Electronic Basics #22: Transistor (BJT) as a Switch

In this episode of Electronic Basics I will show you how to use NPN and PNP Bipolar Junction Transistors as switches in order to turn on and off your electronic load with a control signal. This way you can, for example, use your Arduino to control loads that require more current than the output of the Arduino can handle.

Music:

[selvoselvo]

To fast for someone who doesnt know nothing. But good if you are already familiar with stuff,

[thomaspigg]

Although I don't understand any of it, I find it fascinating to watch and try to learn "just a little" each time. Not enough to do any damage but enough to get an idea.
Thank You Sir for your vids!

[jcolonna]

As someone who understands transistors I think you went too fast in this video. I didn’t have much time to digest the frames once they were only up for a few seconds at best

[NapoMMC]

I used to try base resistors until I found one that switched the transistor on without blowing it up. Now it all makes sense and I tried to calculate it using the formulas with a S9013. Worked perfect at the first try. It's the closest thing to magic ! :D

[digitART]

I think you make the best, comprehensive, clear and useful tutorials on YouTube, keep it up!!! Best regards from Zaragoza, Spain

[Reaper]

My head released some magic smoke at this video, too.
It's pretty fast.


(Well, I'm going to watch your basic videos anyway ;))

[TheCAPTAINman]

I wish I could add your vids to my electronics playlist for quick reference. Yours are so full of useful knowledge.

[deinahrsnoidson]

Best beginner transistor video that I've found so far. Well explained!

[UtkuDemir]

I really like you channel but in this video, it's like you're trying to show you've worked well on your lesson. I didn't understand anything at all.

[lloyddarbon]

I loved this video, although I was lost after about 20 seconds. I will watch it back with extensive use of the pause button. Otherwise my brain easily reaches a temperature of 70 degrees celsius.

[timehunter]

This actually helped a lot, spooky it appeared in my suggested, but I was actually wondering if I needed NPN or PNP for my project. Thanks.

[eumesmo-kdtr]

congratulations you move from advanced electronics to the very basics, very good keep doing

[calmarcalmar]

i little bit veeeery fast-forward... unfortunately. Less rush would be better for my taste.. but that's how it goes on 'GreatScott' :) EDIT: too fast for me.

[bibekkoirala]

If you go read a little about transistors at first and then watch this video, it makes a whole lot of sense.

[dalenassar]

I think this video has all of the information I need in it, but it should be about 15 minutes long. Anyway, I will re-view it a couple of times, and am sure I will absorb it.
THANKS FOR ALL YOUR GREAT VIDEOS!!!

[miladirani]

You are greatest scott on the world thank you i love your videos, from middle east

[veryinteresting]

These channels are best ! Low volume background music or non at all. More explanation which is what viewers value

[medjedovicm]

The crucial thing that I learned from your videos is that smoke is the main ingredient in every electronic component because when smoke goes out, the component doesn't work anymore...

[anishbhanja]

I think you are making this video only for yourself so that if you forget any stuff later on, you can refer your own video to recall that. Great work. Keep it up

[RexxSchneider]

You're calculating the base current wrong. You used the values for β given on the datasheets for when the transistor is operating in its active region with a Vce of 2V or more. If you look carefully at the datasheet, you'll see that the value for Vce(sat) is almost always given for collector:base current ratio of 10. In other words, the manufacturers guarantee the BC637's Vce(sat) of 0.5V max for a collector current of 500mA and a base current of 50mA. You can't just use the β of 25 that is quoted under different operating conditions. The same goes for the BD535; you can't just look at where the datasheet says β=15 and assume it will be valid when in saturation. It isn't and it won't saturate. If you look at Vce(sat) for the BD535, you'll find it is specified as if the β were 10. [Edited for typo]