Voltage regulator tutorial & USB gadget charger circuit

The basics of linear voltage regulators - what they do, how to wire them up, and where to find them. Then I give a basic example of how to build a 5V supply that can power USB powered gadgets.
5 volt regulators: www.amazon.com/exec/obidos/ASI...
(Amazon affiliate link)
This video builds on material covered in my tutorial on building unregulated power supplies: • Diode Tutorial & How t...
Webpage: www.afrotechmods.com/
Twitter: / afrotechmods
Facebook: / afrotechmods

[@jerrywhidby5259]

Few people have the ability to teach electronics in an understandable way. You broke everything down into manageable bites. You didn't take for granted that I already knew something. I've always wanted to learn about electronics but many people over complicate their explanations. I subscribed just because I wanted to see if more of your videos were so clear and concise.

[@f.a3202]

Nice profile picture! You got me

[@BillAnt]

Excellent video tutorial... and hope he makes a few bucks along the way. ;D

[@mikegleasonjr]

@@BillAnt bucks converters are indeed covered in another video 😂

[@BillAnt]

@Mike Gleason jr Couturier < Jokes aside, I really meant "...makes a few bucks..." he-he

[@sandermez3856]

manageable bites or bits? im confused...

[@jasonbrindamour903]

I am watching a number of your tutorials. Very well spoken, well written and informative. This is exactly the type of lessons I am looking for. Well explained also. I like how much you explain about why (such and such) occurs.

[@BillAnt]

The difference in clarity and quality of this video compared to some others, is like night and day. Clearly flowing thought pattern, no mumbling and pausing, throat clearing, with a dash of well placed good humor in between. #Winning! :)

[@kaboomjones]

"Straight to the point electronics tutorial videos with practical examples". I AGREE! thumbs up.

[@shvideo1]

This is a great educational video. I learned a lot from your series on Power Supplies. Thank you for the comprehensive coverage of all the concepts and parameters. That's the proper way to learn instead of people simply demoing their work with inadequate explanation on how it works. You are a great teacher, paying attention to the content you're communicating. It's very fun listening to your videos. Thank you very much again for sharing your knowledge with the world.

[@ArcanePath360]

1 Question: Where have your videos been all my life? I've always wanted to learn electronics but there is so much junk on the internet with poor guidance. Your videos are so easy to understand and the knowledge gleaned from a single 10 minute video of yours is worth hours of normal research and headaches.

[@lilliampumpernickel9916]

this is so true, i just found this channel

[@kayodeoloruntola9032]

you guys are so fantastic keep it up

[@johnlbales2773]

Same here! Thanks Afro! U R Awsome!

[@emamsajid]

KAYODE OLORUNTOLA k

[@frankdavidson9675]

you can buy books on line teaching basic elec and eletronics very basic but good ground work

[@jimc52]

This is an EXCELLENT video. Thank you for being so organized and informative! Showing the specs was especially helpful and talking about Dropout and Efficiency...just great!

[@michaczarnocki181]

i like your pfp

[@kevinreid3529]

I've enjoyed playing with electronics for over 45 years & these are great refresher videos. Thanks for sharing.

[@sachin9977]

Your narration is wonderfully clear. Never boring nor over the top.

[@golastname7686]

Thank you. The concepts on diodes through voltage regulators are mentally-sequenced so very well. It's motivational since it leaves you wanting to do things just that much better for just a few pennies sometimes.

[@mxcollin95]

G O'LastName Well said! I wish this dude was my electronics instructor or had a full electronics video coarse available! I'd buy it in a heartbeat!!! As always, great job afrotech 👌👍

[@mxcollin95]

Whoops...video 'course'...I meant to say.

[@KrisKasprzak]

207 people have no idea what and outstanding video is. Thumbs up from me.

[@Afrotechmods]

+Kris Kasprzak Thanks bud!

[@Grenplen]

+Afrotechmods Hi! I have a Alpine 4-channel amp. Chan 2 is out.No sound But when I incresed the volume all i hear is cracking distorted sound. I opened the amp up found no burn Mosfet. What could be the problem? Any help is appreciated. Thanks!

[@talahhussain2867]

+Bouboune The problem is that or amplifier output wattage is higher than the wattage of your speakers

[@iprofessionalamateur]

its gone up to 253

[@Mindthegap720]

i love his humor and thats what makes the video more fun to watch.

[@Pascal_Robert--Rc_Creations]

I've discovered that if you put the load between the input and output pin, you can use it as a voltage substractor, usefull for a cheap gauge indicator for 12v batteries

[@VoidHalo]

To this day I still use this configuration for my 7805 power supplies for TTL circuits. A very useful video if there ever was one. Thanks very much for taking the time and effort to make this video and post it. Cheers.

[@lilliampumpernickel9916]

YES finally i found a simple straight forward tutorial!!! THANK YOU SOO MUCH

[@mikerama4466]

Very nicely explained, I've learned quiet a lot from your video. Thank you

[@marklowe7431]

I thought I've watched some good tutorial videos on electronics but these are steps up. Brilliant.

[@cri8tor]

Because of your tutorials, I have a much better understanding of electronics. I'm self-taught out of a desire to modify and improve my cheap Chinese tools. However, this has led me down the "rabbit hole". Thank you so much for your guidance.

[@SurvivalLilly]

How do you know that you need a 10mikro Farad capacitor. Is there a formular to calculate the capacity of capacitors to a different project for example?

[@Afrotechmods]

Capacitors can be used in tons of different situations and the formula to use will depend on the situation. 10uF for a linear regulator is just a generally good guideline value. The best way to find out the value for your situation is to google for the datasheet of the component you are using. It will either show you the formula or give you the recommended value.

[@cda32]

It depends on the regulator, the current draw, and filtering requirements which remove high frequency transients and voltage spikes from the load. The datasheet for the regulator provides the details for what smoothing and filter capacitors to use in various configurations.

[@rohitsimonskylarrohitsimon1608]

Survival Lilly

[@MarkTillotson]

Read the datasheet for the regulator you actually use, especially for low-dropout ones. Datasheets have specific information for the actual device so are the definitive source of information.

[@johnepperson8867]

Fancy seeing you here Lilly!!! Love your videos!!!!

[@motoservicepocivalec]

OK!!! I 'M SEARCHING THIS TWO YEARS!!!! THANKSSSSSSSSS !!!!!!!!!!!

[@loverboy-if3ox]

great vid! helped me immensely. great to SEE ppl helping others with their comments instead of being nasty towards them.

[@doviuxx123]

this dude made these kind of amazingly educational videos 8 years ago and in 1080p!

[@blindwillybrown]

brilliant video! learnt a lot very clear and easy to follow many thanks!!

[@aakashprasad114]

Woohoo! I made it! Thanks Afro

[@Afrotechmods]

🎉

[@aryanmishra5591]

Wow this was uploaded almost 9 years ago. Oh God people like you make the world a better place.

[@overlycranked8674]

such clarity in delivering the information is rare. Another great one

[@hrishikeshkalitaprojects1118]

Your all videos are superb, easily understandable. Keep it up!

[@jackhodgson]

You had me at, "Pffft! Progress."

[@kshitijkumar326]

This is the best possible short description of LM voltage regulators.

[@ser7ser7i]

I think i watch this again after almost 4 years and it is still gold, thanks

[@Albert.M1]

This is a very informative tutorial video. You are so clear in your explanations that I easily understood without breaking a sweat. Good work!

[@Afrotechmods]

Thanks!

[@anr1682]

Great video Thank you for taking the time to teach us. By the way the people who disliked this video are provably those who paid the $30 for a charger. lol

[@claystudiofx]

or maybe , they think that 10uf capacitor is a can of coke.

[@guitargodjoe3621]

This video was a revelation to me! Well explained and easily understood! Thanks!

[@sabrinaflipse7732]

thank you! we built one of these things in class today and without explanation of what we were building. thank you for being very clear what it does! :)

[@yassinabdi1385]

" i cant even show you one that catchs on Fire prfff porgress" hahahahahahah

[@RiaRadioFMHD773]

78s are positive regulators while 79s are negative.

[@i8tweak]

RiaRadioFMHD773 Thanks for the tip!

[@j5892000]

haha i see what you did there.

[@leonamferreira8053]

thx a lot!

[@vigneshwaran-1]

thank u

[@rishikkumar7417]

Can u plz explain the use of 79s

[@onmyworkbench7000]

Great video, I have used 78 series regulators on a lot of my projects and they have worked out very good, one of the things that you need to be aware of is when they get close to there dropout voltage there output can get very nasty. BTW I have that same Scope and I love it.

[@kieferonline]

Wow, I just learned something! What an excellent, clear explanation. Hats off to you, sir!

[@to6ko9913]

your voice is amazing

[@talhajhon8077]

Gay you

[@gilbertomartinez6981]

In another youtube channel “chinese cooking demystified” sounds like he might be the same person 🤔 very clear and informative tutorials in both

[@donaldfilbert4832]

I am confused about the function of the 0.1 uF capacitor. I understand a voltage ripple reducing circuit that uses two capacitors with a series resistor between the + leads in series with the current flow; but when you put two capacitors together in parallel as shown - they just add their capacitance. Right ? So isn't the circuit as shown the same as just one capacitor at a value of 10.1 uF ?? and how is 10.1 uF any different than a single 10 uF capacitor - really ? Thanks for any info you can provide !!

[@Afrotechmods]

Donald Filbert The 0.1uF cap is made with a different dielectric - it is a ceramic cap. The 10uF cap is an aluminum electrolytic cap. Ceramic caps work much better at higher frequencies. The 10uF cap would be useless at dealing with noise at 100+kHz.

[@donaldfilbert4832]

Afrotechmods Cool !! Thanks for the response and info !!!

[@kreynolds1123]

+Afrotechmods To the important in difference in dielectric is their ESR, Equivalent Series Resistance. In this circuit, ceramic's lower ESR helps the capacitor smooth higher frequencies.

[@DeLaCruzer11]

+Afrotechmods so the purpose of that 0.1 uF ceramic capacitor is to further smooth out ripple in the output cause by higher frequencies noise?

[@Evocatorum]

Correct. If you go back and look at the Osciloscope, you can see that there is some noise in the output voltage. The 10uF and the 0.1uF capacitors help to clean up this signal. If the original author were to hook up another probe to the board on the output side of the capacitors (or even just move the probe) we would see a near flat output voltage from the circuit.

[@sickvic3909]

2 mil. views in 6 yrs. and climbing, good going. Great delivery!

[@3xAudio]

Thanks this is perfect for what I needed to know when powering multiple arduinos and their built-in regulators. was afraid of frying some components.

[@CurtisEFlush5962]

@3:30 Its called retail.. Youre right though. There is a reason the middle man is slowly but surely being cut out.

[@MrGencyExit64]

Oh no, you can't show one catching fire? What would your channel be if all components were thermal regulated?

[@adriansebastiani8900]

Thank you so much for such an easy to understand and professional video. :)

[@mrtracyut]

Your explanations are so clear, awesome presentation man!!! Thank you.

[@Afrotechmods]

Interested in learning about wireless power? Subscribers can get up to 80% off my course Wireless Power to the People - Wireless Charging 101 on udemy using the coupon code "KZbin" www.udemy.com/wireless-power-to-the-people-wireless-charging-101/?couponCode=KZbin

[@bubblelaber4909]

man i am a big fan despite of the fact that i came across your channel last night. The content that you offer is best worth my time. i wish i could donate to your work but here i am trying to find my place in this world.But hey big shout out to you.Peace bro.

[@djtoddles8750]

0:29 Where do you source your Durasmells? The source I've been using stinks :)

[@iangrieve8805]

that is a truly excellent video. very clear, concise, and easily understandable. you have done me a service, thank you sir

[@TheCurlyburger]

Your Tutorial's, are a 'godsend'. Very Informative and so easy to understand, Clear and precise and in such a way as, even a beginner would understand. Your emphasis to detail, 'all and everything', makes it, an all the more an enjoyable process to learn electronics skills Theory. I wish my Lecturers' Could have had, the emphatic qualities that can be observed by, viewing Your Tutorials. Sincerest Thanks.

[@Daitomodachi]

Quick question. I know that some devices are trickier to charge (e.g. Apple Iphone from what I heard). Can you charge android tablets by supplying it with 5v or is it a little bit more trickier? Also it would be awesome if you could talk about switching regulators. They more efficient and can handle a larger voltage range than linear regulators.

[@wax147]

you can charge apple devices if you short out the data pins with a 50k ohm resistor. google it.

[@NordicDan]

3:30 LMFAO nice!

[@Purple431]

3:30 lol

[@someguyontheinternet-]

Lmfao

[@Purple431]

@@someguyontheinternet- haha lol

[@mobilecommando]

Great tutorial. Happy Thanksgiving. I'm thankful for smart people sharing ideas.

[@Flippy2k6]

built one of these last night, you sir are a legend.

[@amtpdb1]

Hi: I know that this is an old video, but I still have a question. When you already put a capacitor on the output, why did you have to add a .1uf ceramic capacitor also? Why a ceramic, and why so low amount and why not just up the 10uf electrolytic if you needed more. Thanks for your time and great videos.

[@enriquephan7729]

I have the same question, what would happen if there werent any capacitors? or If there werent one of those...

[@enriquephan7729]

So, they act as a noise filter? And the capacitance determinates the frequency they filter, right?

[@enriquephan7729]

Sebas Eu Thanks! I will do a deeper research to fully understand the topic.

[@deelan_]

+Kique Phan Razquin Without Caps The curcuit wont be very stable. Its like using an LED. When you have an Voltage of 4v, you can theoratically connect a LED direct to it. But its still better to use a Resistor. Also i heard, that the Efficency suffers without caps. But if you dont care about Efficency, you can use it without caps. But i think everyone you will ask, will recommend you to use an 78xx with caps

[@cipher-1]

AntoniRockReykern I think this is for reject the noise at 50 or 60 Hz. This is why to use 100nf capacitor

[@thoughtyness]

How do you calculate the capacitance needed for the three capacitors?

[@petermcarthur7450]

You look up the minimum recommended value on the datasheet.

[@theSoberSobber]

Thoughtyness C=I*T/V

[@Team-lv3dc]

Thankyou. drop out voltage is exactly what I was looking for an explanation of. I love you.

[@thersten]

First video i've ever seen of yours. Excellent stuff. Subscribed.

[@dustdevil317]

Sadly, everyone always discusses 'USB chargers' and things of that milliamp ilk, but they never discuss when your input is 15v+/-2v ripple and your current is 90-amps. What do you do about actual amps? You can't just ignore 180 watts of dissipation, and you don't want that 'big as a buick' heat sink issue. What then, relays?

[@TheSuraj03]

I think they use multiple regulators with a combination of relays and forced cooling..

[@PHRANQ2K2]

Can you use just one regulator to control the base of several high current transistors? In a H-circuit arrangement perhaps?

[@dustdevil317]

Actually, there are more high-amperage regulators than most external-appliance milliamp regulators. It's call 'your car alternator', and there are hundreds of millions of them worldwide. Sadly, since not one single video was on KZbin showing how something 12v and over 5-7 amps was regulated, I was lucky enough to get a schematic for an automotive regulator to see how they were handling the 'high amperage'. Quite simple, actually, and most do it for less than $20, case included.

[@sth128]

For high current (hell, any current really) applications you'll want to use switching voltage regulators instead of linear ones. The chips are super cheap and the circuits aren't really much more difficult, especially fix voltage ones. Look up buck-boost converter for voltage regulation. They are meant to regulate over and under voltages.

[@HappyBeezerStudios]

That is actually a good question. Looking for an air compressor that runs on 12V 7-10A but need a converter that runs off the wall. so those high loads are there.

[@kylelafountaine8164]

Does it matter what capacitor (electrolytic, film, ceramic) is used?

[@haraldkongen]

Kyle LaFountaine Yes

[@kreynolds1123]

+Kyle LaFountaine yes, and no. That depends on your voltage regulation needs. In this circuit, ceramic's lower Equivalent Series Resistance helps the capacitor smooth higher frequencies, while the electrolytic capacitor is cheaper to provide the farads to smooth out lower frequency oscillations.

[@naggorski]

Awesome video! Very informative yet not overwhelming. Thanks!

[@GeekMustHave]

Google is my best friend, one of my mantras to my students. Nice presentation. Keep broadcasting!!

[@kristsjavalds3545]

Durasmell?

[@johnnysharp1970]

Krists Jāvalds Duracell "rip-off"

[@proto7999]

and I thought that it's a bipolar junction transistor all these years XD

[@syaugi5748]

Believe me, you're not alone

[@wntu4]

Love the quick shot of Best Buy as you mention not getting ripped off. I avoid that place at all costs short of utter "must have NOW" desperation.

[@dickda1]

Very concise. Thanks. Glad you mentioned the minimum dropout voltage.

[@lastflightofosiris]

I'm so furious that i didn't understand the 0.1 micro farad capacitor. Why is it there? I read most of the comments, no one bothered to wonder. I just... can't... Why? What am i missing?

[@Afrotechmods]

The material used to make the 0.1uF cap (the dielectric) is ceramic, which is different to the dielectric of the 10uF cap which is an aluminum electrolyte. This means the two capacitors have different performance at different frequencies. The 0.1uF ceramic cap is best at filtering out high frequency noise whereas the 10uF cap will be useless for that.

[@luongmaihunggia]

Write "I will use google before asking dumb questions" 100 times for me.

[@MarkTillotson]

Generally you don't need the ceramic cap at the regulator, as each chip you're suppling has its own ceramic decoupling capacitor close to its supply pin. Yes the ceramic cap will handle events on the timescale of nanoseconds which is the speed of logic chips.

[@johnepperson8867]

There are NO "dumb" questions!

[@JBattler]

hmmm not sure what the difference is in asking here than asking google except that asking it here makes more sense. The only dumb question is one that isn't asked or is asked despite it being answered in the article in question. The perception of "dumb" is based on level of knowledge when encountering a piece of information. A good well-thought-out tutorial will not leave these kinds of things hanging. 'Tutors' are usually (not always on youtube unfortunately) well versed in their topics and can easily forget what watchers may or may not know so can easily miss/skip bits. This is a common problem for us beginner learners in any field. Otherwise this guy's videos are great!

[@bruhdabones]

What screw do I need for that?

[@DavidTurnell]

+Bob “bobdabiulder” dabiuld Anything that gets your nuts off - come down to Brazil and try a tranny.

[@creepingnet]

Best explanation so far, now I can start working on those BBD Delays, Echos, and Choruses without frying my BBD Chips.

[@bob-ny6kn]

Still relevant many years later. Thank you.

[@deelan_]

What? I have a voltage regulator module that regulates to 5v usb with max. 3A. I've connected a 9v battery to this and my TABLET. The regulator didnt even get warm and my Tablet has charged as fast as is charged at its 2.1 A power Supply.

[@Mixbag]

LM1084 and its setup for 5v using resistors. my voltage drops from 5.20v to 3.30v when i connect a 2A load on it.. anyone help me solve this ? my power supply is 12v 20A and input voltage stay at a constant 12v and iv tried 2000uf cap on the output but still voltage falls iv used 4000uf also no change...and mobile phone stops charging under 5v

[@PunakiviAddikti]

Mix Bag Unless you're using an adjustable linear regulator, you can't set the output voltage using resistors. You need a 5 volt regulator with no resistors for 5 volts. If you need more power (aka more amps on the output), get a powerful buck converter.

[@ThatGuy-nv2wo]

So if I put in 1V then I get 5V out and dissipate minus watts! I can create free energy AND a fridge!

[@syahrul9282]

Lmao

[@HappyBeezerStudios]

Just if that woud work, the current would just go into the otehr direction :D

[@dalenassar9152]

I think the small capacitor (0.1uF) works best for decoupling if placed closest to the regulator. THANKS FOR THE SUPER VIDEO!

[@hardtofind66]

GREAT ! Thank you for touching on each detail that i wanted to ask a Q about, simple, Obvious even, but not to me. I going to look through all of your videos .

[@suddencucumber5994]

2:31 - how do I use google?

[@traianima]

in order use google you must make a 12 volt circuit with 2 transistors and a 4 diodes and a stepping motor, then just connect it at the computer. If you don't know how to make the circuit just google it.

[@sonyobright2106]

lol

[@hycron1234]

You jab a metal fork into a power socket. No seriously don't do that. 🙄

[@renzevenir4853]

I don't like linear regulators

[@mohamedtaha2025]

why?

[@electronicasaneesh82]

@@mohamedtaha2025 rue it waste lot of power . use dc to dc converter. see my videos

[@skirnir-atf]

@@electronicasaneesh82 But fore audio LINEAR - best voltage regulator. DC-DC convertors produce a lot of noise.

[@goaliedude32]

You are amazing. I'm in love with these videos!

[@geek9642]

Thanks for making the video, just helped me build one and fixed a canbus issue on a car 👍

[@yoyojoe5395]

clean, clear, simple, 10/10 - thank you

[@supercheekykiwi]

This is a brilliant video. thanks so much. explained in simple terms to help with a project

[@robertmeyer4744]

great job. these regulator is all over in electronics. simple good ones have thermal shut down. over current. some I buy are LM340T-XX or LM340K-XX .same as 78XX .

[@bobharrison9620]

Old Vidio but just what I needed and just in time. Good teacher. Thank you Bob

[@kapilsoni5713]

Simply brilliant piece of information......thanks for posting such a nice video.

[@daaronson35]

This is perfect! I'm making a bike charger for my cell phone and this is the perfect circuit to use. Thanks.

[@castro1780]

This is such a good video on explaining the basics of a subject, and then applying the knowledge in a practical situation. And lol, even the dollar store rips you off on charging cables, ebay is the way to go. You can find just about any cable for under $5

[@hightime766]

You are great bro... Your explanation is outstanding....

[@masterwrench4252]

Wow bro! That was cool, simple & made sense...please do more!

[@astorina]

Great teaching and straight to the point. Much appreciated...

[@Hydrogen4Health]

I love your humor. You have made me laugh out loud several times.

[@simbo9915]

I learned so much, this was really helpful. Thank you :)

[@christopheek]

I don't understand the 251 people who disliked this video. It is as elaborate and as clear as can be. One question though, what are the input and output capacitors used for exactly? Also a question that is slightly off topic, I am trying to build my own Power Bank to charge my cellphone and intend on using either rechargeable batteries or disposable batteries. I'm not very familiar with the way batteries work but assume these batteries do go empty, does that mean their voltage will drop from, say 5V, down to 0V, thus meaning I'll have to get a low-dropout Regulator? Thanks!

[@rameshtripathy5978]

Excellent description & very helpful too ! Thank you so much Sir !

[@hugoperozo4895]

Thank you. Well explained. Thank you for taking the time to make the video.

[@brad4792]

You're one smart guy Afrotechmods.

[@Prence]

Thank you, I was wondering what I would need to turn a 7.2v NiMH battery into a usb charger for my ipod touch and cell phone, and you showed me. Thank you so much.

[@WayneTheSeine]

Excellent instructional....thank you. It helped tremendously.

[@milanm5776]

Thera are 350 electrical engineering students at the moment in amphitheater at the moment and our professor played this video for us so we can learn more about voltage regulators.

[@Afrotechmods]

Woah. Which school was this? Post a photo!

[@milanm5776]

@@Afrotechmods Its "Electrical engineering university Nis"

[@Afrotechmods]

Thank you

[@patricklawless6597]

Great video! Very informative and helpful. Thanks for making it!

[@jagdishnawal4080]

Excellent explanation - keep it up - looking more such informative videos

[@rotorcraft68]

Simple. Concise. Perfect. Thanks!!

[@ericscaillet2232]

Precisely 😉

[@sameobiggy]

Geat video! Thanks for breaking it down. I was blind but now I can see.

[@renekenshin6573]

Awesome tutorials as always ^^