Tutorial: How to design a transistor circuit that controls low-power devices

[karachiluvrs21]

I have done electronic engg but i don't know how to design electronic circuit but i have good knowledge about devices used for designing.Can you tell me how can I learn to design circuits???

[directcurrent10]

what course should i take in college to learn that kind of works.! co'z that is my hobbies..~ ! its electrical engineer or electronics engineer???? tell me pls i'm curious.!

[bkraz333]

@directcurrent10 If you take electrical engineering courses in college, you will probably learn a fair bit about transistors. If you study on your own, visit a hackerspace, read books, find a mentor, you will probably learn a lot more. Good luck!

[directcurrent10]

@bkraz333 that is a website??

[MrJaffaMicroBrain]

Really good tutorial. I salute you sir and hope that you can produce and share more.

[CYBERlite2010]

Finally, a way to control a motor requiring 12 V from an Arduino and L293D. :)

[madamerotten]

Sure they make 4300 Ohm resistors. That's a standard +/-5% value in the EIA E24 series.

[icegate2901]

The shining mon can not make it clerer, If any one can, Mr Easter can can

[ChuffChuffWoo]

Very good video! I'd probably have used a 2k2 in the base leg to provide plenty of headroom - depends how much current loading the driving signal cam provide, I often drive transistors off CMOS logic or LM339s and LM324s

[ggattsr]

You have a gift for making complex topics very easy to understand. Thanks for sharing your gift with those of us with a never ending passion for all things electronic. Great website also. I just subscribed to your channel.

[Memscan182]

Thanks Ben for the videos.  I just subscribed to your channel and for a technician in electronics it's very nice to keep up to date and refreshed on our technical notions.

Thanks. Nice Videos.

[MijnheerM]

Thanks for the video!

[lartti83]

Sorry, you answered that in the video.

[lartti83]

What would happen if we choose much smaller base current? Maybe a current that would make Ic -current only 1mA. Would the device still work(switching)? It would be connected to 12VDC but the current would only be 1mA. You said that you can decrease the current with transistors but not increase it.

[Tda7000]

Great video! Easy to follow but still gives good information. Much better than the one Sparkfun did, in my opinion. I hope you will do more!

[omgwtfbbqlol33]

Great video, thanks a lot :D

[ehav62]

Great video. Keep them coming.

[cozzbp]

You taught me more in 21 minutes than my electrical engineering professor taught in an entire semester of electronics design.

[salilphadnis1]

Thank you for this tutorial. Learnt a lot. Keep them coming.

[AdvocatusDiabolii]

thank you, I finally understand transistors :)

[EA78751]

top notch lecture!

[NathanBBrooks]

This is a great introduction to transistors! It is very much in the style of some of the Khan Academy educational videos. They don't have an electronics section (yet) but this would be a great video to start the section with - you should contact them!

[sf17k]

I've tried to get into electronics as a hobby several times, but could never find good tutorials before. This was very practical and comprehensible, thank you for demystifying the arcane magic!

[clockwork666]

thx, after years i totally forgot how to do this :)

[GSR600Relaxed]

thank you...that helped me alot!

[druidamixyt]

Very helpful videotutorial. Plese, can you make more basic tutorials about electronics like this one?

[danzarb]

Loved it!!!, Very best transistor video on Youtube! Look forward to more on circuity type items

[ersi89]

The video and audio is great and very well done / edited / shot. Keep it up!

[bladder1010]

Very clear and concise explanation!

[jpfo1776]

Great! As an old guy who grew up on vacuum tubes, I well remember the old days as I graduated to early transistors. These days it's chips with everything but looking back, I made great use of the BC109 NPN tranny ..... good hfe but also good for gen switching. Used to enjoy building projects and almost feel I should resume. Thanks for a pleasant trip into nostalgia!

[pooyae82]

Great work as always. A talk about common protection mechanisms on circuits would be great, especially for students of electronics that do not have much experience in designing circuits. (diodes, filtering capacitors,...)

[vbCrLf]

Great video!

What I like about it is that you explain why you chose every component and why you connect them this way. It helps a lot with understanding circuit design. I really like this video.

One thing that would make it better: When you say that you checked some information in the datasheet, tell us how to find it there (and how it is called) so we can find it for our components :)

Thank you!

[shrumby]

Absolutely outstanding! I've been into electronics my whole life and have always found transistors to be a mystery. You have totally simplified them better than any text book I've ever read.

Please keep up the good work!

[sharkovios]

@superdau thanks..

[sharkovios]

Excellent job.

1 thing i dont get. How hfe is 100? I read the datasheet and it mentions about 10 gains at diferent conditions. How Can i choose 1?

Thanks.

[superdau]

@sharkovios

Multiple transistors of the same model can have quite different hfe (the production process isn't perfect). So you have a min/typical/max in the datasheet. It's also dependent on the current you want to switch, so there sometimes are several lines of hfe. For switching applications just take the lowest hfe for your current range to be on the safe side (in this case the transistor will be fully on when you want it to be).

[cmxcmx]

Very interesting. I'm happy I subscribed to your channel :)

It's been a long time since I did anything with electronics (and that was only very basic stuff) and I'm thinking of getting back into it a bit more seriously. I like that you take the time to explain some of the practical issues instead of "just theory" - though theory is appreciated; I have a hard time internalizing equations.

[bkraz333]

@cmxcmx Great! Welcome to the hobby. Let me know if you are interested in hearing about any topic in particular. There are probably many other people with similar questions.

[pcbheaven]

Ben, really, you are the man. I will feature this video in my site. Excellent explanation!

[nukwaste]

Your presentation explains the material very well. This is great.

[AntiProtonBoy]

Good stuff as usual!

[g60scuzz]

Thanks for sharing I definitely learned from this. If you do another video like this I would be curious about base current control techniques with the PNP transistor.

[superdau]

The voltage drop of a junctions is highly current (and temperature) dependent. So if you talk about 0,6V it's for very low currents, where a diode is just starting to conduct. The higher the current the larger the drop. A standard 1N4007 diode has almost 1V drop at 1A. It's similar for a Base-Emitter-junction.

Keep that in mind when dealing with high power transistors. Their V_BE can quite above 1V at high base currents. (and V_CE will be way higher than 0,1V, too; more like 1-2V)

[bkraz333]

@superdau Thanks!

[Films4You]

Excellent electonics video lesson... Please keep them coming :)

[JingleJoe]

12:52 it's between .6 and .7 It varies for all components with PN junctions because you can't make two components EXACTLY the same, so for diodes or transistors it's somewhere between .6 and .7 however for calculations it's safer to assume it's .7

great video anyways, helped me understand some more things in better detail :)

[k0rmus]

Amazing lecture. Really great explanation (slightly advanced details, but well explained and not confusing)! I like you try to draw everything more than once -- nicely and clearly. Thank you so much!

[orbiter8]

Absolutely awesome Ben. More like this please.

Thank you for taking the time to do this. It really helps.

[bear24rw]

That was a really awesome explanation! I would love to see more videos like this.

[Latrocinium086]

You start with a DIY electron microscope and now this.

You Sir Rock!!!

[hpebley3]

Great level of explanation, technical enough to learn from but not so much that it overwhelms. Thanks!

[clide8]

Very helpful and well explained, thanks.

[blaisemibeck]

Good show!

[supermaucat]

So awesome! Thank you for this! Love the basic videos like this one... I can actually follow this and it's not way over my head :)

★★★★★

[BHR477]

thanks for the tutorial,, keep them coming :)

[xXdenhartXx]

Awesome vid :)

[MidNitRcr1]

This is an *excellent* tutorial. As someone who never went through an EE program, having something like this is the only way to learn more complex concepts beyond which components do what. Please make more! and keep up the good work.