One thing you forgot to mention is certification. Generally, any device sold in North America that uses high voltage inside has to be UL rated or equivalent. By keeping the power supply outside of the device, you can re-use the same UL-rated power supply with multiple devices without having to get each one certified individually.

I remember when I was in middle school. One of the pins in the power adapter for my laptop broke. So I got the brilliant Idea to cut the cable off the adapter, and the plug of the cable for the power adapter's power, then spliced it together. I took care to tape the splices individually with painter's tape( because I didn't have electrical tape) then again with packaging tape. I plugged it into the wall cautiously. Nothing happened,( I must have done it right!) Then with the greatest sense of accomplishment I've ever felt at that point I went and plugged the other end into my laptop, there was a short pop, then a loud ass pop that rang through the house, and the power shut off in both mine and my sister's room. My family thought it was a lightning strike, I let them believe it.

To convert ac to DC you need a FUUUUULLL BRIDGE RECTIFIAAAA +1 if you know

0:33 Crime investigator : What was the murder weapon? Police : A power adapter

LMG: Linus were out of video ideas Linus: *looks at ground Linus: that’s one thiccc power adapter LMG: were on it

Just make a bunch of FOOOLLL BRRRIDDGGEEE RECTIFIERS

#TLDR Reasons why they're big: - Semiconductors are not entirely efficient (Look up PowerMOS, GaN, SiC) = Heat + Heatsinks - Isolation from Primary Side/Secondary Side (UL Regulations) - Bulk Caps & Transformers

actually its not the conversion from ac to dc that is the problem. its voltage. the biggest part of an adapter is the transformer. bridge rectifiers can be really really small.

That's not why they're called switching power supplies. They're switchmode power supplies. They contain a control chip that turns on and off at a much higher frequency than the utility supply. The high frequency means that a smaller transformer can be used, saving space and money, as well as reducing waste heat. The control chip monitors the output voltage and adjusts it by altering the switching. The switching is why some phone power bricks make a whining noise, and it's pretty much the same reason for the coil whine you get from some graphics cards and motherboards.

I backup/transcode film cam data on location. Often Im stuck in a van in country, in winter 1-3am. I put the adapters under my feet to keep warm.

This video is so wrong. Switching power supplies are called switching because of the way they work. ALL switching power supply convert AC to DC in the initial phase (in a 220V system the DC rises to something like 400V). Then a switching circuitry sends current impulses (15KHz - 50KHz) into a transformer. Those impulses are driven in a way that the output from the transformer is exactly what the power supply is designed to output. This has nothing to do with the fact that they can adapt to 220 or 110V outlets (actually not all switchers can adapt to this automatically.. a lot o them still has a 220/110 selector). And regarding the integrated power supply (like your example... the monitor) is still switching power supply. TVs also has switching power supplies.... consoles... basically any device used today.. has a switching power supply.

I spent 5 years in the seventies in a factory making switching power supplies for mainframes. These where about 24 inches long, 8 inches wide and about 6 inches tall and they weighed a huge amount.

Just because transistors are getting smaller doesn't mean inductors can get smaller too, which power bricks need to regulate voltage. Some things in physics just aren't capable of being shrunken down to save space, in the name of power efficiency.

"Smaller, lighter, more portable" I wish that were true for smartphones...

Linus. I really like your videos, but this video has some cringeworthy explainations. LIke many people already commented and explained in detail, a switched-mode power supply is not called that way because it switches between different mains voltages. Guys with electrical engineering background are screaming while watching this video :)

Nice video. I found it both entertaining and educational. I like how you simplify a concept in a way that the general population would understand without knowing much about how electricity works. I also really enjoyed the outro for this video it was pretty amusing.

1:40 who hit this guy

Could you (if you haven't already) do one over building your own pc, like specifically talking about the components are, what they do, and which ones you can trade out (ex: ssd and hard drives), as well as what you have to actually have to make a PC that turns on and runs (like the absolute basics of a normal everyday use kinda PC)? If you've already done it I must have missed it. And I love all of yalls content it's really helpful and informative!

Now I understand why my brick adapter is so bulky. It's because I can fry eggs on it.

3:11 Hey look, that's the kind of laptop I have

Do writers proof read scripts? Linus looking silly a lot more lately using incorrect terms.

My power adapter gers so hot that it's radiating warmth could probably power another computer.

As the GaN switchers come out, the efficiency can go way up.

they never used linear power adapters, they use 50Hz tansformers, and then after rectification linear voltage stabilizers

I’m an EE with 20+ yrs experience. Good video for a basic overview! Some of the factors that drive size are: 1: Safety (there are physical space requirements to keep the dangerous AC power away from the relatively safe DC power you might touch). Also we have to have minimum insulation to prevent things from accidentally wearing and electrocuting you. 2: noise. You touched on this. There are two kinds of noise Radiated (wireless) and Conducted. Radiated is dealt with by proximity (which you described), shielding, or careful filtering at different parts of the power circuit. Filtering almost always adds size and reduces efficiency (which makes heat) and is a difficult balancing act. Conducted noise comes to play with regulatory compliance. You don’t want your device making a lot of electrical noise on the AC line that can mess up other devices. Govt agencies (FCC, IC, CE) have limits on this noise level to make sure we all play nice. Again that means filters which can be quite large. The technology has improved a lot and today’s components are far better; however, there are some fundamental physics limitations that determine size of these parts. That being said, there is a lot of innovation and investment to produce more efficient and small power adapters. New methods are already drastically reducing the part count and complexity which makes my job as an engineer easier to meet challenging size and packaging desires. Again, great video! Thanks!

Was that linus's kid at 1:25 cause honestly that's something he'd do

Hey Techquickie! I really like your videos. They really help me understand different aspects of tech. I've watched quite a few of your videos and don't think I have ever seen you talk about an EEG Machine. Could you do a video on EEG Machines and how they work? Maybe if through tech like this, reading minds could ever happen? I think this is a very interesting topic and would love to see a video about this on Techquickie. Thanks.

That ending was the best. 😂

The External Brick of my 250W Dell Precision 7720 is half the weight and half the size of the 230W brick that came with my Dell XPS M1730.

Just enough info for most viewers to gain a better understanding of AC/DC conversion. Yes there are some holes but this isn't a power electronics seminar. Good work. I approve, and I design these switch mode PSU for a living.

1:05 :O Linus resisted the urge to snap when pointing at the corner!

Love the outros on these! LOL!!

Apple: I’ve never seen this man in my life

Just use a FULL BRIDGE RECTIFIER

The thumbnail is funny please make more thumbnails like this 😂😂😂 the power brick with fire and linus that wants to survive the attack 😂😂😂

The pulseway add before the video was epic !

In other news, transformers are big.

It annoys me when people with little electrical knowledge explain electrical subjects.

This is still an area that tech companies can push. Apple doesn’t use external power bricks in their iMac’s or Mac Mini’s, and their laptop bricks are still fairly small. As phone chargers need bigger and bigger power units, and laptops chargers are increasingly becoming lower and lower wattage - I think we’ll see a point where the units combine and we just use USB C cables directly into the wall. Apple is almost there at the moment in that they recommend their 29 watt wall charger for both the iPhone and one of MacBooks, but hopefully this becomes more widely used by other manufacturers as well.

Now we just need DC outlets in our homes :p

"You can use those things as a murder weapon" Hehe yes.... yes you can hehehe

But who's really flying your plane?

I remember my train set transformer which converted 240V to 12V and was the size of a shoebox and had an audible hum. The modern mobile phone charger has a power supply about the size of a mars bar. I was told the 240V goes through an oscillator circuit to say 20K Hz which means the transformer can be really small. My trainset transformer probably ran at 50Hz.

Where was you when I needed this in science class 12 years ago...

smartphones could run on ac fine, its just that converting the line voltage requires significantly large isolation and comes with significant heat losses that you just dont want in a small device. I also dont want to imagine the port and cable required for that. It would be large and possibly dangerous.

Should have mentioned the ac/ac transformer block, which usually contributes a lot to weight and volume

Plus points for using a full bridge rectifier schematic on the AC-DC animation. However that's not what switching power supplies are. "Switching" refers an on/off action made by the circuit to regulate the voltage. Also thinner/smaller components does not necessarily have too much resistance, but they do have lower AMPACITY, and that is why they have to be bigger.

I had a Compaq 486 laptop with integrated power supply. It just needed a figure of 8 cable to plug into the wall. Guess they have. bad experience I think there were more models with that feature from Toshiba if I'm not mistaken.

So why don't we instead build in AC to DC converters inside of our houses and just have them live in the walls or the basement or something? Seems like a better idea.

3:55 I think the wording you chose there is very poor to the point it is wrong. A power supply doesn't consume 1000 watts or more, it supplies, or converts, 1000 watts or more. A supply does not consume power, the components attached to it do. Also, I believe your destinction between linear and switching power supplies wasn't very good. I don't feel you quite got the point across how a switching power supply differs from a linear one.

0:20 that laptop is the one that i have, just with an extra USB port. Its a lenovo ideapad 300 series and the power adaptor is actually quite small for a £300 laptop

You have given one of the best reasons for the updating of our current main panel here in America [and Canada] to the European DIN rail style. Since this is an industrial and more robust system. Our current system is behind, a good 15 to 20 years to the European. Take for a example the common light bulb… it has the LED’s and a small Converter Driver housed in. While they could be a few in the main panel doing the job to drive the whole house [or units per floor]. Bring in down the cost and usage of current. Just one example. The whole wiring in today’s house needs to be redesign; period. Starting at the plants, houses main panel and so on.

Nobody ever used linear adapters to go straight from AC to DC. They used transformers to step down to low voltage AC and then used bridge rectifier + linear regulator to get DC. The huge heavy transformer was the problem with that.

What about silicon vs gallium power supplies?

I heard, that we are slowly reaching the "limit of silicon" in computerchip performance. A video about why that is, or the future, more powerful technologies would be great. I'm really interested in how exactly a computer works, even on the smallest scale. So, a video about that would be nice, but its probably too complicated for such a large audience. Anyway, you guys are great. Keep going.

Teaching us about something they don't really know, classic LTT.

Linus uses xbox 360 power adapters as murder weapons. Edit. Wow 7 months later I forgot about this comment and didnt expect this many likes. Thanks. :]

Linus forgot about GaN chargers like the anker Power port from ces which are much more smaller

I've used a couple of those old xbox 360 power adapters as 12VDC power supplies for surveillance equipment installs, those things are amazing.

4:12 Incoming review of the Huawei P30

Yea but was that Xbox 360 huge industrial style power connector not kinda badass

Just learned about this in science class

nice detail with the 50 or 60Hz when showing the wall socket :P

One word- safety. In the UK, a mains socket can be dumping 5 x 32 x240 Watts into a faulty wallwart before the breaker trips a fraction of a second later. That's about 40kW. Think large fireball. Don't buy cheap wallwarts, period - you really, really don't want that to happen. Ones on a lead with a mains plug are far safer (in the UK) - there's a fuse in the plug that can limit that power dump to 5x3x240 Watts. Think quite small fireball. If you really must use no name wallwarts - plug them into an extension lead with a plug fitted with a 3A fuse. Size, as they say, does matter. But quality matters more.

And DO NOT buy cheep Chinese power adaptors / phone chargers from ebay. Often made to very poor safety standards, and the mains reference voltage can leak across to the low voltage side. Several teenagers killed in the last few yrs charging their phone while in the bath !. 1. You should never do that. But had it been a genuine apple adaptor etc that would not have happened.

0:49 "The basic reason for this clunky boxes is that our modern electronics can not use the raw AC power that comes directly drom the wall. Instead it has to be converted to direct current or DC." While he says that a full-bridge rectifier is shown over the power brick. Of course, AC-DC-conversion has to be done, but that is not the reason why the power bricks are so big. Yes, later you also talk about the voltage conversion, which is really the reason for the size and weight, but that doesn't make that sentence at the begining less false. I just hope ElectroBOOM won't see this.

1:00 There's A Bridge Wave Rectifier! Nice!

Standardization helps by letting you carry fewer proprietary power supplies. This has improved a lot in recent years. I pay a few $ extra for camera battery chargers than can run from a USB charging brick.

He missed the main point. AC wall electricity is dangerous because its ac and its high voltage. Phones are very abused, they get dropped and dropped in water(sometimes even salty water which is conductive). A failure in the power adapter can result in a overvolt of different components in the phone's/laptop board and damage to them. It might also exposed or short the live wires which is the most frightening to me

**Screams of earliness** RYZE N' SHYNE NOTIF SQUAD (Get it? Ryze 'n? That was in a LTT intro...)

Good vid, very informative and comprehensive.

The sweat drop from his face at 2:10 XD

You know what else is HUGE? 1:40 This guy's bruise on his face

There is a good AC/DC video by ElectroBoom

When he said AC DC. I was like........ I’m on a high way to hell!

Honestly, the scepter x360's power brick is pretty tiny, basically a quick charge phone adapter with a cord on it. Pretty neat.

i love how he says "gaming laptop" seriously

Between the shrinking size of higher power adapters and the shrinking size of motherboards in laptops as more stuff gets integrated into fewer chips, many modern laptops have plenty of internal space to spare for an internal AC-DC supply. I suspect their main reason to still use external bricks is simply to delegate the liabilities and safety certifications for AC-powered equipment to a third-party supplier.

FULL BRIDGE RECTIFIER

I would appreciate if you could find a commercial about support for hearing aids as it would be helpful for me and other who has hearing aids of all kind.

Linus tryna learn us 'bout our AC/DC..psh who do you think we are, Canada?

The xbox360 Jasper isn't the original 360

Linus, are you aware of a major reason why manufacturers use external power adapters? There is a loophole in allowable RF emissions regulations: Manufacturers only have to submit one model of a power supply for certification. They will build a power supply with quality components, get that "version" certified, then start cutting corners on internal components until the power supply greatly exceeds RF radiation limits. (With a cable toner, you can hear these "dirty" power adapters for laptops and electronics from across a room!) These RF emissions/dirty adapters are bad for connected devices, interfere with other devices, often exceed federally recommended RF radiation exposure limits which is bad for humans, they don't last as long, and they are less efficient. By building the power supplies outside of devices, they can more easily cheap out in this way.

I died with the "wall warts"

Hello

Can you do a video on why AC and/or DC will Shake you all night long?

1:39 "Wong, you're invited to my wedding!"

I like how he is talking about undesirable bulk while showing the most undesirable bulky laptop

220V? Is it 90's?! Almost all EU countries are on 230V.

You didn't explain anything.

1:07 linus: you can learn more aboout AC and DC me: BACK IN BLACK!

What about Gallium Nitride base power supplies

AC/DC Thunderstruck!

Did you just explain AC/DC without explaining the acronyms ... Alternating Current & Direct Current ?

4:50 so apparently everybody bags their bags like they're gonna shi* two times a day everyday on the vacation/trip

Nice vid thanks here is suggestions make video on "what happened to tungsten filament bulbs"

switching refers to the use of pwm modulation to provide current to load, this video is innacurate

Wow 1 minute! Im early. 360p Club!

I was hoping you would discuss the new GaN technology for chargers on this video. Anyway, maybe on the next videos.

What happened to the previous tech tips episode???