Electronics 101: Bipolar Junction Transistors
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- čas přidán 4. 09. 2024
- In today's Electronics 101, we talk about the concept of BJTs, bipolar junction transistors. This is one of the two kinds of transistors we're going to talk about in the series.
As usual, I'm always looking for suggestions for future videos. If you have one, please leave them in the comments below.
Now back to your videos, very informative. Nice job!
You did a great job of breaking it down into digestible pieces. The falstad simulator is an awesome tip. I did not realize it would do all the math for me. Way cool. My math is all gone from my brain, mostly. Thank you!!!
Your tutorials are A+++++!!! I look forward to sharing these with friends who are interested in learning electronics. Please keep making videos...excellent communication skills.
thanks. By the way, I think you are awesome for taking the time to help strangers learn. I really appreciate it.
the arrow for NPN and PNP transistors should always be on the E terminal.
Still looking for a video that explains BJT physics correctly. This is not it.
Any suggestions for a better one?
My question is not about transistors, but about the tools you're using to write the tutorials. It looks so cool just like a paper and pencil where you can write and erase your mistakes at ease.
What is it that you use to write on your tutorials?
An iPad? Or something else?
The extra power comes from a separate power source. Sorry if that wasn't clear.
Awesome. I got solved my every question in my mind... Thanks Sir...
For me I got lost in this video because I didn't know what "the base" was. Found out, came back and got this more or less.
This may be a very basic question, but @13:31 when you draw the circuit on the top of the screen and you connect the voltage to the Motor (5v) and ground to the emitter end of the transistor, how is the circuit complete? Does the microcontroler have a power source? or is ground looping back to connect to the microcontroller? CIruit diagrams that do not connect have always confused me. Awesome videos! Really helps me understand digital electronics (learning analog before going there)
NPN = Not Pointing iN PNP = Pointing iN
That's how I remember how they look! :P
Thanks so much for this video! Commenting a little late, but it was really helpful now, as I am doing a course in this, and I missed lecture.
You've shown the collector and emitter backward on the PHP :)
It would be nice if you could do a few more examples, but overall an informative video
very helpful.
They offer a look-up table so that, depending on how much current you want to control, you can find that hfe value.
Ahhh ok. So a silicone transistor's hFE is 100.
And one more question:
You say the current from B usally goes to C. But if B has less current than C, it goes to E. And if C don't have any current it goes to E. I just want to make sure :)
please show us half wave, full wave, and bridge rectifier circuits
I'm kinda fuzzy on where the extra amps come from. If the micro controller only gives of .5 amps how does 2 amps come out of the transistor?
I'm confused with the hfe numbers in the data-sheet of the 2n3904. There are a lot of different numbers there and I don't know what the total hfe would be. I see Ic has a total of 200ma.
I am trying to switch well over 100amps at 50-100Hz. and 24vDc. for a inverter project. I am intimidated by the IGBT modules. and have concerns about using MOSFETs. I am self taught so there is a lot I do not know. I was thinking of using to220 or to247 get packages. but concerned about the current handling of the legs of the FETs. how much can they handle safely? and I guess I need to match them close as possible. but how close is good enough. I don't know if I am over thinking it. so I am looking for advice from professionals. I have been told to use shunt resistors on the FETs before the parallel buss. I was wondering if a fuse would also help with protection! and how many FETs would I need if they are rated at 100amps +/- . by what the package can can handle. or would a IGBT module be better. I am concerned about them exploding. if they are used at low frequencies. and kept cool can they be safely used. if they are even a small explosion it will cause a fire in my situation. or would FETs be better given my skill level. however on the out put stage. or H bridge could igbts be a good choice or would there be a even greater possibility of a shoot through explosion. even though there is only 20-80 amps max. your help would be greatly appreciated. thanks a lot. sorry for the rambling on!
I don't understand if you have a 3V battery and a 8 ohm resistor before the collector, and emitter is ground, max current should be .375A. What if base current is 10mA and hfe is 100, this says Ic should be 1A, but it's not possible.
Any chance you can put the notes in the description? Thanks!
Im pretty sure the arrow on a bipolar transistor is always next to the emitter, regardless of the type
Where does this 0.8 forward voltage drop come from? Never heard of this diode on the output of a micro-controller before, and I've been working with Arduinos a lot lately.
Hello! Thanks for the videos, they are very helpful in starting to mess with electronics, but i would like to ask about the simulator you use. Could you please tell me if it is free or it requires a license and also the name :)
It's a nice power of 10 number, makes the math easier.
Just saw that message your getting for low disk space is on your data recovery drive(d:). That means that drive is in use and it shouldn't be. I bet someone changed your paging file and selected D by mistake. That's why you keep getting a low disk message because windows keeps trying to use it and it's too small. Check your virtual memory settings and select a drive other than your recovery drive or let windows manage it. If you do set it the size will depend on the amount of RAM you have.
Re hfe ''going all over place'' just stick a little degeneration in emitter cct to minimise hfe variation and limit excess current through motor.
Does that simulator simulate speakers too?
Just a hobbyist....you went so fast, I had to stop and back up a lot. What is the circuit program you are using? No example of a pnp?
Um... how about the regions of operation? I believe BJT needs to be biased in order for it operate.
I just chose an hFE value. It's specific to the transistor itself.
Maximum current per pin on Arduino is 40ma.
Why is the next video private.....
Isn't alpha Ic/Ie?
are you using a mouse to doodle all this down, or some sort of pen with a button?
It's a Wacom tablet and pen.
The silicon diode requires 0.7 v to function. just being more precise :)
what is the simulator are you using
Mr Drive, where can I get that analog circuit simulator, it looks pretty cool!
snaprollinpitts www.falstad.com/circuit/
thamls
That is Bipolar? PNP or NPN or both?
Could you please explain to me why it is bad to use this example to control a
motor (or in my case a mini DC pump)?
Because he did not use any protection circuitry or such and the transistors would die.
when you look at a basic transistor datasheet (BJT), usually the transistor can't supply much current. But I think you can use a different transistor such as a mosfet to run a motor (correct me if i'm wrong). Humanharddrive has got a video on mosfets that's very informative.
Thank You, that helped !
how did you suddenly get hFE to get 100 at 12:10 ?
just thank youu :))))
Is the equation for alpha correct? Ic/Ie or Ie/Ic
ie/ic.. isnt it?
ic/ie i think
Changting Luo delta Ic/ delta Ie
why you assigned hfe = 100 ?
GGWP thx for helping me in uas
thankx
0.8 v? What kind of a diode is that?
how i can get your notes
please provide the link.
I Like your videos...but this one I got totally lost and didnt grasp the concept
What part is difficult to understand?
Hello.
What I understood from what you said at 6:00, was that if Ib was large enough, current would flow from C to E, even if Ic > Ib.
I simulated a circuit like the one showed:
www.circuitlab.com/circuit/dy8ru6/screenshot/1024x768/
And it seems that no current flows from left to right, even though the base is receiving a current of about 10A (which is enough to get the diode to let current through)... (There should be a current of 10kA...)
.6V for silicon and .3 for germanium aint it?
My mistake. The math still holds though.
@10:03 are you sure its Ie/Ic...I am quite sure its Ic/Ie
Holy shit Humanhardrive you are very confused re transistor operation. To Anyone else a pnp operates EXACTLY the same way as a npn but with reversed voltage polarity.
tnx :D x
I THINK YOU SHOULD MAKE THE ENGLISH SUBTITLE.
Your computer crashing might have something to do with those messages you kept getting in the other videos about "low disk space" or something like that and kept ignoring. LOL. I hope there was nothing wrong with the whiteboard because I downloaded it while I was watching. Opp's just saw another error message on this video. Your hard drive is low on space, it's going to crash again if you don't free up some space; you need empty space for windows to work. LOL sorry if already know.
Alpha= Ic/Ie. You have written it the other way.
NPN - Not Pointing iN
Do transformers and generators
Pointing iN Peautifully
Did you say Smart Board CAUSED you PC to crash? Now that you've had a chance to think about it, would you care to reconsider that theory ... ?
delete the naughty videos from your computer so you have more disk space hahaha
0.7 V not .8
I mean PNP, that's my Android guessing
the lack of hard drive space on your computer is the cause of the crash. Without a few extra gigabytes of space shadow copy and allot of other services won't work.
@ 1:35 You say it is labeled the exat same way. You are completely wrong.
Its no labeled that way at all. The Arrow is always the emitter in any configuration. You should not be making these videos. You are confusing people
this is vague. sorry but you didnt capture the basics of BJT. you rather skimmed through the main points
Sent a private message. PLEASE read it.
Regards, ScienceAdvisorSteve
your voice is hurting my ears. really