Thank you so much. A very clear and informative video. I really like these series. They are so much better than just a presentation of formulas. I'm going to have to watch it a couple of time for it to sink in. But its the best one on BJT out there. A video on NPN's and their usage would be really good.
This is easily the best video I've seen concerning the steps of logic, caveats, and misdirections I've seen, regarding the transistor choice process. Thank you!
At 15:24 , with your third try , I knew the story has not ended as there are 10 minutes left :) Joke aside, what a great way to show me how to solve this problem. I am an electrical engineer , but only practised engineering for few years before I moved on. I hope you have full series of videos for people like me who want to come back to their calling , have more then basic knowledge but lack practical experience. Thanks a million
i just watched the best bits again. i think, in some respects, you are superior for Mehdi. He tends to race over the data-sheet details rather quickly. your method of slowly covering all the relevant information is amazing.
of course we want a fet vid. thanks to you i already no longer think of mosfets as for high V applications, and instead think of them as suitable for low I applications. i spent ages playing with 520s on BB on my bench. fascinating how i can turn them on and off by touching the gate and with other hand touching VCC and ground. i saw mehdi do it once, whilst saying " bing, bong, bing, bong" but it wasn't until you covered mosfets in your previous vid that i finally grasped the internal capacitor.
Your approach imbues theoretical concepts with real-world meaning, providing essential knowledge for selecting transistors tailored to specific applications.
wow. when you make a new vid, i open my lab bench book to a new page and start making notes. your video essay on the diode was a revelation. this vid is another triumph.why can i not thank you with a few quid through YT thanks? (edit, like an idiot i didn't find the thanks button, lol) you are up there with mehdi sagdagaar and bigclive! thanks
Hi, I really liked your explanations about choosing the right BJT. I would like to add some points for selecting the right device. Using your example of a collector current requirement of 2A, choosing a device with 5-10A is a good starting point. Most maximum continuous collector current specs IC (DC) are assuming an IC/IB of 10 or 20 to stay within the allowed power dissipation Ptot of the device. So, you should over-spec the device on collector current to keep Ptot low. You should also look at the conditions for the Ptot specification. For a through-hole device like TO-92, it is simple. But for devices like TO-220, you have to look at the specified cooling conditions. For SMDs, you have to look at the solder area (footprint, 1cm2 cooling pad, etc) and the amount of PCB layers used for the Ptot spec. The next parameter you should look at is hFE. If the hFE at low collector currents is about 50, you will not be able to drive this BJT with low base currents at IC=2A.You should look at the "Low VCEsat" types of major suppliers like Diodes, Nexperia, On Semi and Rohm (in alphabetical order). These have usually higher hFEs and VCEsat curves in the datasheets for IC/IB ratios of 50 and/or 100. Look for a device, that still has low VCEsat at IC/IB of 100 and 2A. Looking at VCEO, you should not overspec too much there, as higher VCEO for the same internal transistor area translates to losses on the other electrical parameters like hFE, IC (DC), VCEsat, switching time). For example, it is very hard to find a BJT with VCEO>100V, that has a high hFE of 200-400 and a very low VCEsat and fast switching. If switching time is a consideration, Darlington BJTs are the slowest. Driving a single BJT with a very low base current, i.e. not into deep saturation, helps here. Special Switching BJT normally have higher VCEsats as a trade-off and are not always an alternative. My employer recently published a BJT Application handbook, if you really want to dive deep into BJTs: efficiencywins.nexperia.com/efficient-products/bjt-application-handbook. You can find a direct download link, if you search for "BJT handbook" on the Nexperia website.
Thank you for the videos. I am looking for a small laser driver with a transistor. When I switch on the power to the constant current source, there is initially a short flash of the laser diode. Do you know how to limit the initial current to a constant current source ?
Did you see the transistor based current limiter circuit in the transistor application video? I mean '7 awesome application of transistors in circuits'?
@@elewizard And there is no golden rule by experience? For example, let's assume that a small-signal transistor in a TO-92 housing operates with a collector current of less than 6.94mA and does not exceed half of the maximum Pd, i.e. 0.5W/2=0.25W. The maximum allowable Vce for this particular bjt is 45V while the supply rail voltage will never exceed 36V. Thja=200K/W but I assume that the circuit will never operate at temperatures greater than Ta=50°C. So the junction temperature range will be 68-100°C(Tj max=150°C). So everything seems to be matching specs. Will 9V margin be ok or not so much?
Thanks ❤a lot for such a helpful content on electronics plz share link of Sit from where you are bying or seeing detailed description of Transistors and plz also share site if you kknow detailed description of IC's, make a detailed video on arduino plz plz I will be thankful
Thanks. Is there an online, semi-comprehensive spreadsheet listing BJTs*** with all their important parameters. This would allow informed searching by sorting/choosing parameters sequentially from most to least important -------------------------- *** and/or another spreadsheet for FETs
i'm trying to understand what advantages if any the BJT has over a FET in this sort of application? it seams like the BJT is very inefficient and wasting a lot of energy to heat
یه سوال هم دارم تو یه پروژه ای باید ۶۴ تا ورودی به میکرو بدم مثلا اگه خروجی ها زیاد باشه میدونم باید از شیف رجیستر استفاده کنم برا ورودی باید چیکار کرد
In switching applications, hFE is almost irrelevant. For most switching BJTs you design for an hFE of 10. That is specified by the manufacturer to ensure that the base is overdriven pushing the transistor into saturation. That is why the data sheets almost always quote Vce(sat) with a ratio of Ic:Ib of 10:1. The power dissipation will be Vce(sat) x Ic and you then can work out how big a heatsink you need since you want to keep the junction no more than about 125°C above ambient. That means Pmax = 125/(thermal resistance junction-to-case + thermal resistance of heatsink). Note that you would need an infinite heatsink to achieve the power dissipation quoted in the datasheet at a case temperature of 25°C. Realistically, It will always be less than that.
The points you mentioned are not understandable to newbies, i think such points has to be presented to someone that is experienced. Anyway, thank you for your nice and informative comment 🌷
@@elewizard I disagree. Designing a BJT switching circuit to use a base current one-tenth of the required collector current is well within the grasp of any newcomer. Compare that with your description of hFE and the calculations you suggested for base current and you'll see.
The goal of the video is to introduce some parameters of BJTs and explore the datasheet, maybe I am wrong. However I appreciate the time you took for writing these informative comments 👍
@@elewizard I do understand your aims in making the video, and I appreciate your concern to keep it simple to ensure it is understandable for an inexperienced audience. Nevertheless, I have found over the years that there is a general misunderstanding of the relationship between base current and collector current in switching circuits. For that reason, I believe that every introduction to using BJTs as switches ought to emphasise that Vce(sat) is only valid when the base is overdriven. Thank you for the videos that you make; I do enjoy watching them, and any criticism I make is solely intended to help you when you revisit the topic in future.
It is obvious to an experienced people that the Vce(sat) is valid only the base is overdriven, but it took longer to a newbie to find that 👍 BTW, I like your T-Rex 🦖 avatar 🙃
There are several further important parameters of transistor, which are important for certain applications. If you consider switching applications especially for frequencies higher than a few 10 kHz, switching times (on / off) become very important. They are often not correctly implemented in the spice models of transistors. And yes, FETs are an important species, especially the MOSFETs for switching purposes. If you use a MOSFET instead of a BJT for low power switching you can often save a resistor, because you can directly control the gate with a controller output. When I need an inverted signal I nowadays often use a 2N7000 instead of a 2N2222. In high power / low to moderate voltage, fast switching applications MOSFETs are a must. Only at very high voltages (>500 V) you may use the advantage of IGBTs. IGBTs are not very common maker devices, because their real advantages are related with very high voltages and moderate currents (
Please note that there is no "collector-emitter junction". The Vceo parameter is the maximum voltage that the BJT will tolerate between its collector and emitter. That is often less than Vcbo, the maximum voltage that the BJT will tolerate across its collector-base junction, which really is a junction. It's helpful if you don't confuse the two parameters. The STMicroelectronics 2SD882 is rated for 12.5W with an infinite heatsink holding the case at 25°C. The key parameter is the thermal resistance junction-to-case which is 10°C/W. If you used a 10°C/W heatsink, you could dissipate up to 6.25W which is well within the dissipation at 2A when the transistor is in saturation (2A x 0.7V = 1.4W). The moral of the story is don't use cheap Chinese knock-offs with incorrect or inferior parameters.
Thank you so much for mentioning that the collector-emitter is not a junction. It was my lingual mistake 🤪 sorry for that. Anyway, thank you for the valuable information you provided in the comment.👍 and thanks again for improving my English skills 😊
Yeah, I know the sound is not very good, my main microphone's battery was dead, so I have recorded the voice using my secondary microphone. Sorry for that 😁
And please make a FET video if it's possible
Surely I will make it 👍
@@elewizardI am waiting your video about mosfets …You are great ..Thank you
@@elewizard Thank You very much for the podcast and I'm waiting for an episode about MOSFET selection and optimization guide.
This was fantastic!! Really helped me understand transistors more clearly with the excellent examples.
Glad you liked it! Keep watching
Excellent. I really appreciate the conversational approach. The problem solving is the key to me.
Glad it was helpful!
Thank you for being a part of the community 😊
Thank you so much. A very clear and informative video. I really like these series. They are so much better than just a presentation of formulas. I'm going to have to watch it a couple of time for it to sink in. But its the best one on BJT out there. A video on NPN's and their usage would be really good.
Thank you Peter for your encouraging comment ❤️❤️❤️
This is easily the best video I've seen concerning the steps of logic, caveats, and misdirections I've seen, regarding the transistor choice process. Thank you!
Your words inspire me to strive for excellence.
I'm thankful for viewers like you who make it worthwhile.
Perfect timing! I've got an overheating pair on an audio amp I just built. Your explanations are so much easier to understand then textbooks.
Great, I hope the video helps 👍
At 15:24 , with your third try , I knew the story has not ended as there are 10 minutes left :)
Joke aside, what a great way to show me how to solve this problem. I am an electrical engineer , but only practised engineering for few years before I moved on. I hope you have full series of videos for people like me who want to come back to their calling , have more then basic knowledge but lack practical experience.
Thanks a million
Thank you for being a part of this journey!
It's comments like yours that make creating content so fulfilling.
i just watched the best bits again. i think, in some respects, you are superior for Mehdi. He tends to race over the data-sheet details rather quickly. your method of slowly covering all the relevant information is amazing.
Wow, your kind words made my day dude 😃
Thanks a million for the £2 support! 🌈
Please do more videos like this. Very useful
Glad it was helpful, 😊, cheers
of course we want a fet vid. thanks to you i already no longer think of mosfets as for high V applications, and instead think of them as suitable for low I applications. i spent ages playing with 520s on BB on my bench. fascinating how i can turn them on and off by touching the gate and with other hand touching VCC and ground. i saw mehdi do it once, whilst saying " bing, bong, bing, bong" but it wasn't until you covered mosfets in your previous vid that i finally grasped the internal capacitor.
Great, so you are familiar with FETs. I will cover more info about FETs in my upcoming videos 👍😃
i just watched it again. the way you explain the breakdown voltage is fantastic. and i figured out the thanks thing. thanks.
Glad the video was helpful 😃 and thank you for the generous £2 contribution! Much appreciated!
Your approach imbues theoretical concepts with real-world meaning, providing essential knowledge for selecting transistors tailored to specific applications.
Really happy to hear that 😊
wow. when you make a new vid, i open my lab bench book to a new page and start making notes. your video essay on the diode was a revelation. this vid is another triumph.why can i not thank you with a few quid through YT thanks? (edit, like an idiot i didn't find the thanks button, lol) you are up there with mehdi sagdagaar and bigclive! thanks
Wow thank you for comparing me with such a great creators 😃
Best explanation of BJTs I've ever seen! A video about MOSFETs gate driving will be great.
Glad you liked it! Surely I will do the same work for FETs👍
Another excellent video! Very well explained, especially the reasoning behind which one to choose!
The way you are teaching is fantastic please continue with it and do the same for FET as well
I appreciate your kind words!
Will do as soon as possible
Thank you for your enlightening content. Wishing you ongoing inspiration and impact.
I appreciate the positive vibes you bring to the channel.
Your encouragement keeps me motivated.
I appreciate the positive vibes you bring to the channel.
Your encouragement keeps me motivated.
One of the finest , easy to understand explanation on transistor sizing. Can't wait for the FET version!
I will make the FET video as soon as possible!
Fun and informative video, it really felt like a story and was able to discuss each parameter nicely.
Glad you enjoyed it!☺️
Thank you. This was so enlighting. 🎉🎉
Thank you for being a positive force in the community❤️❤️
Very helpful & informative. Thank You 🙏
You too❤️❤️
Thanks!
Big love for the AED250 Super Thanks! You rock Hussain ❤️❤️❤️
We need the same video for FETs. Thank you.
+1
Yeah, I will make the same video about FET as soon as possible 👍
Super useful video! A similar one about FET transistors parameters would be awesome too!
Thank you for your encouraging words! And thanks again for being a part of the community ❤️❤️❤️
Amazing video! Everything explained very well
Thank you so much
Thank you too for watching 🥂🥂🥂
Hi, I really liked your explanations about choosing the right BJT. I would like to add some points for selecting the right device.
Using your example of a collector current requirement of 2A, choosing a device with 5-10A is a good starting point. Most maximum continuous collector current specs IC (DC) are assuming an IC/IB of 10 or 20 to stay within the allowed power dissipation Ptot of the device. So, you should over-spec the device on collector current to keep Ptot low.
You should also look at the conditions for the Ptot specification. For a through-hole device like TO-92, it is simple. But for devices like TO-220, you have to look at the specified cooling conditions. For SMDs, you have to look at the solder area (footprint, 1cm2 cooling pad, etc) and the amount of PCB layers used for the Ptot spec.
The next parameter you should look at is hFE. If the hFE at low collector currents is about 50, you will not be able to drive this BJT with low base currents at IC=2A.You should look at the "Low VCEsat" types of major suppliers like Diodes, Nexperia, On Semi and Rohm (in alphabetical order). These have usually higher hFEs and VCEsat curves in the datasheets for IC/IB ratios of 50 and/or 100. Look for a device, that still has low VCEsat at IC/IB of 100 and 2A.
Looking at VCEO, you should not overspec too much there, as higher VCEO for the same internal transistor area translates to losses on the other electrical parameters like hFE, IC (DC), VCEsat, switching time). For example, it is very hard to find a BJT with VCEO>100V, that has a high hFE of 200-400 and a very low VCEsat and fast switching.
If switching time is a consideration, Darlington BJTs are the slowest. Driving a single BJT with a very low base current, i.e. not into deep saturation, helps here. Special Switching BJT normally have higher VCEsats as a trade-off and are not always an alternative.
My employer recently published a BJT Application handbook, if you really want to dive deep into BJTs:
efficiencywins.nexperia.com/efficient-products/bjt-application-handbook. You can find a direct download link, if you search for "BJT handbook" on the Nexperia website.
Great explanation. Love to hear more about FETs. Cheers,.
Awesome, I will make it as soon as possible 👍
Yes, another about MosFet selection please
OK, thank you for your feedback ❤️❤️🌷
Lot's of great knowledge has been shared here. This would be hard to obtain 40years ago.
Thank you for your positive energy ❤️
Inspiring! Thanks
Waiting to hear more.
Thanks for listening. ❤️
Thank you for the videos. I am looking for a small laser driver with a transistor. When I switch on the power to the constant current source, there is initially a short flash of the laser diode. Do you know how to limit the initial current to a constant current source ?
Did you see the transistor based current limiter circuit in the transistor application video? I mean '7 awesome application of transistors in circuits'?
What margin from the maximum allowable Vce voltage should be maintained for reliability?
There is no a standard margin, the more margin, the more the reliability 👍
@@elewizard And there is no golden rule by experience? For example, let's assume that a small-signal transistor in a TO-92 housing operates with a collector current of less than 6.94mA and does not exceed half of the maximum Pd, i.e. 0.5W/2=0.25W. The maximum allowable Vce for this particular bjt is 45V while the supply rail voltage will never exceed 36V. Thja=200K/W but I assume that the circuit will never operate at temperatures greater than Ta=50°C. So the junction temperature range will be 68-100°C(Tj max=150°C). So everything seems to be matching specs. Will 9V margin be ok or not so much?
Thanks you! Please post a video for fets too
Thank you too.
I will make it as soon as possible 😊
Not very good at electronic circuits, been learning all my life.
Hard to understand what you're saying but I think I learned some more today.
Great, keep trying 👍
Thanks ❤a lot for such a helpful content on electronics plz share link of Sit from where you are bying or seeing detailed description of Transistors and plz also share site if you kknow detailed description of IC's, make a detailed video on arduino plz plz I will be thankful
Search Google, almost everything is available on the web.
By the way, I am not a fan of Arduino 😁
Very well done, thank you.
Thank you too!
Thanks, great video, as usual.🙂 A similar video on FETs would be useful.
Sure thing! I will make it as soon as possible 👍
Thanks.
Is there an online, semi-comprehensive spreadsheet listing BJTs*** with all their important parameters. This would allow informed searching by sorting/choosing parameters sequentially from most to least important
--------------------------
*** and/or another spreadsheet for FETs
Yes, there are such websites
@@elewizard Thanks. Would you be so kind as to give a name(s) of such websites?
You did not watched the video carefully 😁
Alltransistors.com
I have mentioned that in the video 😉
i'm trying to understand what advantages if any the BJT has over a FET in this sort of application? it seams like the BJT is very inefficient and wasting a lot of energy to heat
Very good info. Keep up the good work with fet's to.
Thanks, will do!
Thank you for the lesson!
My pleasure! Thank you for being a part of the community ❤️
Thank You Electronic Wizard! 😊 👍🏻
Thank you too for watching 😊
Thank you very much for your videos.
You are very welcome
Great video. Thanks
Glad you liked it!
Sir our college professor asked us about an equation that turns electrical energy into mechanical in AC motors. Does anything come to mind
I have no idea what exactly your professor want. 🙃
@@elewizard that was literally the question. Write the formula that turns electrical energy from the generator into electrical.
Keep doing these videos i would like to watch these videos❤️❤️❤️❤️
Wow, thank you so much❤️❤️❤️❤️❤️
@@elewizard sir please do videos on different types of electronic components ☺️☺️☺️☺️
Will do 👍
@@elewizard thank you
Perfect ! thanks a lot.
You are very welcome ❤️
یه سوال هم دارم تو یه پروژه ای باید ۶۴ تا ورودی به میکرو بدم مثلا اگه خروجی ها زیاد باشه میدونم باید از شیف رجیستر استفاده کنم برا ورودی باید چیکار کرد
You can use I/O expander ICs like MAX7311
good video, thanks
Glad you liked it!
ostade aziz mamnoon .. 👌🏻
Hi Ali, welcome aboard ❤️
You’re really good master I which to have mentor like you
Your words inspire me to create more content. Thanks!😃
In switching applications, hFE is almost irrelevant. For most switching BJTs you design for an hFE of 10. That is specified by the manufacturer to ensure that the base is overdriven pushing the transistor into saturation. That is why the data sheets almost always quote Vce(sat) with a ratio of Ic:Ib of 10:1. The power dissipation will be Vce(sat) x Ic and you then can work out how big a heatsink you need since you want to keep the junction no more than about 125°C above ambient. That means Pmax = 125/(thermal resistance junction-to-case + thermal resistance of heatsink).
Note that you would need an infinite heatsink to achieve the power dissipation quoted in the datasheet at a case temperature of 25°C. Realistically, It will always be less than that.
The points you mentioned are not understandable to newbies, i think such points has to be presented to someone that is experienced. Anyway, thank you for your nice and informative comment 🌷
@@elewizard I disagree. Designing a BJT switching circuit to use a base current one-tenth of the required collector current is well within the grasp of any newcomer. Compare that with your description of hFE and the calculations you suggested for base current and you'll see.
The goal of the video is to introduce some parameters of BJTs and explore the datasheet, maybe I am wrong. However I appreciate the time you took for writing these informative comments 👍
@@elewizard I do understand your aims in making the video, and I appreciate your concern to keep it simple to ensure it is understandable for an inexperienced audience.
Nevertheless, I have found over the years that there is a general misunderstanding of the relationship between base current and collector current in switching circuits. For that reason, I believe that every introduction to using BJTs as switches ought to emphasise that Vce(sat) is only valid when the base is overdriven.
Thank you for the videos that you make; I do enjoy watching them, and any criticism I make is solely intended to help you when you revisit the topic in future.
It is obvious to an experienced people that the Vce(sat) is valid only the base is overdriven, but it took longer to a newbie to find that 👍
BTW, I like your T-Rex 🦖 avatar 🙃
Thank you.
useful.
You are very welcome!❤️
Very, very, very good!!
Thank you dude 😊
There are several further important parameters of transistor, which are important for certain applications. If you consider switching applications especially for frequencies higher than a few 10 kHz, switching times (on / off) become very important. They are often not correctly implemented in the spice models of transistors.
And yes, FETs are an important species, especially the MOSFETs for switching purposes. If you use a MOSFET instead of a BJT for low power switching you can often save a resistor, because you can directly control the gate with a controller output. When I need an inverted signal I nowadays often use a 2N7000 instead of a 2N2222.
In high power / low to moderate voltage, fast switching applications MOSFETs are a must. Only at very high voltages (>500 V) you may use the advantage of IGBTs. IGBTs are not very common maker devices, because their real advantages are related with very high voltages and moderate currents (
Thank you for your feedback, the information you provided in the comment is valuable and welcomed ❤️🌷
Thanks ❤
You're welcome 😊
FET's yes, please!
Will do as soon as possible 👍
Darlington Coupler😊
Please note that there is no "collector-emitter junction". The Vceo parameter is the maximum voltage that the BJT will tolerate between its collector and emitter. That is often less than Vcbo, the maximum voltage that the BJT will tolerate across its collector-base junction, which really is a junction. It's helpful if you don't confuse the two parameters.
The STMicroelectronics 2SD882 is rated for 12.5W with an infinite heatsink holding the case at 25°C. The key parameter is the thermal resistance junction-to-case which is 10°C/W. If you used a 10°C/W heatsink, you could dissipate up to 6.25W which is well within the dissipation at 2A when the transistor is in saturation (2A x 0.7V = 1.4W). The moral of the story is don't use cheap Chinese knock-offs with incorrect or inferior parameters.
Thank you so much for mentioning that the collector-emitter is not a junction. It was my lingual mistake 🤪 sorry for that.
Anyway, thank you for the valuable information you provided in the comment.👍 and thanks again for improving my English skills 😊
Opto Coupler😊
Make a FET video please!
Will do!
Varistor over Collector - Emitter😊
Where is the Wizard hat!?!?
I was here before the name change.
It was my old channel, the old channel is still available. My old channel name is X Electronix Master Club
Why not just use a mosfet?
Of course you can use a FET to switch a load
Data- Sheet😊
Over Voltage Schütz Zinc Oxide Varistor
سلام درود بلاخره چنلتو پیدا کردم خوبه که انگلیسی حرف میزنی با دیدن اینا انگلیسی ما هم خوب تر میشه و کار ت درسته
Thank you dude, thank you for watching
THERE ARE A LOT THINGS TO THINK ABOUT HERE.PLEASE MAKE PRESENTATION ON SELECTING FET'S.
Yeah, sure thing, I will make it as soon as possible 👍
Still waiting for the FET selection video😅
It is In my todo list
😊😊😊
please don't think i am being overly critical, but the sound on this was a little bit iffy.
Yeah, I know, the sound sucks. Because I have recorded the video using my secondary microphone 🫠 because of some technical difficulties
@@elewizard it doesn't really matter, i'd listen to you via 2 cans and a bit of string if i had to.
💖💖💖💖
❤️❤️❤️❤️❤️❤️
IGBT😊
You're good. Excellent, actually. But you need a proper microphone. Your audio is low and distant.
Yeah, I know the sound is not very good, my main microphone's battery was dead, so I have recorded the voice using my secondary microphone. Sorry for that 😁
@@elewizard Ah. Didn't know that. Thank you for the content.
What is your favourite transistor ?
I love TIP122.
Why? IDK!
Multiplicated with 4 x😊
Can you be a real wizard if you don't have a hat.... Thanks for this I had been trying to decipher transistor data sheets and this helped a lot
I am so glad that this video helped you 😃
Weird guy is back
Yeah, I am back 🤪
E.T. PHONE HOME !@!@!😂❤IGBT❤😊
1st
You are awesome ❤️
Thanks!
I'm smiling ear to ear with your £5 Super Thanks! 😊