Types of Diodes - The Learning Circuit
Ғылым және технология
In this episode, Karen reviews p-in junctions and talks about how they differ from other types of common diodes, such as schottky diodes, zener diodes, LEDs (light emitting diodes), laser diodes, and photodiodes. Connect with Karen on element14: bit.ly/2CD2ct4
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P-N junctions are considered your typical diodes. They have a p-n junction with a threshold voltage that has to be reached before current will flow through them. In silicon diodes, this is 0.7V. Once this is reached, the current will continue flowing. When hooked up backwards, in reverse bias, these diodes do not allow current to flow. If a diode is reverse bias, and it’s supplied with too much voltage, more than it’s breakdown voltage, it’ll “break-down” and current will flow through it in the wrong direction. Schottky diodes often look like typical diodes. But unlike p-n junction diodes, Schottky diodes have a metal-semiconductor junction. Silicon diodes require time for their depletion zone to grow and shrink when switching from allowing forward current to blocking reverse current. There’s a recovery time. Schottky junctions have no depletion zone. Because of their metal-semiconductor junction, Schottky diodes require virtually no recovery time and therefore have much faster switching speeds. This means they can handle switching current better and faster, which makes them useful in high frequency applications. They also have a lower forward voltage drop. Silicon diodes have a voltage drop of around 0.7V, but the voltage drop of Schottky diodes is between 0.15 V and 0.46 V. This means they lose less energy to heat, making them more efficient. Schottky diodes are not useful for all applications, as they can leak a small amount of current backwards. This could be problematic for certain circuits. While Schottky diodes can let some voltage leak through backwards, zener diodes are designed to allow current to flow in both directions. The p-n junction of zener diodes is heavily doped, only a specific voltage, the Zener voltage (Vz) can pass through without damaging the diode. In reverse bias, current will not flow through until the zener voltage is reached, but the voltage will be limited to the zener voltage. For example, a 3.3V zener diode will not allow current to flow until the supply voltage reaches 3.3V. If it’s supplied with 2V, no current flows. However, this diode could be supplied with 5, 6, 9, 12 Volts and it will regulate the voltage output to 3.3V. Zeners can have zener breakdown voltages of anywhere from 1.8V all the way up to 200V. LEDs, light emitting diodes, use energy from the particles moving through the p-n junction to create light. They can do this because they are made with gallium arsenide. Unlike silicon diodes, diodes made with gallium arsenide release energy in the form of light or photons. Like other diodes, they typically have 2 leads, though these can vary in length depending on the manufacturer. LEDs come in a wide variety of packages. Through-hole LEDs can be 3mm, 5mm, 10mm. They can have round and square lenses. Lenses can be clear or colored. 5mm round ones are the most common through-hole LEDs. Surface mount LEDs come in a variety of sizes as well. When choosing an LED, one of the first things you’ll look for is color, or wavelength. (Chart-VO) Here’s a chart of the color spectrum. Another choice you’ll have is beam angle or viewing angle. Beam angle is the amount of degrees where the light is visible. Depending on your application, you may want a narrow beam angle, like 10deg or a wide beam angle, like 120deg.
Пікірлер: 74
1:55 Most Replayed section + 0.25 playback speed. Very educational. 👍
I love videos like this. Great descriptions of how all of this works. I've learned it all before, but its nice to see it described so succinctly and elegantly in one place. Keep making videos like this.
My favorite part 1:59
@justbob1581
Жыл бұрын
I'm glad someone else was the pig and not me 🤣🤣🤣
Karen, we learnt these things in 1985. Its so refreshing the way you present things. In those days we had to go a grade up to grasp what was taught in lower grade. Electronics has been my favourite subject well before i started learning it. Its a passion.
I am studying to get my amateur extra licence in amateur radio, and I can't tell you how handy these videos are!!!! THANKS!!!
Awesome overview of diodes. I would like to see some practical application examples in a future video.
great video - very good explanations and illustrations
Excellent videos. I show them to my students in electronics classes.
and another video explaining the core concepts so well !
i have been ordering LEDS from element14 and i am very happy with the company,, they are very nice people. great customer service. my name is Bobby Dunn and i live in Nebraska.
I have found your videos to be a great resource for my students, thanks!
Learned something new about LEDs. Great video, as always, many thanks.
You don't khow much much good work you are doing. I feel like I should have the professor like you while doing my Batchelor's. Keep the good work.
A diode lesson well explained...looking for more similar videos from you...
Good work, I appreciate your effort for sharing your knowledge with us, I have two benifits from your videos , 1. I am improving my English 2. Getting knowledge 👍👍
Moga Allah sentiasa merahmati puan, terima kasih sebab banyak membantu
Gotta Love Karen.... taking something that could be rather boring and making it entertaining.
the amount of information being put into these learning videos are getting better :D makes it harder to tell newbies to watch different basics video. I really like karen in these kinds of videos. 9/10 from me keep it up, the only down side is pronouncing zener as ze-ner rather than zen-er, but thats just a pet peeve and isnt a bad thing at all just prefrence
@maker_karen1785
5 жыл бұрын
It's that problem that I think a lot of engineer-types end up having. If you only ever read a term and not hear it, you guess on the pronunciation. Like Kirchhoff. I say it kirch-off, but I've also heard it keer-koff. No idea.
@LordGarth6
5 жыл бұрын
yea that is the problem but so long as it doesnt venture too far from other pronunciations that it cant be understand what is being said then its all good (and i'll just have to keep my pet peeve out of it cause i may be wrong). the other problem for pronunciations are languages as i would presume that anything thats named after/or by a german person is meant to be pronounced the way a german would.
This was great! Right at a level that was useful for me.
Current will flow flow flow and flow. Awesome explaination.
I love so much this kind of video. I learned
Loving the 'rapidly' face! 😂
brilliant Karen! thank you
Awesome video!!
8:40 Albert Einstein received the Nobel Prize in 1921 for discovering the laws of the photoelectric effect. Unfortunately, it was not presented to him until December 10, 1922, since many members of the Nobel Prize Committee were skeptical about theoretical physics. This was also the reason why he did not receive a Nobel Prize for his theories of relativity, although the deflection of light by gravitation was already proven in 1919.
Fabulous! Thanks.
Thanks, Karen!
very informative.
So a Zener basically functions like an infinite resistor for anything but a specific voltage?
Hopefully Karen will detail the Transient-voltage-suppression diode soon. I helped a r/c motor designer (Big Jim Greenemeyer) get a hold of the surface mount ones to put on the commutator of '540' motors. Results were amazing.
@liquestjr.8683
3 жыл бұрын
Thanks
Madam I see your all videos and it is very useful and enjoying videos
Wow Karen's a great teacher.
thank you !
Super cool
Dear element14 please explain why cathodes are sometimes the (+) terminal and anode are sometimes (-) terminals because my teacher tells me cathode is the - and anode is the +
Thank you
I like it!
I want that poster on the wall. Do you know anywhere to get it?
@maker_karen1785
5 жыл бұрын
Not sure which poster, but the "The Art of..." posters are made by Vishay. I believe you can still order them off their website.
Im in loveee
How can I identify zener diodes from other diodes?
thats my kind of hot, and awesome lesson as well.
Thanks madam
She is so awesome
Awesome
1:57
Also, if you can see the beam of a low intensity laser... there might be a lot of particulates in the air or you just have super sensitive eyes 🤓😜
Zener LED?
It's mind game.
Maby some practical application examples in a future video? :D
@maker_karen1785
5 жыл бұрын
Check back this Wednesday! For every lesson we have, I try to put together a project that uses something from that episode. And that project episode usually comes out one week later. Stay tuned!
@StigDesign
5 жыл бұрын
@@maker_karen1785 Awsome :D
6:27 are you sure about that? I think 5mm LEDs can get to thousands of mcd
Says "didoes" in the description. Made me do a laugh.
I read that title as something entirely different the first time.
I love you
Would you know about flip flop
Beautiful. She is beautiful
Love the knowledge and female representation!!
only karen you cant hate
So, is Karen a Ham Radio operator?
@maker_karen1785
5 жыл бұрын
Not yet...
@ed-jf3xh
5 жыл бұрын
Been one since 1967. Used to be a lot of fun talking to South America with home made antenna. Hope it works out for you. Also good to see you involved in the tech side of life. Cheers...
Hy sist are you engineer?
👏👏👏📺📻
elementary school grade error.. 0.15 isn't read as zero point fifteen neither is 0.46 is zero point forty six. Strange that it hasn't been fixed two and a half years, for all the time this video has been up. Could be ignored if had been an individual's channel, but this isn't.
@Prash1c
2 жыл бұрын
Though this may be fair to say for formalities sake, it may be a wee bit immaterial... The idea is communicated and understood and, even if considered an error, it doesn't lead to anything bad... After all, there are many ways to skin a cat--and to read out a number.
eye candy and brain candy put together
The cringe is a bit too high for me in the one
@Derfboy
5 жыл бұрын
How so?