I cannot believe the amount of work you put into your videos. The animations must take forever to make. And then you actually built an active load to properly show how it behaves instead of just connecting some resistive loads. Simply amazing and much appreciated!

I have a Master's degree in EE, and I learn something new from every video you make. Fantastic work, keep up the nice animations :D

i know these animations are a lot of work but they're really elevating your explanations 🧑‍🍳💋

Great to see you after long time... please continue because your explanation is very unique

Wow, what a truly educational video. Learnt so much that others just dont teach. Perhaps we should rename you "Carlsberg". If Carlsberg did Electronics videos.......

Wow ! I will come back for more.

Subscribed to you like a year ago and never got around to watching anything til now. This is fantastic!!! I'll be binging your videos this week, you are really great at using accessible language without leaving out critical info. People like you are great resources for folks like me, been into it for a couple years but don't have much education and havent been in school for a decade so it's not easy plowing through textbooks. Love the animations too, I really appreciate the work you put into this. Keep it up :)

This was an amazing video! Really loved the effort put into the animation! Great job!

I appreciate and respect you for showing us the "how & why" that goes into the power supply design. I'd really, really like to see that "Proper lab bench power supply with all the bells & whistles" that you mention at 1:42 !

what you teach our college professors can't explain at all with such a ease ,Thankyou so much for sharing your knowledge with all of us , love Respect from INDIA

Seriously awesome. Especially how obvious it is that you’re enjoying yourself. Puts a smile on my face and new thoughts in my brain

One of the best resources on the subject that I've come across- thanks for this excellent video!

Brilliant job, and amazing explanation.

I've seen probably a dozen videos building the wall-wart Eurorack power supply. Yours is the first I've seen that gets it right - everyone else makes the assumption that you can draw some large fraction of the transformer's rated current as output current. Bravo for setting matters straight! Most of the clones of this design I've seen in other videos would have exploding caps or a smoking power transformer if operated even close to the claimed load. With a linear regulator downstream, you can treat the load as a constant-current sink for a slightly simpler calculation. Linear regulators don't consume more than a tiny amount of current for housekeeping, so input current=output current is a decent approximation. Also, you have to watch out for the capacitor's ripple current rating - the capacitive-doubler design is often pushing close to the limits for cheap caps. (Your two-cap design is much safer, good job!) At some point I'll probably make my own video about this topic (and cite yours in hopes of sending a minuscule amount of traffic your way) and put up a Python script for designing such a beast. (I've got one right now, but it's "user friendly" in the sense of "if you're my friend I might let you use it"). I'd get a little more into what numbers to look for on the data sheet, I think. My back of the envelope for a quick-n-dirty +/12V power supply started with a 14VAC, 40VA wall wart, designing for an output current of a third of an amp. Designed with Schottky rectifiers (SB2405 is what was on hand, if memory serves) on the input, but 1N4004's for the protection diodes. Calculation showed 920 µF to maintain regulation, so went with two 680 µF on each rail (didn´t bother with that 1R resistor in between them, it doesn´t actually accomplish all that much). Calculation showed about a 37° (0.65 rad) conduction angle, a reasonably gentle ripple current of 565 mA per capacitor, and an input current of 1.36 Arms per rail (2.72 Arms total), just under the 40 VA rating of the transformer. All of these were for a 60 Hz power line because I live in Yankeeland. Ludicrously inefficient, but functional. The wall wart gets kind of toasty. The capacitive doubler has a deservedly bad reputation. Conclusion: Buy a switcher. Designing your own switching power supply is a PITA. I know. I've done it. Also spend the $30 or so on an RCD-protected line cord because I can't figure out how to put a proper safety interlock on the rack and there will be musicians' fingers inside, wiring modules. Use a commercial IEC power entry module, and insulated spade connectors, and a safety cover on the terminal block, and all *should* be finger-safe, but I still don't trust musicians with mains voltage - or to remove the mains voltage when working on the rack. Plus, on gigs, there's too much chance that someone will spill a drink into the skiff.

Outstanding tutorial!

So this is basically very similar to my Eurorack Powersupply I built a year ago. I'd like to share some optimizations I did, as I wanted to gather as much current from it as possible. -I've started with an 11.5V halogen transformer 50VA which is not ideal at all, but due to optimisations, I can draw 500mA per rail continuously! -The rectifier diodes are beefy Schottky diodes. -I used no serial resistors, so there was no further voltage drop, but this means the transformer and diodes are more stressed. -For the linearregulators, use LDO (low dropout regulators)! So you don't need as much headroom, 2V vs 50mV makes a BIG difference. -Adjust the filtering capacitors to optimize between ripple voltage and inrush current. -Use a large Heat sink. At full load, you have to dissipate quite some power in the regulators.

This is a concise and intuitive lesson in every aspect of building a power supply. Amazing visual explanation of the diode's and capacitor's mysterious actions in this circuit. Great work!💯💯

Great series 👏

Instantly subscribed your channel because of the quality content that most mainstream youtubers dont provide... Hats off to you sir.. keep it up🎉👏👏

Phenomenal explaination.👍

Thank you, I learned some new things! A note about the 2 volts that you specified for headroom. Two volts is the minimum to prevent drop out. Three volts is the minimum required to allow the regulator to achieve its minimum ripple factor. Read the fine print in the data sheet and application notes. Also, read the testing perimeters that the manufacture uses to achieve the best ripple results, for marketing bragging rights. You will find that they use a minimum of 3 volts of extra headroom. HTH. Cheers!

This is a monumentally amazing video.

You have done a super job. Ask utube to provide a soft button so viewers can make a donation without said donation becoming monthly. Some channels have this set up to buy the creator a beer, coffee etc.. Some viewers can not make regular Patreon payments but, can make occasional expressions $ to reward your work.

Excellent video!! I have an associates degree in EE and remember understanding ripple voltage, but didn’t quite understand why it was occurring. You cleared it up for me in this video. The draw of the load. Thank you!!

Superb explanations and animations. Great work.

There are variable 78 and 79 series regulators. They have a GU(1C) suffix in a 4 terminal power package. The output voltage specifications between the 2 polarity types do not match however with the 79GU regualators offering a slightly greater voltage range at the low end. The 78GU1C is often used in dc servo motor control for a constant speed. Come across them in audio applications in tape decks etc. They have been somewhat superceeded by the LM317 and LM337.

Dude you are amazing.Keep up the good work ❤️

Thanks professor !

I did this the other day for a extemely hard to find analogue video power supply!!!! I combined 3 wall warts, two 7v and one 5v. Connected the grounds together of 5v and 7v and the positive of the other 7v to the ground to make +7, -7v, and 5v. I then probed the connector and made an educated guess about which one connection was which and it worked!

I have never seen a diode arrangement like that for a dual voltage output linear regulated supply. I always have used full wave bridge rectification if the transformer has a center tap. However, the more popular general power transformer output winding design for dual voltage output is to have two separate equal voltage output windings. Some transformers are wound so you can actually have two separate full wave bridges one dedicated to the positive supply and one for the negative supply. This has the advantage of spreading the heat out at the cost of two smaller bridges versus one large bridge. With the two "floating" supplies approach you can choose where to locate the single point star ground relative to the loads you are driving, like an audio power amplifier. This will prevent mixing of different rail currents through a long common ground impedance.

Thank you for making this so easy to understand. You would make a great teacher. Looking forward to the next video! BTW cool shirt

I know I'm preaching to the choir here, but damn, these animations are so good!

That looks like a Hinton instruments PSU in the thumbnail. Would love to get one of those in my new case. Great vid btw.

I would describe an diode in forward bias as a 0.7 V voltage source, not a short. A short means that both terminals have the same voltage. What's important is that current is not limited (like in an voltage source).

Watched this video. Instant subscribe.

i wish these animations were more coomon, it helps understanding the circuit like A LOT! I whis i had these in my study materials.

Thank you

I enjoyed that! Thanks!

Brilliant!

Your channel is soo good I hope you can get back to posting some new videos soon, I believe you are busy but seeing that "proper" power supply video one day would be amazing, cheers! :)

Great video. Thanks

Please, make a lab power supply design. It could even be a course like some Phil's Lab videos on KiCAD with more detail on paid course or for Patreon. I have seen few channels playing bringing up the idea, but it's never done or left not finished. There is plenty of videos with simple power supplies - from just chopping of leads of a computer ATX power supply and attaching banana plugs one way or another, maybe adding some Chinese voltmeter ir DC-DC converter module. EEVblog Dave started a design years ago, but it tracked different way to a pocket supply, that got wery advanced but wasn't finished. It is nowhere else to be found - how to make custom LCDs and heatsinks. Interesting. But it would be more practical to understand the necessary principles, what to be cautious about and build a real bench lab power supply. With some bells and whistles added. But I believe I'm not the only one who has done a fair share of simple L78xx/L79xx and L317 circuits, but would like to make a proper lab/bench power supply but lack the skills. Chinese modules are useful, but you don't really learn much by wiring them together and they have significant EMC and ripple drawbacks. Thank you for this video, circuits shown are simple and known, but you shared a good amount of knowledge and details to be aware of, many others skip over or probably don't know themselves. I think microreps and Signal path had idea of a lab power supply, but it hasn't came to life.

Sir awesome video explained in a simple way , when is your next video on same topic i.e. how to design power supply in detail , explaining the working of every components , why it is used. Waiting for your next video . Thanks

Solid Job on that. Looking forward to more videos Some stats: The spoken duration of the video is: 1263 seconds - 50.85463 of silence 4826 total words spoken in HMS: 00:20:12 of total time: 00:21:03 excluding 00:00:50 silence 238 de-silenced wpm

This is a fantastic video, so thanks for that. But I've got a question that occurred to me that I'm hoping you can offer an opinion on: Is there anything to be gained as far as maximum current output by using a transformer that outputs a voltage higher than than the regulated output, e.g. using a 15vac xformer to produce +/-12v? Using the same assumption that you did for 12V, i.e. minimum ripple V = 12+2+.5+1=15.5V, and assuming the max ripple V for a 15V xformer to be 20.5V gives an allowable ripple = 5V. Assuming a capacitance of 2000uF and rearranging the equation @ 12:35 to solve for Idc gives 600ma. (I used f=60Hz for US power...) Is this a reasonable assumption? Or is there something really basic that I'm overlooking? Google seems to be pretty useless when it comes to the specifics of charging and discharging of filter caps in linear power supplies...

So nice

THE BEST video on power supplies I've ever seen. I will say... you mentioned that this video is meant for a total beginner. I am a total beginner, and more than 50% of this was all WAY over my head. BUT... I have kind of learned to expect this. I realize that "beginner" can be very relative to someone who already knows electronics. Maybe you meant... "Not new to electronics, but... New to power mgmt." or... "...new to audio power..." Either way... Brilliant video. I'm going to support you on Patreon!!!

I think in the schematics you forgot to add the negative voltage regulator LM7915

Great video thanks: I have a 220/24vAC transf which I'd like to use for +/-15vdc- can we take same design and just modify resistors/capacitor values?

Thank you, wish I'd seen this years ago. I've built a couple of these--more crudely than you described, though they seem to work just fine. More recently I used a charge pump (icl7662) and it seems to sound fantastic also (used with preamps for a guitar and a spring reverb driver). Is there any reason one might want to choose between methods for split rail?

Thank you very much . I have a question please. From your experience, what are the factors that damage the double rail operational amplifier IC? And I have another question. For example, I forgot to provide it with the supply voltages, and at the same time I provided it with voltage at the two inputs. Will it be damaged?

when the world needed him most, he vanished.

8:38 22 VA means 22 Watt right? So 22 VA Does it mean multiplying input AC 220 voltage by the input current?

It was really cool to see the oscilloscope traces for this. I've seen the diagrams with ripple current etc. loads of times, but somehow it makes it a lot more real to see the traces as you adjusted the load in real time. Very nice to see how in practice it exactly matched the theoretical behaviour!

Question. If i don't have a power transitor, can i use a power mosfet? How about doing a Darlington circuit with a lower power transistor?

I was actually hoping that this was about designing actual transformers, since there seems to be a lot of money to be saved for many electronics projects if you wind your own transformers. Also, single voltage supplies are very very common these days. I've got a ton of 5V, 7.2V, 9V and 12V powersupplies lying around, just from all of my electronics gadgets. It would be nice to power my audio electronics projects with those, but these projects usually require a positive and negative rail, so what is the optimal way of creating a split dual supply from a single supply? A voltage regulator seems to be the easiest solution, but not exactly the most efficient solution. Would be nice with something more efficient, but still very stable. Buck converters perhaps?

what about smps? will there be a video covering such topic?

Where did you buy your ac/ac adaptor from? I can't seem to find any! (im also from the uk)

i love your videos and am slowley begining to actually understand themm.... i am beggining to repair ... audio amplifiers ...you know how sometimes you need these symetric powers uspllies ...and you dont havea center tap transformer so iwas looking for an alternative circuit givin only a normal transformer ....thisis very usfual and the math is cool to ...but can they handle a serious current draw? because its happend to me that i i overheat the voltage regulator when in a audio circuit

Something that may not be obvious for a beginner: A linear regulator produces heat according to the excess voltage that it has to "burn". E.g. with a capacitor voltage of 19V and a output voltage of 15V, running at 400mA, we will burn (19V-15V)*0.4A = 1.6W of heat. Your regulator will need a small heatsink attached to it to be able to dissipate that heat.

Merci.

Likewise, I was not able to find the follow up video you mentioned.

I want to know how to build a +/- 12V PSU powered by a lithium battery... i.e. battery powered synths... But I've not found any good videos on the subject. I know that it involves a floating ground but, I'm certain there are lots of little gotcha's involved you need to plan for and am just not sure how to proceed.

класс))) спасибо!!!

Had to sub again. Satan needs to keep his Meat Gazers off my buttons, and let me control the flow of information I receive. On a plus note. I like the illustrations you’ve added to your explanations. God Bless.

If you add too much capacitance you can blow your input transformer. It's a balancing act.

What kind of power supply is this? Linear power supply? The content is excellent, please make a video on how to make a SMPS (Switch Mode Power Supply).

Those ac-ac transformers are really hard to find in me experience, especially for European plug 230V. Where did you get yours? Also 300mA don’t sound like a lot. Definitely will be looking forward to your next power supply video

The capacitor is it polarized cap type?

Hi hope you are doing well and safe..it's been a long time

I'm a bit late to this party with this one, but was wondering about the capacitors on each side of the 7815/7915 regulators. Your schematic shows all 0.1uF, but all the 7815 data sheets I have seen show 0.33uF and 0.1uF for the 7815 and 2.2uF and 1uF for the 7915. Clearly this has not caused any problems for you, but why would the chip manufacturers specify four different values of capacitor if one is enough? Does it make that much difference?

I wish I could like more than once1

Go into the maths and theory! There are too many simple and dumbed down channels that shy away from showing the actual physics and engineering --- don't fall into the same trap!

Why choosing frequency to be 50hz instead of 100hz because after rectification the AC frequency double

This breadboard got realy hot between 15 and 20? (just for the algorh...)

What's this guy's name? I need to cite him in a thesis.

Are you ok? You haven’t made a video in a very long time.

10:18 poor power supply getting spanked over and over again…

Got you over the $200/mo Milestone! 🦾🤖