That's important for switching power supplies, especially small ones. A switching power supply is always a few milliseconds from being a short circuit across the input. And FETs fail in the ON state. That's why those things are inherently fire risks and need protection circuitry. Really tiny ones make it worse; if they fail, there's not much space to dissipate heat before something blows and opens the circuit.
If the thing works as advertised and is safe, it's amazingly useful. It should quickly charge absolutely every device I have except my work 2015 MacBook Pro (that I'll likely replace soon), and up to for of them at once. (Eg laptop, phone, battery pack, and wireless headphones simultaneously.) Handle US or EU input. And be very compact.
One time it happened in Australia, who investigated the cause thoroughly:
> We know absolutely that the charger itself failed, and that it arced between the 240 volt input and the five volt output. So that's definitive," said Lynelle Collins of NSW Fair Trading. "We've got photos, we've got proof that's been dismantled, so we know that the charger failed.
I'm on the fence about keeping this thing. Besides the safety question, it's a little disappointing that charging a USB-C phone will drop a USB-C laptop's power straight from 100W to 50W. That's quite a step; I wish it could do something like 85W + 15W. When you use all four ports, the laptop only gets 38W, even if the others actually take almost no power. I think their claimed "intelligent power allocation" is overselling it a bit.
Looks like one of the reviews on Anker's product page (titled "Versatile, depending on what you plug in") says exactly what combinations are possible:
There have been a lot of improvements in this space in the past 11 months.
I bought the RavPower 61W, the 40W one, and some non-GaN USB C PD chargers.
They all seem really good.
the question is what you're basing this assumption on. Fake Apple chargers also "seem really good" until they blow up or are disassembled to unveil the obvious electrical issues.
I travel a lot, often with more than one laptop, so now I'm very happy I can charge all my electronics with this one charger and also with the changeable country tips it's more compact than a travel adaptor.
The only downside I've had with it is the US power tip got bent the first time I used it - I contacted Innergie to see if I could get a replacement, but they never got back to me.
It's quite quite common for people to manage to bend the prongs on their vacuum cleaner dozens of times. Those pull more amps than almost anything else you plug in regularly, and they do just fine. Just go slow.
Works fine if there is no earth pin.
I mean, since this thread doesn't seem too picky about fire safety anyways... ;)
I'm hoping that giant power bricks and those adapters that power via barrel plugs will disappear soon, as I find them to be unwieldy and dirt magnets. Computer monitors are most guilty of having some of the biggest power bricks, and I'd love to see them replaced with regular power cables (the ones that plug into desktop computers), or the monitor be powered over usb-c so any regular 100W usb-c adapter can power them.
Dell Monitors have a single power cable (for example this P2418D ). Many other manufacturers ship giant power bricks because it allows them to make the screen thinner, and nobody sees the power brick under the table. It comes down to customer preference.
Laptop makers will never let that happen. My partner and I have had 4 USB-C laptops between us for work from Dell and Lenovo and the Dell 90w USB-C Dock PSU is the only one that could power all 4 of them. Each one complained or refused to boot if a different charger was used. The wattages for all of their supplied chargers were different.
The charger body has two fixed pins inside a circular collar with two tabs on it that the tip is placed over then rotated 45 degrees to lock.
But I'd want a long (10 feet) USB cable for those places where the outlet isn't near where I sit, and it doesn't look like that exists yet. All the ones I find on Amazon are 3A, and the MacBook Pro apparently needs 4.3A.
Anyone know of one?
Haven't used it for 100W charging so I don't know if it stands up to the full rated 5A though.
[*] https://idaffodil.co.uk/products/slim-foldable-usb-charger-a... to pick one at random from a quick search, or https://www.amazon.co.uk/dp/B07VDJLD1Q/ for C-type though that is only 15W not 45W like the Mu C-type models.
There's a pretty good site, https://www.chargerlab.com/ (see also: https://twitter.com/chargerlab ) that's dedicated to reviewing charging peripherals.
I started off the year with an Innergie 60C, which has worked great for everything I've thrown at it and is tiny (55mL volume, 88g, 60W USB-C PD). It was on-sale recently, but even at full price has been worth it for me. (Although the newer RavPower PD Pioneer 61W is a good alternative that's almost as small and 1/3 the price.)
I'm looking forward to adding the upcoming Sanho HyperJuice 100W charger (about twice the size, but a bunch more ports) https://www.kickstarter.com/projects/hypershop/hyperjuice-wo...
Instead of the Anker PD1 18W, for a small charger, I use the Anker PIQ 30W - it's very slim, which actually makes it much easier to carry around. Also, the IMO folding plugs (and extra juice) are definitely worth the extra volume.
Recently, for my Mavic Pro 2, I just got a cheap Cablcc USB-C to Plug Receptacle Charger cable and a RCGEEK car charger that seems to work well as a nice 2-in-1 (it only saves a tiny bit of volume and weight over the wall charging but it also provides car charging).
Also, although I'm unsure of how often I'll need it, I got a 100Wh Zendure Super Tank power bank (which provides USB-C PD 100W charging), since it was discounted heavily for Black Friday (it was only $100 on sale vs $200+ for other similar options).
Also, I travel internationally a lot, and the MOGICS Donut has been my go-to combination power strip and adapter - it's the best/most compact device I've found (and has 2 USB-A chargers built in to handly legacy devices). https://www.mogics.com/3824-2
One thing to watch for with decices that use the same port for in and out though:
1. Portable charger runs out of juice before completely charging running laptop.
2. Shortly thereafter laptop notices an empty battery connected.
3. Laptop dutifully starts sending power the other way to recharge the battery...
I purchased the Innergie after a previous travel charger failed. Loved it at first, but started experiencing issues pretty quickly. The first issue I encountered was that the plug would fold in frequently while I was trying to plug into outlet. Over the course of a couple months, I started seeing more issues with the reliability of the charger as well. It never completely failed, but I would often have to play around with reversing the cable and the direction of the outlet side usb-c in order to get charging to start. This was a bit concerning to me given that complaint USB-C cables are completely bi-directional.
Additionally, is there a good charger with EU plug that I can use to charge both my MacBook Air 2018 (USB-C) and my iPhone X with at the same time?
As it happens, I have the Atom. Yes, it's true that it can barely keep up with my MBP while in use, but that's not how I use it. It's fantastic as a more convenient option overnight, or as a second charger for my phone, my Switch, etc. I already have a bigger four-port, and any single-port can only be an adjunct to that, so a single-port that can do 60W adds no value. I suspect people in situations similar to mine far outnumber those for whom a single 60W port would suffice.
GaN mosfet costs 10x more  than a silicon one of similar power rating. And the multiples gets wider at 15x for 1K units.
I doubt we will see Apple include a GaN charger as default for quite some time.
: IPAW60R380CEXKSA1 (silicon) costs $1.26, IGT60R190D1SATMA1 (GaN) costs $13.
And the link to my previous question's answer  from an electrical engineer. I will paste it here as well.
Cost, and the fact that it doesn't actually buy you much. I've evaluated GaN for a couple recent designs I've been involved in and found that its benefits simply didn't justify its costs.
What GaN actually does is, mainly, decrease switching losses. That means switching frequency can go up, or efficiency, or power density. These are all good things, to be sure, but the magnitude of improvement GaN brings to most designs is simply not large enough to justify the cost of the parts and the increased design attention needed to use them. (They're fussy little things.)
That said, I'm bullish on GaN in the medium-term. There are some cool tricks that are infeasible or impossible without them, and they really are better in a lot of ways. It'll just take a while for them to trickle downmarket, and even still they're not going to be replacing Si FETs anytime soon. (Part of the lag in GaN adoption is simply that Si FETs have gotten really, really good.)
Yes, size is the main product-level advantage of GaN. But it only lets some of the system shrink; for something like a mains charger, you still need the isolation magnetics, so your overall size is still constrained. And at the power levels of a few watts that many chargers work with, Si FETs are simply good enough. A 5W USB charger isn't going to get any smaller with GaN. It only starts to get interesting with really high power densities.
I have a Kill-A-Watt for rough measurements and the pi4 charger is slower than my GPD Pocket or ipad pro charger. It does pull 14W or so sometimes, but there's a big limiting factor, it's only 5V. The ipad charger does 5V/9V on USB-PD and the pocket does 5V/9V/12V. So if the cable wears at all, you won't be getting the full rated power due to voltage drop. It's like trying to use a plastic mixer straw to drink a beverage vs a regular one.
I already have a portapow meter for measuring USB-A stuff including watching quickcharge 2.0 stuff boost the voltage on the line. Proper USB-C meter/tester comes this week, then I intend to writeup findings on cables/chargers.
But when you to bed, your phone doesn't know that rapid charging convenience doesn't matter. So it will still make the same trade-off. If you use a less-powerful charger, you can force it to take its time in charging.
iPhones now know that you're going to bed and adjusts the charging to match https://support.apple.com/en-us/HT210512
I believe some Android phones have had the same feature for years now, dunno about the base android OS
In particular, the 60W USB-C + 3x12W USB-A brick is really nice.
If you don't want to see the LED you can cover it with electrical tape.
I’m glad to see it’s finally reaching a useful commercial application.
What’s interesting is how the DOD heavily invested in GaN technology in 90s and 00s, pushing the USA ahead of Japan in compound semiconductor. Weather that lead will stay; who knows. The Chinese have a GaN fab now. GaN is critical for RADAR and higher power SATCOM, so big defense support that has dual use for civilian wireless comms.
Wait wait wait... GaN and SiC have very, very different use profiles, and characteristics. SiC is by no means obsolete, and nor are purpose made silicon switches.
SiC is here to stay because of one very unique trait among all other semiconductors - a very pronounced negative temperature coefficient, and without extreme non-linearity.
Second to that is more or less linear threshold voltage temperature coefficient. GaN has positive threshold voltage temperature coefficient.
Third, SiC can simply operate at higher temperatures, and have known longer lifespan. GaN's current limits are WAY lower.
Fourth, transfer characteristic... Si, GaN, and SiC are all very different. This is one of few measures on which plain silicon beats contenders.
How does the negative temp coefficient help; stability for very high temps? I know the positive temp coefficient was an issue in RF BJT, requiring ballast resistors for stabilization, but those are not needed in any FETs. The positive temp coefficient should be useful for GaN as long as you have temp stabilization in the bias network; all of my amps did.
Good point about the high temp. I know of some oil drill electronics in SiC. I just though SiC was dead for RF.
You can put multiple switches in parallel, and have them self balance without resorting to active temperature compensation which is completely out of question for any consumer grade device.
For power electronics, GaN is nowhere near as big of a bang as SiC, with its current handling being the primary showstopper. SiC can switch 100A loads at one kilovolt and above with ease, and at very high frequencies. There are simply no equivalent GaN part for this comparison.
Second to that, GaN needs a tricky gate driver, and is normally an
n-channel depletion mode device. SiC can still be driven driverless at lo
Second to that, SiC JFETs still have niche uses in audio amps exactly because of their "bad" shallow IV curve.
The FCC needs to enforce emissions regulations. I remember when PCs (even the C64) had cases to meet emissions requirements. Now you see PCs in glass cases. It really sucks doing amateur radio in an urban area due to spectrum pollution.
The country I live in happens to use the type F connector, which is very sturdy.
Incorrectly wired outlets do occur even in the US, so it seems like it's safer to take that possibility into account and just design the whole system to allow them to be interchanged (e.g. make power switches open/close both lines)
On appliances with a physical on-off switch, it's best to have the switch as close as possible to the cable, and on the 'hot' side. If there's a fault (wire touching the metal case) then the appliance is still safe with the switch 'off'.
Nowadays, I think everything would have double-pole switches anyway.
The american design is clearly superior.
Perhaps it isn't common, but my experience with the sockets in Belgium was scary to me because there were two outlets embedded in a recess quite close to each other. Close enough I was afraid I'd shock myself trying to get a good grip on my plug and pull it out.
Perhaps there's a hidden mechanism that enables power after insertion? There was no switch for each outlet. I no longer remember if there was a switch for the pair of them but I don't think so as I was worried about getting shocked. This was in a Belgian hotel I visited a few years ago. Sorry I didn't take a picture.
This is probably the only case when CEE-style socket is not designed such that it is safe to use with any CEE-style plug that mechanically fits. In general I view the system as better design than BS 1363, because it solves the relevant safety issuess without overengineering and with reasonable degree of backward compatibility.
Outlets next to each other, still without cover: https://www.entscheider.com/elektriker-und-elektroniker/wp-c...
Maybe even like this (seems to be older): https://de.wikipedia.org/wiki/Schuko#/media/Datei:Doppelstec...
Definitely not normal what you describe there. I'm glad you were cautious.
From my experience with some amount of traveling, I would agree that its very nice to use in practice and definitely got a lot of things right.
Modern US receptacles are “tamper resistant” and are required by code in places that kids can get to, and they have similar safety shutters. Unfortunately, many of them, especially the cheaper ones, suck and actively eject plugs.
The lack of insulation on US plugs to prevent shock when plugging and unplugging is a fair criticism. I suspect this is mostly because US prongs are thin and could become too weak if the metal were narrowed to make room for insulation.
Anyone who thinks the English are a reserved polite people has never seen one step on the surprise plug.
European travellers are generally impressed when I show them this trick, and sometimes rightly concerned that I'm sticking metal objects into a power outlet. If there's any chance the outlet is wired incorrectly, don't do this unless you can isolate the outlet or the key.
(Source: frequent socket replacements at a British university.)
It's also a fascinating example of standards proliferation (https://xkcd.com/927/).
European plugs IMO have the right balance between safety and size, with the bonus that they don’t stab your feet if you step on them.
A feature mentioned even in an article praising them as the best in the world (https://www.fastcompany.com/3032807/why-england-has-the-best...), linked elsewhere by dpeck (https://news.ycombinator.com/item?id=21678124):
> It’s a truly brilliant design. The only caveat is that, as with Lego, the rugged, bottom-heavy design of a U.K. plug makes it an almost scientifically perfect caltrop.
True but I have to say the combination of UK plug adapter mated with a US power strip is extremely convenient. Particularly since modern UK outlets all have individual switches which comes in handy when you don't want a snap and a spark plugging something into the power strip. :-)
Also, more expensive to manufacture?
It's fantastic for travel. It can charge my laptop (USB-C), Apple Watch + iPhone (USB-A) and power bank (USB-C) all at the same time. It also has a detachable AC cable so you can swap it before you leave instead of carrying an international plug adapter.
For power supplies and switched mode RF amplifiers, you need to switch the transistor on and off as fast as possible; ideally an open or short circuit. During the time is is transitioning from on to off, it is dissipating power, thus losing efficiency in your circuit.
If you can operate at a higher bias, your passive support circuitry can operate at a lower current (lower I^2*R losses) not to mention smaller due to higher frequency (smaller inductors and capacitors).
The faster switching also generates more harmonics, which can align in phase to cause higher voltage transients, thus you need a higher breakdown.
The issue with GaN is fabricating it. It is a compound semiconductor grown with epitaxy (layer by layer) and has to be lattice matched to a carrier substrate, unlike Si which is diffusion doped into the bulk Si substrate. So GaN is maybe at 8” wafers while Si is much bigger. Some GaN is on Si carrier (cheaper but lower thermal conductivity) and some in SiC (expensive but better thermal conductivity). The goal is to grow it on diamond, but again the lattice matching is a problem.
The longer term goal is diamond semiconductors. Maybe 30 years from now that will replace GaN, as GaN is doing to GaAs and Si for certain applications.
It doesn't really explain anything.
We can't make GaN transistors nearly as small as we can make silicon ones, but transformers/chargers don't need many transistors in them, so it's fine.
First, I will say that GaN is not a make or break deal yet now. There are very high performance silicon switches that can produce equal gains for use cases in consumer electronic. In absolute comparison GaN is of course winning over Si, but use case wise, not so much.
GaN's main appeal is that you can retrofit it into simplest buck topologies, and get instant gains without any extra hassle.
GaN works best for low current, low voltage applications you normally see in consumer electronics. Everywhere else besides RF, it's not a clear improvement over silicon.
For long time GaN existed in a narrow niche of high frequency circuits, where people were OK with n channel depletion mode device with a lot of tricky sides. Its use as a power switch is relatively novel.
Enhancement mode devices are now on the market, but there is a catch. Because p-GaN is nowhere near as good as n-GaN, pure GaN enhancement mode devices are nowhere near as good as depletion mode devices. For this reason, some companies are trying a an approach with hybridised GaN-Si device to overcome that. Again, that is way more tricky and expensive than a single material device.
Now, back to chargers. It is easily possible to make more compact chargers without any exotic switches GaNfets included for as long as you put just a little bit more brains to engineering by going to better topologies.
What a lot of charger makers do these days to go along with the trend for smaller chargers is to turn up their switching frequencies as much as possible without melting the charger. They still do miscalculations about that, and you now have a lot of molten/burnt chargers as a result.
They are being misguided by the switching speed narrative, and completely miss that point that size of passive components has to do with way more things than just switching speed.
First, they can throw away the standalone rectification, gaining some efficiency in the process. Second, they should either go with some advanced flat transformer setup with appropriate resonant topology. Or they can throw away transformer altogether and use piezo transformer, or capacitive isolation. Third, a separate buck for last stage DC-DC can also be thrown away if you use multitap transformer and some electronic switching.
Transformers are by far biggest contributors to charger volume, and weight, and are bigger than capacitors in some cases. Throwing them away will provide way more space savings, along with other extraneous components.
So think twice about going the GaN route before considering things above first. Switching performance in a typical AC-DC is by far not the biggest of your problems.
I saw the GaN stuff on US Amazon but cost and specs seemed worse than the uk ones.
eg the uk Anker 60W ones cost less look about the same size can do 30W PD and has another 5 ports too
I just don’t see the value proposition of these GaN ones
Umm wot, maybe older MacBooks, maybe when gaming or rendering. For writing code and browsing on a 15incher I'm averaging 20watts. Cheap 12v cigarette lighter one that does 24w is enough (but barely) to keep things running for me. If I turn off most of apps I get as low 6watts on a hexacore device. I use iStat menus to monitor my power use which is quite exciting.
Although you can use an under-specced adapter it probably won’t be enough to power and charge the system while fully using the CPU, GPU, and screen.
I am actually considering buying 30W one for it's portability.
But then again I am not a YouTube influencer that occasionally games and cuts videos (you know, the person that Apple designs it's computers nowadays for).
I develop software in Apple's programming language using Apple's frameworks and Apple's own IDE, and power usage is through the roof. 50W while typing (and auto-complete is doing it's job) and 80W while building.
I think it's odd and quite rude that you dismiss anyone who has higher computing than just typing some basic text and browsing the web to be "a YouTube influencer". If all you need is the computing power of an Eee PC then yeah, I don't think you are Apple's target market.
My Pixel 4 charges at 18W, and I'm probably good as is.
Power is measured in watts.
Current is measured in amps.
Potential difference / voltage is measured in volts.
The wattage capability and size of these chargers is only possible because of US “power delivery”. These chargers are NOT hitting 30+ watts at 5V traditional USB voltage. Yes, there is another power and ground wire pair in the cable, but iirc they got smaller in diameter.
These devices are small and cool there because your device can charge at up to 20V now.
GAN didn’t outright make that happen on the source or sink side. It didn’t hurt, it’s cool, but the difference is smaller than they are implying by comparing a 5V device to a 20V device.
An article that goes on about fast charging and never says “20V” once is not telling you the full story.
They’re not making the new models bigger just for fun.
Lock it down to 5V and the size goes way up. The comparison to Apple’s 5V and 5W from like 2008 is at best misleading.
Are these smaller because of better silicon, yes, are they marginally smaller and the real difference is USB pd, also yes.
I understand the logistics issues involved in standardization of repeatably used sockets but USB chargers are so very "unhygenic" from a security perspective. Proper design from the data end shouldn't allow any unexpected changes but that is error prone in practice. It is sort of like sharing cups - in theory the immune system should take care of any pathogens but in practice it is a needless risk.
Getting into engineer dreams, an ideal design would involve readily apparent subsets between charge and data pins even if they occupy the same socket. So any charger honeypots to plant or extract data would be obviously untrustworthy.
It's pretty mild unless it contacts something made of aluminum. Then it's fairly impressively destructive.
Surely not more toxic than gallium arsenide. The amounts of material involved in a manufactured product are pretty tiny, so the semiconductor material is not hugely concerning.
It's gallium nitride.