NPN vs. PNP Transistors as Common-Emitter Switches

[@HellaFunnyShorts]

One of the best, simplest, and most straight-to-the-point demonstrations I've seen. Obviously excluding the backwards battery

[@kevpatt]

Thanks!

[@madamerotten]

I don't want to seem negative, but I am positive that your battery symbol is reversed.

[@kevpatt]

+madamerotten yup... a sketch drawn in haste and then turned around... I will apparently never live this one down. :(

[@laggeroomaepiclagger2454]

3 GUARD

[@nick54thegreat]

Doe!

[@stormshockin]

I actually disagree.. since power seems to actually work from neg to positive. And not from pos to neg. I think it is more accurate this way.

[@nick54thegreat]

he has the Positive terminal of the battery connected to the ground symbol, and has labelled it negative, while the negative terminal of the battery is labelled positive.

[@mikecatlapp5775]

That was the best description of NPN vs PNP I have seen

[@kevpatt]

+Mike Catlapp Awesome, glad it could be of help!

[@BillAnt]

Not sure if it was mentioned, that PNP transistors are commonly used in audio power amplifiers as a complementary pair on the output end, working in a push/pull configuration of the signal.

[@MarkWarbington]

Watched ten transistor videos before this one. Yours was the best. Excellent job!

[@kevpatt]

+Mark Warbington Thanks!

[@radostar7139]

Agree

[@wakefieldyorkshire]

Yup I second that.

[@rayhantec4833]

I agree too

[@electronicstuff6355]

Me fourth

[@MrMac5150]

Nobody but you, made it easy to understand, I could never understand, the shunt effect. good video, I hope you have one on Mosfets. Thanks.

[@kevpatt]

MrMac5150 Thanks! Yes, I will be posting more videos on mosfets and other components.

[@MrMac5150]

Kevin Patterson You have got my attention on your channel, it is excellent.

[@kevpatt]

Glad to have you. Thanks!

[@PhilJonesIII]

Five vids in and you are the one that nailed it. One guy even showed how to wire an NPN when he was in fact using a PNP......confusing as hell. I was following along on my breadboard. Nice video, clear explanation. Keep it up.

[@kevpatt]

Thanks! Glad it was helpful!

[@markybogbrushify]

agreed! video eeds more votes!!

[@DupczacyBawol]

Theres 80% of idiots who pretend to know and understand and 15% of those who intentionally upload the Internet with false information and knowledge.

[@luvradios]

As an Electronics technician for the last 25 years, my job primarily has been to troubleshoot why something isn’t working, having a basic understanding of electronics principles and experience with tons of failure scenarios has served me well. Scrolling through the videos on here today I found yours to be the only one that brilliantly and simply explained transistors, I loved the imaginary jumper explanation of how the transistor works as a switch. When troubleshooting any electronic device the first rule is simplicity! Example - if your receivers FM band isn’t working doubtful you’ll find the problem in the amp section. Well done sir!

[@marko5472]

This really helped me understand transistors better than any other videos I have seen. When the teacher is good, also difficult things are easier to grasp.

[@taneliharkonen2463]

This was THE best explanation of the npn/pnp transistors! Subscribed! :D

[@kevpatt]

Thanks!

[@SergeyRyabenko]

Thank you Kevin! This is the most concise yet probably the best explanation I've seen about the topic.

[@amirrezafiroozi4080]

Hands on one of the best explanations available on transistors! Keep up the good work!

[@BobSmith-bv9ep]

Finally. Not even nine minutes long and I can actually get it . Why can't they all be this simple? I was seriously becoming convinced that an easy explanation was not out there. Subscribed.

[@kevpatt]

Thanks! Glad it was helpful!

[@SpeakerBuilder]

This is the best and clearest description of the switching function of transistors I have seen, very well explained, thanks.

[@kevpatt]

Awesome, glad you found it helpful!

[@wtfucrazy]

Simple, to the point and not losing yourself in details. Good job.

[@mingdeli8124]

Perfectly explained the difference between PNP and NPN !! I have searched more than 10 videos and no one is better than this one !!! Thank you!

[@kevpatt]

Awesome, thanks!

[@yoramalon5273]

I subscribe to this channel , because this man has a unique gift. He explains things in the most easiest way to understand, in the most easiest conotation, in the most simple way. He does it slowly and explicitly. This is the best teacher i have seen on youtube.

[@captbullsnort]

The very best explanation and video I have ever seen on transistors. They have always been confusing to me. I never thought anyone could explain these silly little devices in a clear and simple way. YOU DID AND YOU NAILED IT.

[@maxwarfield6699]

Finally! NPN transistors and PNP explained, in a COMPREHENSIBLE manner, for complete NOOBS like me. Been looking all over the web and all I came across was a bunch of FAST talking know-it-alls preaching to the already converted. Kudos and THANK YOU good sir, for this great video. Cheers!

[@kevpatt]

You're welcome! Glad it was helpful.

[@boshboshish]

I swear, you have explained the transistor basics more and way better than when I took it back in school.

[@GreatWhiteNiko]

Not sure that you realize - by this time (May 2019) your video is the best on KZbin explaining how a PNP transistor works. You don't explain how the electrons flow inside the PNP transistor but providing that one knows how the electrons flow inside a NPN transistor (plenty of videos about that on KZbin) and from all the other details that you clarify it becomes obvious how the flow of electricity from Emitter to Base allows the PNP transistor depletion zones to open up for higher current flow. Thank you very much!

[@captainprototype187]

@GreatWhiteNiko. You know about this stuff. Does the base need current or just voltage? I am trying to make my first pulse motor which is like the HOLY GRALE for me.. The base gets its jolt from spinnin the rotor (with magnets attached) near a coil. The NPN opens and lets trough a big puls of current to magnitise the coil. This pulse of magnetism pushes the rotor along. I think I got the theory down but in practice.....

[@GreatWhiteNiko]

@@captainprototype187 Oh no, don't get me wrong. I am just starting to learn electronics. So far I'm at the level of "how it works" but literally nothing practical. You need to ask someone else. Your question makes me wonder too - does the base need amps and voltage or just some so-so voltage?

[@captainprototype187]

@GreatWhitwNiko. Lol, you sure sounded like an expert! I think I got the answer now. The npn has 2 circuits built in. The first, trigger, circuit activates the bigger circuit. So you put the positive lead on the base and the negative goes to ground. That makes the first circuit. And every circuit draws a current. Furthermore, every vid calls the transistor a current drawing device. I found this vid that helped me a lot. kzbin.info/www/bejne/oX-5knynorCIpas

[@GreatWhiteNiko]

@@captainprototype187 Well, today I asked a friend of mine that is an electronics guru about the very basics of transistor use. What he told me was unexpected for me. See if you learn something practical too: 1. Bipolar (PNP and NPN) are used to REGULATE current. Used to control motor speed for example. 2. FETs (MOSFET) are used as switches - just turn on/off the current. Not sure in what applications they are used most. I see them in TV circuit boards all the time. If they are used as switches it'd make sense to assume that FETs are used in computer chips but I apparently speculate here. Also: 1. Bipolar - the gate uses CURRENT - From 0 up to 0.7A. You vary the current (Amps) of the gate and the big current from Emmiter (Source) to Collector (Drain) varies with it. 2. FETs (MOSFETs) the gate use VOLTAGE. Because what you want is to "pressure" up the area that creates the magnetic field which "opens" the flow of current from Emitter to Collector. And FETs basically work like that - you supply voltage and they do nothing. You increase the voltage and they still do nothing. Then at some point they let all the current flow. So that's a "digital" type of operation - 0 or 1 - closed or open. That's why they are used as switches. My friend also said that all the details about electrons/holes, and depletion zones are not needed at all when you actually work with electronics. The movement of electrons etc are good to know and cool to know but once you start practically using the components that goes way way in the background. But to me it is about feeling confident about my knowledge so I like to learn stuff like that. Good luck.

[@captainprototype187]

Thanks. some new info here. I will concentrate only on npns. Making a working circuit is hard you will find. It is for me, anyway.

[@JamesKelly89]

What really blew my mind about this video is that I never thought of transistors as actually being two different circuits. I think I understand them far better than ever before now!

[@kevpatt]

Glad it was helpful!

[@paulb8264]

Even with the battery symbol slip (didn't notice till I read some comments) the walk through of the concept was extremely useful and well explained. Thank you very much for this video.

[@prakashq2020]

I have watched so many videos, I name it BY-FAR THE BEST.

[@stevetrout1275]

The best explanation of these transistors that I've EVER seen! Keep up your good work.

[@kevpatt]

Thanks!

[@844pm2]

Thanks Kevin, I've see through many videos about the transistor, their explanation are complicated but you're making it easier for people to understand

[@kevpatt]

+Forever Joy Thanks!

[@chapinoable]

Of all videos I've watched about transistors, your video made understand it better. Thank You

[@nickbungus]

Thank you, thank you. Finally, an explanation on how to use transistors and not how they work internally.

[@kevpatt]

+Nick James Thanks, and you're welcome!

[@enriquesalgadoaceves9017]

dude, I went through at least 50 vids trying to understand, I got a basic idea, but you my friend, youuuu, your voice is clear, its smooth and easy to.listen to, its sound is just right, your pauses are perfect while explaining, the mellowness helps, and within all that the overall explanation of the how hard it is for us noobs, you make it sooooo much easier my friend, you get unlimited lifetime likes and promoted to my diy buddies thank you GB..

[@enriquesalgadoaceves9017]

having said that I'm still learning on how to.make it work with my project, I'm trying to make a solar lamp, I'm using a 3.7v lithium ion battery , 2400mah. I have my light dependant resistor which I think its around 15ohms, and my load (LEDs) will vary, my problem is to find an easy formula to calculate what resistor will I need to work with each individual led or small 6v hylogen lamps, if you can point me in the right direction I would appreciate it

[@ElTurbandito]

it is so sad I am paying for university but have to go to youtube to get a professor who doesn't just spew formulae and actually explains the concepts. Thanks for the concise explanation.

[@kevpatt]

You're welcome! Hopefully things will become clearer as you get a handle on the basics. Good luck!

[@zanecook4402]

This is the best explanation of PNP vs NPN transistors I have come across.

[@tonyrebeiro]

Except for the battery symbol being flipped, the explanation is Very clear and easily understood.

[@kevpatt]

Thanks!

[@khordad1216]

This is by far the Best, easiest to undrestand and most awesome explanation (atleast for me) that I found In 24 hours of my study on transistors even in 2021. THANK YOU!

[@jimc52]

Ii love your elegant and simple illustrations and explanations. This was very well done.

[@kevpatt]

Thanks!

[@jasongreen5360]

Best video. After 2 years, I finally understand the difference

[@kevpatt]

+Jason Green Awesome, thanks!

[@464340]

+Jason Green .you are lucky. it takes 4yrs for me.

[@davebalz4039]

Excellent. Clear. Understandable. No frills. Great teacher.

[@jimedgar6789]

Years I have tried to grasp this. Wow... thanks.

[@nikosadie]

best explanation yet. Now I start to understand the basis of transistor use in amplification.

[@IBullsHit]

I was struggling to understand the difference between npn & pnp.Your last statement clarified everything for me : control signal has to be lower than 5v to turn on a pnp and control signal has to be higher than 0v to turn on npn. Thank you!

[@tigerseye73]

As a welder, I learned long ago that DC voltage flows from negative to positive. You can weld with the electrode set up at either polarity, but electrode negative results in a deeper puddle ( more heat into the work piece ), and cooler running feed wire. Reverse the set up and you have just the opposite outcome. Just saying. Your presentation is very well done and thank you for sharing.

[@kevpatt]

Yes, conventional current flow (as used on schematics), is the opposite of electron current flow. Still no excuse for drawing the battery symbol upside down! :( Thanks for the kind remarks!

[@xpress021hundred]

Thank you, good sir, transistor basics are a lot clearer to me now! Keep up the good work! I would absolutely love to hear more of your own spin on electronic tutorials in the future! For instance; radio frequency/communication systems explained easy.

[@kevpatt]

+qdnguyenbp I will certainly be making more videos as I have the time. Thanks for the encouragement!

[@hambernat6444]

I also watched eleven or twenty transistors videos before this one. Yours was the best. Excellent job!

[@moegasim]

The clearest explanation found...thanks for sharing

[@mpl868]

Why don't you come to my university as my lecturer? Nice presentation for npn and pnp transistor!! I could save a few weeks if I find this video early!

[@umbratherios5614]

FINALLY! A video I can understand and actually learn how transistors work! Thanks man :)

[@kurtlittlebridge]

I watched this many time before I finally got it and even though I'm still not sure. However, I feel I have enough of a grasp to implement it in my circuits. Thank you!

[@kevpatt]

+PS Awesome, keep at it. I started learning electronics when I was just a kid, and it's amazing when I look back and realize how little I actually understood and all the misconceptions I had. However, perseverance and study will get you there. Sometimes experimentation is the fastest way to learn. :)

[@3deeguy]

Excellent tutorial. The BJT is a "current multiplier". The PNP emitter faces power, the NPN emitter faces ground.

[@steveo7052]

Best transistor explanation ive seen thus far!

[@kevpatt]

Thanks!

[@marcusventer8609]

The Best Explanation Of NPN/PNP If Seen. Just the right type of Vid for a beginner like me

[@kevpatt]

Glad you found it useful!

[@GamersMedia2723]

thanks kevin petterson this is the best tutorial i have seen yet

[@kevpatt]

Aashu Malik You're welcome!

[@7999rahul]

Simplest and best video I found. Great explanation. Many thanks.

[@kevpatt]

You're welcome!

[@nkacarova4000]

You are the best man! So simple you give us light with how it works! So many videos here in youtube for this topic, but this is the best one!

[@mcmx88]

Absolutely fantastic. Best explanation I've seen. I finally understand. Thank you!

[@denzelnolet]

Pity you never made more videos. You have such a way at explaining these concepts.

[@PLMHero]

I've been watching lots of video about transistor. But yours is my favorite. It answers my questions.

[@thenet0120002]

Great video on the basics of transistors clearly goes over the current flow and the function of transistors theory.

[@alexanderjustinkonga6447]

For a first time i can make my Simple circut of a Transistor. So i say Thank you Sir. -from Tanzania East Africa

[@monkporfyrius97]

You made it simple for me , i've watched many videos about transistors and everybody is trying to be so coplicated ( you see coplicated is more kickass than simple).

[@JamesKelly89]

One way of memorizing which symbol is NPN is that the arrow is; Not Pointing iN

[@markschuurman4000]

And my way to memorize: nPn needs Positive on its base, pNp needs Negative. And the arrow points the direction of current. What's so hard on that?

[@kennmossman8701]

The 'P' is in the middle....and rhymes with Pee

[@cuttyflam6136]

best explanation I've seen anywhere, thanks so much

[@kevpatt]

+Cutty Flam You're welcome!

[@jimmychen119]

Amazing! As an outsider, I learned a lot from this video!!

[@kevpatt]

Awesome!

[@PreludeSon]

Very good explanation, easy to understand and the drawing helps a lot.(battery symbol is flipped)

[@kevpatt]

+InfinityOrchid Thanks! Yeah I drew the sketch and turned it around, forgot about the symbol. Quite embarrassing. :(

[@lucysluckyday]

OK, I had my doubts when it started going by the battery symbol, but I actually watched out of curiosity and this is really good!

[@MrRanmaedu]

Good video my good sir. The inverted symbol of your power source is in fact inverted but you are aware of it. Thank you for your video

[@kevpatt]

+MrRanmaedu Thanks for the kind remarks.

[@impulsivez4825]

This is best explanation by far thank you. Was so confused on how to set it up.

[@1yyymmmddd]

Never seen such a clear explanation. Excellent! It might be also useful to show some practical examples, i.e. say we have 5V battery, 2K base resistor, which provides xx mA to the base and that results in yy mA current through the LED.

[@kevpatt]

+1yyymmmddd Thanks for the kudos. I do have another video that shows the circuit in action (in a simulator), and I think it shows some numbers too. Check it out: kzbin.info/www/bejne/f5-kna1ro5yHmLc

[@tomasfranco4870]

Perfect video mate. Still helping people in 2021. Thanks

[@AB1Vampire]

Appreciated the explanation of difference between PNP & NPN at the end of video.

[@davidpeters7447]

Nice explanation. Easy to understand and no confusion.

[@Rising_Pho3nix_23]

Struggling to learn this stuff, I took a screen cap at 7:39 and printed it off. This helps a lot thank you!

[@kevpatt]

brandon day You're welcome! Keep studying, the learning pays off!

[@haloomar2906]

finally i understand how transistor work as a switch i watched many videos but yours is the best

[@Traderhood]

Best explanation ever, and I have been through bunch of tutorials on youtube. Thank you.

[@jasonmurawski5877]

Thank you for this video, i was having a very hard time understanding the difference between the two with what i read on google, watched this video and instantly understood it.

[@ryanmurphy3011]

In the U.K. especially in industry, PNP based sensors are a lot more common. That’s because you’re switching the positive terminal of the load. It makes much more logical sense to use these transistors for references as it’s more practical. As most people will treat an output from a sensor as a positive terminal and look for a negative reference.

[@Marc_Miller]

Thumbs up for hand sharpened pencil and nice drawings. And great explanation of NPN and PNP.

[@raghavvsrinivasan9645]

Seriously, I have seen like about ten videos and none of them had such a simple and easy circuit. Great video, great explanation. Eager to see your next videos. Do something with LDRs. I also subscribed ;)

[@kevpatt]

Thanks!. Do you mean LDOs (Low Dropout [Voltage] Regulators)?

[@tonyvtech25]

Awesome video super understandable LOL. Finally i understand how transistors work and the difference between PNP and NPN. Thank you very much kevin.

[@kevpatt]

You're welcome!

[@radioscout]

Finally an easy to understand explanation

[@johnr625]

Very well explained, one of the best on KZbin. Thank you

[@Michealfarmer]

Thanks for the great video. Finally learnt something useful about PNP transistors! Cheers!

[@kevpatt]

You're welcome!

[@blockeduser5769]

Great Explanation NPN feeds a ( - ) to the load PNP feeds a ( + ) to the load.

[@DaisyLech]

Thank you! This is by far the best explanation.

[@kevpatt]

You're welcome!

[@del9936]

Great explanation of transistors,only thing is electron current flows from negative to positive and not current flowing from positive to negative as you described in the video .

[@hooverzavala8071]

Best explanation ever. Finally i get the idea about PNP trans. Too bad you dont have hundreds videos regarding electronics

[@utkf16]

Great explaination very clear and pitched just right for someone, like me, fairly new to electronics

[@michituurbentaler1378]

Great! exactly that explanation i was looking for! Thank you.

[@kevpatt]

+michi tuurbentaler You're welcome!

[@james66872]

This the best tutorial so far.

[@kevpatt]

Thanks!

[@SABIRALI-gf3fv]

Thank you Mr. Kevin Patterson ,Nice video & Explanation.

[@kevpatt]

Thanks!

[@warsymphony]

FINALLY a good explanation of transistors!!!

[@kevpatt]

Joshua Foster Thanks!

[@orvillellewellyn9525]

Your lesson was well done and easily understood.

[@HenriqueMarquesFernandes]

Just awesome video! cheers from Brazil!

[@kevpatt]

+Henrique Marques Fernandes Glad you liked it. Cheers!

[@464340]

Simply superb.very easy to understood. thanks a lot.

[@kevpatt]

You're welcome!

[@1Robbie75]

well explained. why there are two different types of magnetic inductive proximity sensors pnp and npn?

[@sandeephooda9253]

I haven't see any simple explanation then this one. Thanks Kevin. I was wondering if you user battery positive and negative representation correctly. Generally I have seen positive terminal line length greater than length of line representing negative terminal. Any how great explanation.

[@atelesia]

Best explanation.Simple and easy to understand.Thanks :)

[@kevpatt]

+atelesia Thanks!

[@mattserone3381]

That was a very good precise informative video..thanks pal keep producing great vids

[@kevpatt]

Thanks!

[@jaydean5243]

Excellent presentation- the best I've heard , one question the battery presentation seems reversed the positive end should be at the longer line and neg. end should be at the shorter line. Thanks for the vid.

[@brantwinter]

Great video. Would it be possible to get a video on choosing appropriate base resistors ?

[@kevpatt]

This can be calculated using Ohm's Law: I(current) = E(voltage) / R(resistance). ([Supply Voltage] - [B-E Voltage Drop]) / [Resistance] = Base Current. For example, let's say your desired base current is 5 mA (0.005 A), and your power supply is 5V. Let's say the datasheet for your transistor indicates that the Base-Emitter junction has a voltage drop of 0.7 V. First we will subtract the voltage drop from our supply voltage: 5V - 0.7V = 4.3V. This is the voltage that would be "seen" by the Base-Emitter junction _without_ a resistor, and would supply an unlimited amount of current (as much as your supply can provide), likely destroying your transistor. To get 5 mA base current, we will use Ohm's Law: I=E/R : 0.005A = 4.3V / R(unknown). Do some algebra to solve for R (multiply both sides by R and divide both sides by 0.005A). : R = 4.3V / 0.005A : R = 860 ohms.

[@jawadazam9707]

nice explanation sir . you made it really easy to understand . hats off .

[@kevpatt]

Thank you!

[@NeonblueIndustries]

Yes BRILLIANTLY explained! Thank you man! Great Video!

[@kevpatt]

Thanks for the kind words. You're welcome!

[@bkzzzzz]

very helpful and nicely explained! first time I completely understand the difference between these two Transistors. look forward for more videos. there are many people out there on youtube who explain things but very few like you who explain it the way that the person will never forget and will have almost no doubts after completely watching it.