 Not everything else makes sense, the N-type conductors are doped with boron and P-type with Phosphorus it says, it should be the other way around too.

  • i'm not understanding everything here

    first, are they saying that the if the p type has x holes in it, then x electrons can flow from emitter to base, and from base to collector per unit of time, but if it has 2x holes in it, then 2x electrons can flow from emitter to base and base to collector in the same time?

    and 2nd, how does applying a current to the base increase the number of holes? shouldn't pushing electrons into the p side fill more holes?

  • There is a mistake, N type materials are made with phosphorous.

  • what do you get if one builds a 30 foot diameter transistor?

  • the explanation is hard, this video doesn't really explain anything why the stuff in the transistor happens, and how to increase the current of the colector by changing the voltage in the base you need another battery connected to the colector to allow the electrons from the emitter flow to the base and then the collector.

  • Hmm, it seems the base-emitter voltage follows a logarithmic pattern as a function of current. Using them in the feedback loop of an operational amplifier can prove quite useful for analog multiplication. If anyone is intersted, then feel free to google the Schottky Diode Equation :).

  • thanks a lot ..graziee

  • phosphorous makes N, boron makes P. the video messed these up.

  • good job but i wish you would have kept the base emitter collecter labled

  • @j1crx Pause the vid when it is shown, do a screen save then paste into a graphics editor like MS paint and save as jpg.

    Jp

  • good job. the way how a transistor works is understandable for those that don't know the basics of electronics...

  • Pokemon ? in Transistor ? What dont they have a job anymore ? lol anyways the vid was good & really usefull for me :)

  • does not compute lol

  • what the fuck is he saying?

  • Excelent at last someone explain how a transistor works in a understandable way uffff

  • youre kidding right?

  • For me Its okey, I´m a electronic´s world beginner, but if you have a better video o any web address where I could get more explicit information, I would appreciated. for free...

  • Id just read it somewhere. The maker of this video could do better by first explaining what a diode is and how it works, and then explain the transistor.

  • You are right somehow, but you can´t understand how a transistor works if you don´t even know what a diode is. It,s simple, you first creep then walk. Isn´t it?

  • Yes, that is the way I see it.

  • OMG this guy sounds like the voice that comes from the Pokédex!

  • Not a very good explanation. I'd prefer something which goes down to the atoms. Explains the depletion zone, the electric fields and so on. Time to make my own video.

  • it's not really an amplifier. It just acts as one. It's really a valve. The small voltage opens the valve to a certain degree, allowing the large current to flow. The more the small voltage is increased, the more current is allowed to flow.

  • omg this makes no SENSE!

  • I know what a transistor does but no videos on youtube have explained thoroughly how it works in full detail, i mean i dont have much knowledge with circuits and knowledge, so wtf IS a base, collector and emitter!!

    I know the basics about current, voltage, resistance and electrons , but how am i supposed to understand this anyone can simplify?

  • @DarkForgottenUchiha the collector collects the incoming electrons, the base allows for more electrons to group in with the current thus increasing it. the emitter the emit or expels out the increased current

  • wow thanks i get it now :)

  • @jazzyjmay85

    Other way around, buddy.

    It's just called the collector/emitter, because we tend to think of electricity with hole-flow.

    Really, the electrons are moving from negative to positive, or emitter - collector.

  • Comment removed

  • OK. So where does the Base current come from in an IGBT inverter? Anybody know?

  • You have the dopants reversed!

    Boron = P type

    Phosphorous = N type

    Also the current flowing in to the emmitter is equal to the collector current minus the base current --- your image is way out of scale

  • nice but i still didnt understand one bit.

  • weylin6

    the emitter is heavily doped and the collector is lightly doped, a transistor CAN work if you cross the collector and the emitter but not very well

  • 6th video, still dont get it...

  • Comment removed

  • @holm79 read...go to allaboutcircuits * com  and look under semiconductors.

  • @holm79

    You are not alone. It took me 12 years to finally understand it... /:

  • @holm79 i have an exam tomorrow, my last chance to get it or else i am screwed >.<

  • @holm79 its like a switch when you give electrity it will pass electricity from the outher 2 pins

  • Very helpful. Thanks!

  • Every transistor explanation I ever see is incorrect, confusing, and uninformative...

    What's the difference between the Collector and Emitter? Doping %? Surface area on the Gate? Can the Emitter and Collector be reversed in a circuit, or will this damage it? If so, why?

    One thing I want to say is that transistors work on the Emitter-Base VOLTAGE controlling the thickness of the depletion layer between where the two P & N layers meet. When the depletion layer is thin enough, charge can flow.

  • There are some circuits which intentionally reverse the collector and emitter of a bipolar transistor. For most types of transistors, the result is a very low current gain and breakdown voltage.

  • When are transistors connected in reverse, for what purpose?

    Only time I ever connected a transistor backwards was when I was making a "white noise" generator, but I only needed the Base and Emitter connections.

  • I have seen some audio distortion devices that use reversed collecter-emitter circuits. And as someone commented to me, you can use a reverse-biased base-emitter junction as a pretty good Zener diode.

  • I remember a few years back, I discovered that using a high resistance/high voltage reversed biased emitter-base setup, it created a very clear hissing sound, even without amplification.

    I used 9 volts, and something like a 300K resistor, and an NPN bipolar transistor.

  • Try to understand first how a diode works, that is going to make you easier to understand how a transistor works

  • Well I was going to say something to this effect, except I don't take physics.

    Like most everything practical this is just a model of how it might work. The fact is that it works, and it has certain behaviours, but the explanations behind those behaviours may well turn out to be incorrect.

    It only becomes important to know how something really works when you want to improve it. So I'm guessing they're going to have a fun time getting nano-electrical components to work properly.

  • @weylin6 Are you talking BJT or FET? There is no gate in a BJT. The principles of operation between the 2 are totally different. If you are talking NPN, and if I remember correctly, the emitter is much smaller than the collector, but the base is much thinner. The actual dimensions and doping values vary greatly between devices. The emitter and collector cannot usually be reversed. In some discrete FETs the source and drain can be, but it's not common.

  • @ikedasquid I should have been more specific, I do mean the BJT type since they do work on two totally different mechanics.

    When they show a diagram of, say, an NPN transistor, they show it as a 3 layer sandwich, and It was never explained how the emitter and collector differ in structure.

    I tried connecting the base and collector of a transistor in reverse bias once, using a 9v battery and 300k resistor, and found it to make a very audible white noise, even without amplification. 

  • Comment removed

  • test:

  • test

  • In electronics, a transistor is a semiconductor device commonly used to amplify or switch electronic signals. A transistor is made of a solid piece of a semiconductor material, with at least three terminals for connection to an external circuit. A voltage or current applied to one pair of the transistor's terminals changes the current flowing through another pair of terminals.

  • Thermionic emission

    & Richardson's Law

    and thorium plated filiments: " Thermionic currents can be increased by decreasing the work function. This often-desired goal can be achieved by applying various oxide coatings to the wire. " wherein plating vacuum tube cathodes with thorium increase the electron emissions 1000x - if the electrons flow to the copper anode to wire output - why wouldn't this save us a lot on our electric bill ? ( a nuclear power station in a vacuum tube ? )

  • Boron (III-material) ----> P-type

    Phosphorous (V material) -----> N-type

  • thank youuuuuuuuuuuuuuuuuuuuuuuuuu..­....I'm italian and these american or english documentaries are very usefullllll !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!­!!!!

  • PLZ HELP!!! l0st

  • YouTube will be undergoing scheduled maintenance, starting around 7:00 pm PDT.

  • very good!

  • thanx...........superb video.

  • nice

  • You are a saint for posting this. Thank you so much.

  • Audio description OK, but arrows deceiving. Shows much more collector current than emitter current.. The arrows on the ends should be the same size, with a small arrow coming out of the base. Voltage polarities should also be explained.

  • Now i understand

  • i still dont understand this and how they work plz help

  • Very Helpful

  • Excellent video for Beginners

  • Thanks alot, what a great video. Really useful fast demonstration.

  • Thank you so much for posting...it is very helpful

Loading...
Alert icon
0 / 00Unsaved Playlist Return to active list
    1. Your queue is empty. Add videos to your queue using this button:
      or sign in to load a different list.
    Loading...Loading...Saving...
    • Clear all videos from this list
    • Learn more