Masterplug USB Socket Teardown
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- Опубликовано: 5 апр 2019
- What's inside a Masterplug double socket outlet with two USB charge ports.
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The transistor is made by Alpha & Omega semiconductor. I can't be bothered to look up the exact part, but it's 100% going to be an N channel MOSFET.
The tab has not been chopped off. It's a DPAK style package that looks like that. Normally it would lay flat on the board and be soldered to the board for thermal dissipation to a heatsink on the same or opposite side of the board, thermally connected to the copper. However, it's likely running far below its maximum rated current, so thermally, it's probably fine.
The likely failure mechanism if it continually turns on and off, is the bootstrap capacitor, which could be the ceramic C6 on the bottom of the board. I would send it to a bearded bear for further analysis though.
The failure could also be due to the diode on the feedback winding having failed, or indeed the feedback winding on the transformer.
I assume the bearded bear is Big Clive, I am a great fan of his channel. Cheers from Canada.
I don't like the idea of consumables being put into the wall. The outlets should be considered permanent fixtures that require zero maintenance and have near zero failure rates.
And eventually they'll become obsolete. Many modern phones want USB-C at up to 20V 5A
No big deal though. You can still plug in a normal charger block, just sometimes you don't have to.
I totally agree with you.
@@dom1310df They should supply a transformer plug. Outlets can last upto 50 years and if the average house hold has a dozen outlets who wants a dozen outlets using electricity especially if they are not working but still drawing current? Bad enough having mains power with the problems that generates such as loose connectors and arcing without usb outlets, they should be pluggable.
Also they always consume power, sure not much, but multiply that for N sockets in your home and you have a couple of W of consumption just for doing nothing. Also being always powered means that the switching PSU circuit will fail sooner. They could at least put a switch to disconnect the USB part of the socket so you only turn it on when needed.
That fellow's handwriting is top notch!
It's a font.
@@benmjt - Really? Any idea of the name of the font?
@@Pithead Lucida Handwriting
@@Gameboygenius - Ah, thank you!
“For people who don’t like looking at screws” made me laugh out loud
Very interesting to see how they work from the inside. Thanks for that. I agree that they need to have a method of turning them off. I usually put a fused spur with them when I install them.
I like the UK plug and socket outlets, far superior to North America, but I do not like the idea of USB chargers built into wall plates.
comm744 especially if there isn’t an earth attached to the other case of the usb
American practice is better though, imo. The accessories are poorer quality, but the huge working space in the backboxes and breaker panels, was a revelation to me (i did maintenance at a motel for 5 yrs there)
@@TheChipmunk2008 You need that space though, because the cables are so much thicker to handle the lower allowed voltage drops. Then you are passing 30A through the thinnest smallest steel spring stab in contact, what could go wrong with having a mini toaster in every connection.
Here at least cage clamps and screw terminals for connections are the only thing, push in connections are only for wire connections, where you can also use crimp connectors or ceramic wire nuts, which do not melt.
They make receptacles with USB ports for North America as well.
@@SeanBZA True if you use the backstab connections. I never did. But no socket circuit with normal outlets is 30A in the US or Canada, 20 is the largest breaker for general purpose circuits. It's why so many youtube makers in North America keep going on about 'can't run x and y together or it trips a breaker'. Seems a bit precarious to me lol
I'm surprised more of them don't just add a couple of new breakers for the workshop?
Send it to Big Clive. He enjoys trouble shooting switch mode power supplies!
and then blowing them up 😁
I was just thinking the same!
Culprit is probably one or more electrolytic capacitor whose internal esr has rised due to ageing. When this occurs, power supplies are working until one load them, then output voltage drops, which resets charge. Then everything cycles again and again. Usually, if those capacitors are replaced when facing such failure, the device runs again fine for certain time. The too quick ageing of those capacitors could be due to several reasons or a combination : too high ac current component, too high temperature, too high voltage or poor capacitor quality.
My little experience on switched more power supplies...
@@gilwyckmans yep, usually dried up 'bootstrap' cap , in some circuits that cap or a similar one is also used for feedback voltage control, a duff cap can cause the output voltage to rocket , as sometimes could a resistor going high, had this trouble a lot in crt tvs in the '90s, can cause a chain reaction blow up
@@andygozzo72 Definitely so. I also enjoy the videos from a fellow Canadian engineer from British Columbia, Electroboom. He is a real blast and definitely gives himself a real blast quite regularly. But he is very knowledgeable. Shocking to say the least. Also I have had my share of fixing crappy blown class Y capacitors. Seems to be quite a common problem. Cheers from Canada.
Hopefully standards will be updated to ban these things, or at least make the power supply switch off when not in use as you said. Interesting to see it.
Totally agree, it will take a dozen house fires caused by this junk for the rules to change.
Interesting, very impressive macro photography.
Thanks for sharing and best regards from the Black Country.
is it still drawing some standby current from the mains despite not doing anything useful?
Guess a lot of these will just be left installed after the charger part fails providing they're not emitting smoke and fire or making any annoying noises.
Hopefully the fuse is not cost cutted out, and this even when working is probably using 2VA all the time, so costs you money all the time.
A good idea to make chip marking clearer, is to smear on eraser fluid (you know the white fluid you use to paint over miswritten ink) and then wipe off with some paper. The fluid will remain in the laser engraved letters and will make it much clearer. (dont push too hard with the paper when wiping, just so you wipe off Everything around, you might have to experiment around a bit Before you "get it right")
Cheap white thermal paste also works great!
7:41 the material on the back is heat sink pad material. If you've ever removed a cpu cooler you'll see that Intel (or laptop/pc manufacturers) use exactly that material between a CPU and heatsink.
For CPUs it's enough to stop them overheating, but removing it, cleaning the surfaces, and applying CPU paste lowers CPU temperatures 5-10 degrees.
Not sure if anyone else has answered what the FRYK is, but it appears to be an ACT413 an Active-Semi ActivePSRTM Quasi-Resonant PWM Controller
The problem is it's a piece of electronics attached to a permanent electrical installation. I'm still not convinced by active RCDs, let alone anything more complex
Yeah seems like an unholy hybrid of things that belong in entirely separate categories... I'd be a bit creeped out having cheapo consumer electronics I can't switch off inside my sockets. You can buy reasonable external usb chargers and wi-fi boosters for less than these all in one units - which just seems like the best way to go IMO
Makes sense to the socket manufacturer though, they get to sell a £12 unit instead of a £2 unit... if the consumer replaces it with another USB socket they've got a nice repeat sale going - better than selling normal sockets that basically last forever.
@@joinedupjon my words exactly!
I think there is a common consensus that these unholy hybrid unswitched abortions are not a very good design. How in the heck did they ever pass certification with UL, CSA and other standards boards is beyond me. As another Canadian AvE puts it, chinesium crap.
Also there are some multi power outlets that include USB ports and they are permanently on, even when you turn off the switch, that only cuts power to the sockets. The USB's in this case should have a sleep mode + button like some powerbanks when no load is attached to reduce power drain and increase lifespan.
Can I ask, do usb sockets make very low humming or buzzing when not in use? Mines seem to do so but can only hear when my ear is literally against it 😂
Give it a jolt on the mega ,see it there's any magic smoke left in it. Great bit of macro work there
I Just got an Anker 5 port USB charger where each port is supposed to give out 2.4 amps each. So, about 48w (approx)
The IC marked 'FRYK' is an ACT413 PWM controller
John you always do great videos with easy to understand explanations. Any chance you can review a socket with both USB a & c? Or do you at least know which is a good brand for one because I’ve seen a few on places like screwfix where people have said the usb c port has failed in a short period of time
Could you compare the quality to some cheaper versions of USB sockets to the higher end MK version? Would be interesting to see the differences, if any.
When JW extracted the charging board and began the visual inspection , you could faintly hear Bigclive’s immortal words: ‘I’m not seeing any skid marks.....’
couldnt they have some sort of switch in the mains feed to the usb power unit, triggered by a usb plug being inserted?
John, can you forward this to BigClive if I pay the postage?
One of the better ones I have seen. Probably the main switching transistor or an output cap failed. You should see some of the cheap 5v usb power adapters on eBay and Amazon if you want a horror show. No fuses, Risible isolstion between primary and secondary sides, transformer windings isloated only by varnish, no snubber network, non-safety capacitors across transformer. Keep it up.
oh, yes, i have one with no fuse at all in it...relies on thin wires between the plug pins and its pcb !! and then theres the definitely not high enough voltage not class y2 compliant capacitor between live mains and the usb output 😲
Those sockets are designed to go in 25mm back box so everything is shrunk down to make it compact. Look at the USB sockets from the premium brands like Hager or MK and they are chunkier and require a 35mm back box to be fitted.
I bought two LAP usb c sockets from screwfix. Fresh out the box, they are installed but the usb c sockets dont work. What could be the issue?
I've always thought that these off great convenience, but would never install one that didn't have a third switch to cut the supply to the charging circuit. Does anyone at all make one of these where it is possible to turn off the charger when not in use?
One of these burnout recently as it was overloaded. I had presumed that the 2.1A would be proportionally divided between both USB devices plugged in and did not realise that user input was needed. Is it true a USB devices max input should be checked first before plugging it in?
USB sockets should contain overload protection, and not output current that would cause overheating or damage regardless of what is plugged in.
The socket should either reduce the voltage to reduce the current, or disconnect completely if the load is too high.
I think this is BG plug socket made for Wickes - looks exactly the same
Masterplug is a BG brand.
If you're going to have one of these running 24/7 over many years, you should at least use components that are up to the job. Generic Chinese capacitors are never going to last all that long in a high-stress circuit like a switching power supply, and Chang are the lowest rung of all (I doubt 'GD' will be any better even if they're "low ESR" versions). An extra 20p on reputable Japanese passives and these things might at least last 5-10 years.
Use solid aluminum polymer capacitors or MLCCs and the thing might last 30 years. Like so many things these days, it's built down to a price!
That is the point. Companies do not want things to last anymore as they get more money with repeat sales.
Biggest thing to do to those is simply make input protection better, add the inrush limiting resistor ( not there, unless it is in the input wires), some common mode filtering, some overvoltage protection VDR across input, and a power switch. Once that is done you can put better capacitors in there, and it will last 30 years in service like the old socket was designed for. Only issue is that more than doubles the size of the board, and you cannot fit it in the volume available without either increasing external volume outside the wall box, or losing the one outlet for this volume.
But the modern socket is hard pressed to do more than 5 years, especially if you actually expect to draw anything like more than half the rated current, and use the switch every day, and do a plug insert cycle every day. Sockets used for things like vacuum cleaners, or in kitchens for appliances like toasters and kettles that are packed away after use rarely make it to more than 3 years. Switches are too flimsy, plastic parts break or disintegrate, the thin brass contacts overheat and lose tension, and the whole thing just plain wears out. Old 20 year plus ones still works, but the new ones next to them fail.
hmm, dunno how bad chang ones are, have had some supplied to me as supposedly 'good' replacements,
@@andygozzo72 The original Chang capacitors were made by Huawei and were reasonable, but they have been copied by all the crap cap merchants and are now 99% certain to be poor. If they have a bullseye bung on the base they're cheap.
Surprised that a built in USB voltage i tested (UK) was giving out less than a standard IPhone plug !
Great job.. keep up
I would have put an ESR meter on the capacitors and worked out which one(s) had failed. They look OK but it's likely that one has gone high ESR and low value.
Post it on to Big Clive for a full root cause analysis. We don't even know if you confirmed the fault is real, or is due to some problem with the user's device compatibility with this thing. That said, it is asking for trouble having a cheap SMPS sitting permanently on, I do agree...
I just bought a chrome LAP one of these. Wish I hadn't bothered now. I think I'll take it back. Didn't know they were on all the time. It's not just the cost, it's things like heat build up inside the wall that I worry about, and failing electronics, capacitors burning up etc. This kind of thing will keep me awake at night. Just how safe is this technology?
Isn’t it exactly the same as just plugging in a regular USB adapter, accept it’s just inside the socket?
@@Lift.Tracker Regular USB adapters have a fuse at least, or should have. They are also outside the socket so not prone to heat buildup
@@ArcanePath360 I see what you mean. I’m not really a fan of these either. It would be interesting though if John compared cheaper models such as this one to the more premium MK ones. I wonder if there’s any extra safety / reliability design features.
R4 or R5 are high in value, so that is the start up circuit not allowing the circuit to start up and cycling, or the diode D1 associated with them or R3 is open circuit, so the chip cannot get it's operational power properly. Otherwise C5 has cracked and lost capacitance. Capacitor wise the output and input capacitors are not the worst, but in reality this is not a 2A power supply, really a 1A one that can supply 2A for up to a minute once an hour. the pad at the bottom of the board is a silpad thermal transfer pad, there to move the heat from the power diode on the secondary and the primary side switch transistor ( and the RC snubber across it) to a larger surface area of the plastic case, so there are no hot spots on the board.
Would be better with an actual third switch to turn it off when not in use, and even better with it only being a single socket outlet and making the power supply the second side, but limited with the room allowed in a double gang outlet means a lot of compromises there. Seen those type here, and would never install one for myself. Did however see the local version of the universal deathdaptor, and was tempted to buy one, as this one actually has a BS1362 13A fuse in it, unlike the UK versions. Almost bought a shaver adaptor, as it was selling for under 3 pounds, and actually has safety approval, non resettable thermal fuse, and 16VA rating isolation transformer with 110 and 220VAC taps in it, and fits in a single gang 4x2 deep socket, though you are going to have fun if your plaster and tile depth is not 20mm or more getting cable in.
Top notch analysis. These are the reasons why I enjoy reviewing comments on good channels, there is always so much to learn and discuss with like minded chaps from around the world.
We have these type of things in an office at work, they emit a fairly quiet but high pitched noise all the time, even when not in use..
I’d never fit these at home.
it's an issue with quite a few switch mode power supplies, when operating normally the switching is ultrasonic so you don't hear it, but under no load the switching frequency drops significantly and can become audible.
Can I ask, do usb sockets make very low humming or buzzing when not in use? Mines seem to do so but can only hear when my ear is literally against it 😂
I would never consider installing any of these types of socket outlet, as
1 - I don't like the idea of having permanently powered up electronics buried in the wall.
2 - They're using a small amount of power all the time, especially if you have several sockets installed.
3- Like this one they will probably need replacing every couple of years, much better to just have plug in USB Chargers.
At least the one in the video, which looks fairly well made, failed in a harmless way, no burn marks or any signs of it overheating.
They should design some sort of push - to -make switch so that it only powers up when a plug is pushed in, but I suppose it would push the price up too much!
I agree, but crucially they free up a plug socket. Useful were plug points are at a premium ie home office or kitchen counter.
While you're not wrong, people are just as likely to leave a regular USB charger plugged in and turned on all the time as well as their fridge, microwave, oven clock, clock radio, TV, sky box, modem router, smart devices, numerous pointless LED fairy lights and trinkets, the list is almost endless these days.
@@Dedubya- True, but at least with all those items if they go wrong or fail you can just unplug or replace them easily.
Sky HD boxes take ages to boot up if they've been unplugged, and the line management on broadband lines will detect a powered off router as a disconnection and drop the sync speed.
@@NOWThatsRichy yes indeed.... I fitted one of these in a corner for phones to charge and am unlikely to fit many or any more. I do agree that these sockets should last many years but with this added feature it's pretty clear their life span is greatly reduced. You might think the manufacturers wanted to sell products more often as there's little profit selling a socket once every 40 years :D
If this is running 24 7 in standby what consumption in watts would this consume ?. 2-3 watts?
Most USB power supplies are close to zero when in standby, certainly far less than 1 watt.
I like the idea of having these type of ports/connections in the wall socket but I still prefer an adaptor plugged in.
Mine has flickering light all the time and it only stops and just glows continuously when you plug usb. So irritating at night...
That blue foam is a thermal pad. I don't think it does much heat transfer to a plastic box hahaha
got it a few minutes before me! that was basically word for word what I was about to comment :)
@@TobyCowlesThanks m8!
I bet the idea is just so spread the heat around a bit from the tiny components to reduce hotspots. This whole device will be enclosed in a wall so long term it will get hot no matter what you try to do with it on the inside.
I thought it may have been there to dampen buzzing, for when it's on the opposite side of a partition wall which can amplify such things (especially shaver sockets)
Hi John, good video, As the excitement of being able to charge anything with U.S.B.dies down we realize that maybe installing into the actual infrastructure is not the best way of doing it!
I would favour your idea of a simple switch detecting if the U.S.B. plug is present!
But then again it is arguable that leaving a thing running is less wearing than switching on /off,
Still not a great way of doing this though as the socket is of a different reliability class compared to anything electronic!
Simple = reliable
Mostly.
Kind regards Warren
Hi John, this has happened to my socket too, I guess the only solution for a non electrician is to buy a new socket?
Are these available where you can turn the usb transformer on and off?.....seems a massive waste of energy ....cheers .
Not that I am aware of, all the ones I have seen are powered permanently.
@@jwflame hi, thought so, been looking around, was just curious as i need to buy a new charger and thought of these.....but not now ...cheers.
I find those pretty strange. The life span of an outlet can easily be 40 years. One could never expect such long life span from those. Even the USB standard varies. There now are fast charging. I think the USB-C connector will soon come the norm. These can have some use in public spaces where people can charge even if they do not have the charger with them.
no fuse on the usb charging circuitry?
component at bottom centre labelled DT2A-250V is a 2A fuse ;)
The problem I've always come across is the usb sockets don't work for everything you plug in. A usb is supposed to have 2 circuits, a 12v and a 5v and they only seen to have 1 when included in an electrical outlet or adapter unit.
Don't know where you pulled that from, usb has never had a "12v circuit" by default.
Standard setup for consumable electronic items, engineer it to fail within a rough timescale and sell more of them. Mostly the same with all IT equipment, post pentium3 era most of it fails within 5 years. I still have a compaq deskpro (p3 @ 1000mhz) which is fully working albeit now almost useless for all purposes, they don't make them like that anymore.
Like most modern electronics , built in obsolescence, I'm sure it's like that with android phones & tablets, they gradually slow down over time, even if you do a factory reset on them, they don't seem as fast as when you first bought them! 😞
Same, I've got lots of old computers and phones that still work fine but can't really be used for anything practical anymore. Software and websites just keep demanding more and more processing power just for basic stuff.
These are really easy to time the failure where you want because it will be connected 100% of the time and the aging characteristics for those caps etc. are quite well known. Allow a year or so for hot climates and you will hit the sweet spot of failulre nicely after the warranty period is over.
i also have a compaq deskpro p3 1ghz, works nicely, as for useless for almost all purposes nowadays, definitely not !
RUclips and facebook are too laggy on my old computers and I can't run modern games on them or software. Sure you can mess around with period correct software and web 1.0 stuff but definitely won't do as a daily driver.
MMMM not certain about always on not lasting "as long as it could do" (if switchable). 50 years ago when I was a mere boy learning my trade, there was a big debate around equipment. I was a telecomms type and by it's function almost exclusively our kit was required to be permanently powered.
At home Mum and Dad religiously "did the corners" every night to ensure that no plug was left unplugged.
The debate said that the majority of kit gets warm (or hot) and thus expands when it's on and contracts when it's switched off ... and this causes stress and failure to electrical components (in those days there was still a crossover with thermionic valves or transistors).
My experience both at work and at home was the PoP of doom when you switched something on. As a maintenance engineer things rarely died in service - more likely they just refused to switch on after being powered down.
When PCs and servers became more widespread we found the same principles applied. Upgrades that involved recycling the kit had quite frightening failure rates. Changing a HDD or RAM often included a new PSU.
There were magazine articles about it and legends about servers walled in by builders tat had been working for years (until the powercut!).
Skyscrapers were built with lighting circuits without user on off switches or power sockets, things connected directly to the mains. It was cheaper to power everything 24x7 than bother switching things off!
Then someone noticed that summer and winter were getting much the same temperatures and global warming dictated that everything should be switched off when not being used.
I think these sockets with USB should have a switch to turn it off the USB ports power
Why can't people use their supplied adapters? Lots of devices have powered USB when in standby too.
What would you trust? A USB outlet with a brand (MK, BG, etc.) & BS numbers on it or a random adapter bought from Poundland when the original Chinese adaptor of unknown quality let the smoke out?
Especially now that the EU have decided phones etc. can be supplied without adapters to save waste.
@@beardyface8492 I agree with what you’re saying. I’d rather an MK USB socket charged my devices than a Poundland USB adapter, however I’d always prefer to use a high quality adapter than anything else. I don’t see much purpose for USB sockets. I suppose they can help to free up sockets that would otherwise be used for adapters.
@@Lift.Tracker Typical consumer isn't going to shop carefully for a "Quality adapter", just grab the first one they pass at supermarket / petrol station / pound shop, while making the unwarranted assumption that trading standards prevent the sale of poor ones.
You or I might be careful what we buy, the masses grab the first thing that'll work.
Major advantage of outlets that incorporate USB is you can't misplace or step on them.
Here in Australia you can mix n match switches etc on different switch plates
I bit like MK grid switches I seem to remember
However you can also get a USB unit that will fit in a switch plate
So that’s I did I got a 2gang sw plate and put in USB power thing
Along side a single pole double throw switch, thus I can turn the power off when not in use
I’m the person who sent the socket to John. So the general thrust of the breakdown is that these things, no matter how much you pay for them, will have a high and short term failure rate because the USB outlet part is permanently live.
Would it be so cost prohibitive to have an automatic or manual switching provision?
Do you have any others installed?
uK8cvPAq Not anymore. The other one I fitted at my other son's house and he told me yesterday that if stopped working last summer and he replaced it.
No inrush current protection I suppose, the design from Masterplug 4 years ago are less smart and safe compared to chinese brands like Anker, Ugreen these days.
Didn't help that they were probably trying to charge both a phone and tablet with it at the same time.
Why would there be 2 sockets then?
@@Lift.Tracker A tablet needs more power to charge like the full 2.4A where a phone can happily charge on 500mA I will be slow but it will charge.
@@hawk_ness I see. Thanks. :-)
Let's be honest, these days we need a *lot* more sockets than are present in standard-build dwellings. On the face of it, USB sockets in a mains socket free up some desperately-needed mains sockets. But they have a finite life, so it's an expensive way of doing it.
Cheaper, and far more flexible, is a 4-way extension lead and a discrete USB supply or two (or three or four). If you go on holiday you can take a discrete USB supply with you but you can't take one of these things. If you decide the USB mains socket is no longer where you need to power your devices, it's a pain to move it.
The *only* place these things make sense is in cafes, airport lounges and the like where the operator wants to offer USB supplies to customers in a way that the customer can't walk off with the supply. Other than that they are a complete waste of money.
you can get usb power supply plugs with 'pass through' mains sockets so it doesnt use one up...i have one
as for the integrated usb/mains sockets, it would last better if there was some sort of switching so that when theres no usb plugs inserted, it disconnects the mains supply to the usb 5v power unit..
@@andygozzo72
The pass-through is definitely better than this thing. But I'd go for a 2- or 3-way adapter and separate power supply unless the pass-through were a *lot* cheaper. Because the power supply will die eventually, and you'll have to replace it, wasting the pass-through part.
Also, if you're worried about the power usage or want to maximize the life of the power supply, the adapter solution is better - you just unplug the power supply. With the pass-through you have to unplug the pass-through, unplug whatever was plugged into the pass-through and plug that back into the wall socket. Too fiddly.
@@andygozzo72
That would be expensive to do *right.* You'd want to switch the mains to the circuitry, and there's no way you could safely integrate the switch into the socket. So it would have to be a separate microswitch with an actuator arm that goes into a slot in the USB socket. Not impossible, but you're now looking at a special USB socket with a slot cut into the right place in the casing, which would cost more than an ordinary USB socket (extra machining step, not a standard part).
Another thing. People often leave the cable plugged into the power supply, even after they unhook their phone. So it wouldn't do much for most people.
Also, most modern phones have to be charged daily, and most people leave them plugged in overnight. So you'd probably triple the lifetime of the power supply to maybe 10 years. An ordinary mains socket has a much longer life than that.
It really doesn't make sense to use one of these things, even with a (hypothetical) USB switch. Except for places like airport lounges and cafes. For most people it's just another gimmick they'll end up regretting buying when it fails.
made my day this has.......NOT AAAAAAAAAAAAAGGGHHHHHH
On the bright side, the fact that USB-A is nearing obsolescence against USB-C doesn't really matter if the expected life of the these sockets is only 2-3 years! What a waste of money - we all have spare USB chargers that could do a better job. Just leave one plugged in and switch on when needed.
But USB is a really, really poor method of power transfer. The 5V USB system was originally only supposed to power low power devices like keyboards, mice and similar devices. And micro USB and the Apple connectors just don’t last or tolerate any abuse.
Fortunately USB hasn't been restricted to 5V for over 6 years now. Current USB power specs allow up to 20V at 5A with an appropriate USB-C cable, or 20V with up to 3A otherwise. That's plenty for most laptops, and more than enough for phones and tablets. But this assumes up to date USB, which these mains sockets aren't.
Paul Grimshaw - Fiddling with the standard to introduce USB-C does not solve the fundamental problems with USB though. In electrical power engineering, if you want to transfer any significant amount of power you need a number of things. One good quality connectors which have low resistance contacts with an appropriately large contact area for the maximum current that is required. The connectors also should mate firmly with no movement of the contacts or the connector once properly pushed home. The connectors should have strain relief for the cable. The cables used should have a good quality stranded copper conductor that has a suitably large cross sectional area so that the maximum current can be carried without any significant voltage loss. The original USB is a fail on all of these plus 5V is too low a voltage for proper power distribution. Yes USB-C tries to address some of these, but it is not that much better and is too little, too late (how long will it take to replace 5V USB given that an huge number of products and cables only meet the 5V USB standard are still being sold, never mind the huge number of existing devices) and it still fails to be a reliable good quality power connector IMHO.
Last reply - I'm not interested in an argument. Feel free to have the last word if you feel you must.
In fact this higher power handling capability is not restricted to USB-C. All existing USB cables support up to 20V at 3A, except micro-USB which is only really intended for 2A. This is adequate for most mobile devices with the exception of higher power laptops. Higher power (>18W) USB chargers were however not available until recently as there was little demand. But it's this constant evolution of technology which makes it pointless fitting USB to mains sockets - the point I was making in the original post.
I agree that if the sole requirement of USB connectors was to carry power then they would be more robust, but they also need to be small enough to fit easily into slim mobile devices and they need to be able to carry high speed data. In the real world a design is always a compromise to meet the current set of requirements.
I wonder why this failed. Well, obviously hot environment, running 24/7, mediocre components. I suppose the weakest link. . .
The pad looks like a thermal interface pad.. these are often tacky as shown and primarily meant for heat transfer between parts. It looks well designed, no doubt let down by those rubbish "ChangX" brand capacitors
D1 looks burnt see the white mark on it
The SOT-23-5 ICs on the USB daughter-board are Cell-Wise Semiconductor CW2003D USB charging port controllers.
Cell-Wise product page: www.cellwise-semi.com/en/ProductView.asp?ID=140
Data Sheet: majenko.co.uk/sites/default/files/pdf/1403493674-73686.pdf
Installed 5 LAP units (polished chrome) in the house and removed every one as they all failed within 24 months! 100% JUNK
Did they have USB ports? Didn't think screwfix brand were that bad.
Megger them all! These things should be banned asap. I will advise customers that I am putting an incendiary device inside their walls if they really want them. Second fix on new build will have standard sockets or nothing from me. If the customer then wants appliances installed instead of sockets it will be a separate job. Possibly with a signed disclaimer to state, "Well, I did warn you your house might burn down". Same goes for LED lamp drivers. Circuit boards everywhere! Thanks John.
I don't like usb sockets either the fact they are permanently on with no control hanging off a 32amp ring circuit, plus if they were to develop a fault they can leak dc and disable the rcd!
I suspect the 6.3V 1000uF output caps have gone lower capacity/high ESR even though they show no visible signs of failure, which limits the current this can output to much less that 2.1A. Small SMD caps rarely if ever fail.
What a horrid piece of utter sh*t. That applies to all incarnations of USB sockets, "WIFI" sockets and the like. I recently rewired a pub/B&B and refused to install these nasty things. How the hell they are "legal" in this day and age is beyond me! ;)
It's a genius move for the manufacturers of sockets - people will be buying new sockets because of a failed USB charger within.
Obviously it's a genius move for the manufacturer but a bad move for the planet ad the consumer..
2.1 amps total, iPhone uses 2.5 amps as does iPad... so either one would overload it.
Masterplug is part of British general.
USB wall sockets even from MK there is no way I personally would trust them.
It won't overload it. The devices negotiate the charging rate so only take what is available to them. You can happily charge a modern device on a 1 amp supply. It will take forever but you can do it.
equipment is 'supposed' to 'smartly' detect if a usb psu can supply the current 'normally' taken and if not, reduce it to level it can, thats what those chips on the usb socket panel are for..
Indeed. It's interesting to see that my USB power banks can happily supply a really high charging rate for my Pixel 3 whereas many wall warts charge slower. Also the stories of people trying to run Raspberry Pi's on cheap phone chargers that can't supply enough amps!
Again John complete crap
Just crapola from a trades person from the UK. Not at all an expert. Don't fall for the Uk accent.
Joseph Nicholas. Hmm 25 subs vs over 87k. Expert indeed.
Fuck off and leave then. John is a good friend top man.