But besides efficiency, i'd also like to see RF interference measurements on this one. There is a reason good power converters are fixed in one voltage output and use transformers...
High. VHF AC to DC conversion isn't in many devices because it is actually hard to get it to not cause issues with everything else on the same transformer (not even breaker).
Also you notice they use a lighter wire than most laptop power supplies would and no ferro loop at the end to reduce the noise to the device.
Maybe I missed it, but I don't think I saw a UL approval on the device. I also don't think there is enough room in the case to have a thermal cut out, and a fuse/breaker. Which you really need on a power supply.
I'd love to be wrong on all this. I hate carrying a brick (though mine is about the size of half a deck of cards).
The real thing for size is the transformer and other magnetics, which decrease with frequency, hence why this uses VHF frequencies. Output filters can also be made smaller at higher frequencies, and Ken Shirriff's iPhone charger teardown above shows a small ferrite ring _inside_ the charger case for high frequencies.
UL Approval is probably under on the "Production Timeline" (2/3rds down) under "Submit for initial regulatory certification (4 months)", which is set to begin now (Apr-May).
As for the wire thickness, it doesn't seem that much thinner than my Macbook Charger, which is also 65W. The production timeline on the kickstarter leaves them time to change to a thicker one.
The big question of course, is the feasibility of the VHF AC-DC conversion. FINsix have a paper (http://finsix.com/assets/files/FINsix_Tech.pdf) but its not very long or detailed, and I don't know enough to criticise it if it was.
One word of warning, the product timeline says you should expect your product in 7-11 months. That is a long time when you are talking about device compatibility. All Kickstarters have risks, but buying an accessory for a device that may not even exist yet is a larger than normal gamble. There were plenty of Kickstarters for iPhone accessories that didn't arrive until after they were already obsoleted by the lightning cable.
Will this work on your next laptop? Probably. Can the Dart team guarantee that the device will "work with all major PC brands" manufactured in the next year? Probably not. Is that risk worth the extra money you save on a pre-order? That is up to you to decide.
Unless some radical change happens to laptop power supplies in the next few months - a change from designs that have remained the same for over a decade - it's very likely this adapter will work with the newest (normal) laptops available when it comes out.
Also, laptops have very flexible power input circuits that will accept a wide range of DC input: they'll start running from ~12V (the voltage of an almost-dead battery), and go as high as the voltage specs on the input components allows - 25V (filter caps) is the usual absolute upper limit. Higher voltage means lower I^2R losses but manufacturers like to leave some safety margin, which is why 20V is somewhat of a de-facto standard given the parts available. The general power distribution circuits in a laptop are like this: there's a main power rail, whose voltage varies with battery voltage when running on battery, and is the DC-IN voltage with the adapter plugged in. The voltages for the CPU, GPU, chipset, etc. are all generated by DC-DC converters supplied from this main rail. There's a set of diodes/MOSFETs that wire-OR together the battery and DC-IN to the main rail, preventing current flow in the wrong direction. It also powers the battery charger.
I've read a lot of laptop schematics, and all of them use very similar power circuitry, often with the same components. The only real concern with device compatibility is in the ID schemes that some manufacturers use, either to "lock out" third party adapters or encode wattage selection. The simplest ones are nothing more than a resistor in the plug, different values for different wattages (IBM/Lenovo is one example). More complex ones use a 1-wire interface to an EEPROM or other storage element (Dell, Apple) (http://www.laptop-junction.com/toast/content/dell-ac-power-a...http://www.righto.com/2013/06/teardown-and-exploration-of-ma... ). Then there's all the others that have no ID at all, just +/- input, and these are the most compatible.
About the Dart itself: the technology used here (VHF SMPS) has been around for a long time in military/aerospace applications, where size/weight is more important than reducing switching losses.
"Unless something radical happens" - well yeh, the USB spec now supports the wattage required to charge laptops so I think that's a pretty radical change which will be coming in the next few months.
IIRC USB Power Delivery requires to provide 5V and 12V if you want to provide 20V. According to their FAQ question about compatibility with Microsoft Surface and Chromebook Pixel (https://www.kickstarter.com/projects/215201435/dart-the-worl... ) they don't have 12V support. Probably they are not ready for USB 3.1.
I'd guess 12V is for lower-power devices, where (slightly) cheaper 16V-rated (the next step below 25V) capacitors can be used. The other parts (switcher ICs and MOSFETs) are usually rated for much higher, and the system would be fine with a 20V input if it weren't for the 16V caps.
E.g. the EEE 1000HE uses a 12V adapter, and it has 16V caps in its power circuit. Probably the same for the Surface/Pixel.
That is simply not true, the USB spec now supports charging of laptops over USB and I would be very surprised if over the next few months it didn't become fairly common in new laptops - it adds an extra USB port to a laptop and is very inexpensive.
Charging via USB adds extra complexity and there is nothing wrong with the existing system, so I don't think it will have as much adoption as you predict. OEMs rely on manufacturers like TI to provide ICs and reference designs, and for the moment it doesn't look like there's a highly-integrated solution for USB-PD.
> and there is nothing wrong with the existing system
Yes, there is: it causes massive electronic waste because of incompatible chargers. Expect the new EU regulation that covers phones etc. (that replaced "voluntary" measures) to be expanded to cover laptops too, or at least for manufacturers to get threatened with changes to th regulation, if manufacturers don't voluntarily switch to USB once suitable chargers start being widely available.
There is nothing electrically wrong, and while I agree that there have been many different connectors used and having one standard would be great, manufacturers do tend to settle on one of relatively few standard connectors (the majority being barrel plugs of various sizes.)
However, the solution is not a grossly overcomplicated standard like USB. It is a 20V barrel plug. Maybe if you want to get really fancy, include a resistor on a third pin for wattage encoding. Standardise on that instead - or pick an existing size - there are enough to choose from already ( http://en.wikipedia.org/wiki/Coaxial_power_connector#Standar... ).
This is a somewhat uninspiring attitude. There was nothing wrong with the PS/2 mouse and keyboard plugs either, nor the 25-pin printer plugs, nor some barrel plug for charging phones. But the problem is there were so many different things that all needed their own plug. Now there's no mouse plug or phone plug or printer plug since they all use USB. Laptops with a standard non-USB plug will still add to the duplication and inconvenience just like those old keyboards did. You won't be able to charge your phone with your standard barrel plug laptop charger, so you'll still have to carry two adapters when you travel.
There was nothing wrong with the PS/2 mouse and keyboard plugs either, nor the 25-pin printer plugs, nor some barrel plug for charging phones.
With the exception of the phone charging example, I would agree. The PS/2 protocol is vastly less complex than USB, and parallel ports are so simple they can be used as GPIOs with ultra-low guaranteed latency. Phones migrated to USB because they already needed the bulk data transfer capability along with power, and USB made for a good fit.
You won't be able to charge your phone with your standard barrel plug laptop charger, so you'll still have to carry two adapters when you travel.
The Dart has both USB and a barrel plug, which is the same as many other aftermarket adapters. (They could've made this more obvious in the marketing material, e.g. by showing USB devices plugged into it and not just laptops most of the time.)
I'll choose a laptop with a big robust barrel plug, and one that can be powered from anything outputting 12-24VDC, over one with a USB socket and requiring complex negotiation protocols to even start consuming power. It's the KISS principle. Standards that try to do everything don't tend to do any one thing particularly well, and introduce unnecessary complexity.
You don't need to implement full USB for USB power delivery. USB's data transmission is not used in it at all.
Detection of power delivery plugs is mechanical for standard A connectors (their male standard-A connectors are 1.3 mm longer so they could be inserted deeper in female power delivery connectors than conventional connectors so metallic shield connects detection pins) and based on detecting resistors and capacitors between ID pin and ground and power pins for other connectors.
For voltage negotiation new simplified bus and protocol was invented; it uses high frequency transmission on the same pin as power.
Traditionally all manufacturers have been using a little bit different connectors on the laptop. Also tho voltages seem to differ a little bit. Hard to see any other real reason for this than to make switching to another brand a little bit harder and to make a few extra $$$ by selling accessories.
So even if adding a new USB port for charging is cheap and easy, the manufacturers might still have reasons not to do it.
No. USB 3.1 supports power delivery at 60w or 100W, easily enough for most laptops. Yes, they aren't used at the moment, but it's definitely presumptuous to suggest that laptops won't use USB any time soon when the technology is so nearly in place.
I don't think that there is much that the major PC brands can do to prevent the device from powering their future devices. However, you are right that a certain a certain amount of risk exists and I don't think that one would actually save a lot of money by ordering early. Given that they use no custom electrical components (according to the project description), $89 seems like quite a hefty price. I assume that by the time the device is mass produced its price will be lower due to pressure from competitors.
Note that it powers a usb device. Every single iOS device and every Android device that I know of have a USB on one end of the cable.
Also, is anyone really innovating in Laptops these days? Is there a reasonable expectation that something like "A new type of charger" can even happen in the next 12-24 months?
To get around the Apple patent, they should have made the device compatible with a cigaratte lighter socket or the old-school plane power socket, which would enable customers to buy the official Apple Travel Adapter. This is how HyperJuice has done it.
Additionally, If you have a MacBook Air it doesn't seem significantly enough smaller than the 45W MBA power brick - not to justify the higher price, anyway.
Yes, their magnetic power connector is patented. US7311526. (Not that it ever stopped the Chinese who have had magnetic power connectors on their electric kettles and skillets for years before Macbooks even existed from cloning it, but that's a different story...)
Deep fryers sold in the US also have magnetic power adapters.
Apparently the thing with this (as magnetic power connectors have existed for a long time) is that there are, at the very least, claims in Apple's patents that differ from previous examples and patents[1].
So basically the novel thing isn't magnetic power adapters.
Looking quickly through the claims they don't appear to cover having a circular magnetic connector - instead it's specified (eg in claim 1) that the connector has 2-fold symmetry and in other claims that the 3 connections are arranged linearly.
The other point you might "attack" the claims on (ie in designing around them) appears to be the inclusion of "bias". Mind you it's not entirely clear¹ what is meant (without referring to the description) by "biased" here: claim 6 suggests it means sprung in some way.
Edit: looking at a couple of pieces of the prior art http://www.google.com/patents/us7311526#backward-citations it seems the main innovation in the Apple claims is probably the symmetry / reversible nature of the connector. There were already circular connectors, eg the cited US3808577, so Apple's claims may have had to work around those - hence the construction including the symmetry clauses. Seems a magnetic connector is well doable even without any need for invention, just based on expired patent disclosures.
Your throwaway remark is ridiculous - a quick visual comparison will show you that they're completely different interfaces designed for different products.
> An electrical plug and receptacle relying on magnetic force to maintain contact are disclosed. The plug and receptacle can be used as part of a power adapter for connecting an electronic device, such as a laptop computer, to a power supply. The plug includes electrical contacts, which are preferably biased toward corresponding contacts on the receptacle. The plug and receptacle each have a magnetic element. The magnetic element on one or both of the plug and receptacle can be a magnet, which is preferably a permanent rare earth magnet although electromagnets may also be used. The magnetic element on the plug or receptacle that does not include a magnet is composed of ferromagnetic material. When the plug and receptacle are brought into proximity, the magnetic attraction between the magnet and its complement, whether another magnet or a ferromagnetic material, maintains the contacts in an electrically conductive relationship.
What part of that abstract doesn't also describe the magnetic connector on a Japanese electric water kettle?
Abstrats are meaningless. You could patent something that who's abstract is "It's a club which you use to beat people with." as long as the actual methods are novel.
I am left wondering what's novel/patent-worthy about a VHF power converter. It sounds like an incremental improvement on current systems (which typically operate in the 100kHz-1MHz range), and the link in the Kickstarter doesn't have much substance to it. Anyone know what I am missing?
This looks legit backed by MIT patents and grad students, but I wonder why a group making this "breakthrough" is going directly to Kickstarter to raise hundreds of thousands of dollars, instead of selling the technology directly to companies like Apple or Samsung and make tens of millions of dollars.
Because Kickstarter is used to get the resource to accelerate the business which they may well eventually sell to Apple or Samsung for far more than they raise from kickstarter. (See, e.g., Oculus Rift.)
> That's a fairly cynical and negative point of view that goes against the core ideas on which Kickstarter was created.
I don't think it really does. Kickstarter is expressly a way of getting resources people interested in offerings to launch them when the funds to start the to launch the offering wouldn't otherwise be available, in order to create sustainable businesses that would otherwise not get started because of lack of access to funds to start them.
Obviously, one of the very common things to do with a viable business once it is running -- and one that maximizes the return for people who are best at (or most interested in) launching things -- is to establish the business, sell it to someone interested in running it for the long term, and use the proceeds to start more things.
While particular exits might bother some people, I don't see how its contrary to the core ideas on which Kickstarter was created, or a sad thing. People who are well suited to getting the ball started on something aren't always best suited for later stages.
Whatever kickstarter was meant to be it is clearly being used for nothing more than preorders far in advance and you don't even have a guarantee you will ever get the product you preorder. In exchange for that risk and tieing up your money for such a long time before the product is available you possibly get a product that might not otherwise exist. The truth is you don't really know if it wouldn't have existed without kickstarter or not.
Yeah, this particular product is nice, but maybe I'm suffering from kickstarter-fatigue too. This is nice, but not unique enough to warrant special effort (and waiting months) to get it though.
> "I find it sad that we'll have to always consider that particular scenario from now on."
People have had to consider that scenario for pretty much any business. Especially fledgling companies, as they might get bought by someone else or they might simply go bust. There's nothing specific to Kickstarter about this.
Kickstarter's core goal was to help inventors bring their ideas to life and help them fund initial production.
It has since evolved into a platform that often helps their most engaged users find new ideas and get early access to new technology.
Both of these processes benefit from one another, so I don't think that "it goes against the core ideas on which Kickstarter was created".
The implications of the technology are a lot bigger than laptop supplies and I am sure they know that. Laptop supplies seem like a good way to raise some cash without dilution while they work on harder problems.
Maybe they want to go down the occulus rift approach, use kickstarter to gauge whether theirs a market, use this buzz as a platform to attract VC, then sell to one of the big players in a few years time?
Regarding market and buzz, that's exactly what they're doing. They certainly have proved their market. The rest really depends on their long term goals.
This looks very much like the Rommoss car charger. I have one for my laptop. This gets its source from 12V DC instead of AC, but the rest works the same. Usb port and automatic voltage sensing circuitry. You just need a specific cable for whatever you're charging. Plug in a standard usb cable to charge your phone, you get 5V. Plug in an adapter cable for your Dell laptop, get the desired 19V (or whatever your laptop needs).
there are 2 things made of ferrite in an adapter, for different reasons. There is a ferrite ring around the input cable so that EMI don't go upstream in the socket, and this one they will probably keep. The other one is the core of the transformer and they say they don't need it at that frequency.
At the headline, I had the kneejerk doubt that they could fit laptop-level power in such a small adapter, but they claim that's exactly why their product is interesting.
Nevertheless, I'm going to wait for the first wave to prove itself and for them to iron the kinks out (there are always kinks in a first-gen HW product). As such, I hope this is a true "kickstarter" that starts company momentum and isn't, like too many others, a one-shot deal.
Very nice product. I have an (fairly) old compaq laptop with a built in adapter and even though its heavier than it should be, pluging the cable is a delight.
I use the HN facebook feed (yes I do) and there is no direct link on it, just the video (maybe specific to KS?).
Also the music in the video is distracting. It is way overcompressed.
Very polished kickstarter but I'm left wondering, do I really need an $80-$200 charger? The MacBook air charger is already pretty small and my phone lasts all day without the need to recharge. Although the tech inside it might be novel and interesting I really don't see the cost vs benefit as a consumer.
This looks like a funded, experienced, hardware team with an already finished product. Are they only using Kickstarter for exposure? If they're looking for validation/upfront manufacturing costs they should be doing pre-orders instead of "crowdfunding"
Pre-Order gives you a right to obtain the product or at least get some money back in case the company folds and there are assets left, usually even before the investors see any money. You're a customer. Kickstarter gives you "you're a backer" and in case the company folds you get nothing.
Except in this case, if the company folds, there are likely to be no assets left, as the majority of the funds will be going to pay for manufacturing and the inventory needed to drive it. I would contend that your risk profile is almost, if not completely, identical, and it's the risk of doing early business with a very young company.
That might be an argument against Kickstarter in general, but it isn't a good criticism of any particular use of Kickstarter, especially of one like this which appears highly likely to succeed in producing the promised product.
I think it's even a better criticism of this particular case: If this kickstarter really has such a low risk of failure, why don't the investors bear that risk and go for preorders?
I've been thinking about the overweight (and overpriced) laptop adapters for a while and reading about this project made me very happy.
Could anyone suggest some scientific reading on their claimed very high frequency power conversion (or any similar technology)?
Right now the smallest laptop adapter; also has no AC cord; is the http://www.fsplifestyle.com/product.php?LID=1&PSN=771 FSP Twinkle. It's the same 19V 65W adapter this one claims to be. It's made by a reputable power supply maker. While I applaud smaller and lighter adapters I would be extremely wary of an unknown startup meddling with power supplies. Also, regulatory approval is hell and while they do mention it among the risks I am also wary of that. I will pass this Kickstarter...
As someone who's travelled a lot, this looks like a cool upgrade.
But man, what I wouldn't give for an adapter that make it easy to pack by having some clever and clean way to wrap the cord. It doesn't look like this one does.
Good idea but the implementation is gravity challenged which will wear the plugs and the sockets used over time. It would be better to reduce the length and get it closer to the socket.
Wait so what's the advantage of this over the free adapter your laptop came with? It says its smaller, and yes it does look marginally smaller (not enough to make a difference to me personally), but is that it? You can charge another USB device with it, but my Surface Pro charger offers that too. Am I missing some other USP that would make it worth buying this as an upgrade? I can see this being useful when licensed to laptop manufacturers, but not as an aftermarket upgrade.
I know this is Hacker News and we love startups, but I think this would have been a better licensing play. It just doesn't seem like its a good business model to try and create all these adapters for old and new laptops. That compatibility list looks really annoying from a consumer standpoint. Its just not something I want to look up every time I'm in the market for a new laptop.
That's just for now. From the looks of the laptop connection they're angling for a buyout/license from iGo, who already makes a zillion nub-ends just like theirs.
I saw this at CES and it was one of the very few products I saw the entire event that made me say, "I want to invest in this company." I wanted to take one home!
Sadly this isn't directly Apple compatible. It says the mac version they buy an off the shelf apple power adapter and then connect them for you or something. I guess the magsafe connector is patented?
I would hope Apple was working on a smaller power brick, its kind of silly when my power adapter is almost as heavy as my Macbook Air 13". yeah, i know #firstworldproblems
I've know this team for some time (also an MIT grad). I'm so happy they have pushed their product and have moved to the Bay Area.
The Dart might look like a small device but its an incredible feat -- specially since it needs to safely work with all laptops and devices. Very excited about the future of the product.
Apple power adapters are not grounded if you use the short plug (the cable is grounded) and they supply up to 85W. You sometimes get the slight tingly feeling when touching the case.
It's pretty common for power adapters to be double insulated. Which in a way is very useful if you're traveling in e.g. continental Europe, where you can just buy a two prong "europlug" cable to use instead of the NEMA one which fits in sockets of varying design.
it's not mandatory in most countries for various reasons. The most simple one is that none of failures modes of the adapters connect the main to the laptop without doing a short first (unless you bought a fake one in which case all the bets are off).
> Global Dart: You live abroad and you want a Dart. This reward is for you. The Dart will work internationally, but you'll need a plug to match your outlet. This reward includes the Dart PLUS a plug adapter for your region. Your Dart, your color holds for this offer. Choose your favorite from among our signature Kickstarter colors. Please note the later estimated delivery date. Not MacBook compatible. Shipping is included.
(Emphasis added)
It seems this is in fact fit for most of the world.
(Yeah, Apple doesn’t do prices below €20, but it’s a pretty nice and compact charger. It’s longer than the US charger, but very flat, which I think is a better form factor in many situations.)
All of this is to say that these adaptors are super annoying, look ugly, add bulk and are easy to forget, so never an ideal solution.
It depends on whether or not they mean "a plug adapter" as being 'swap out the existing plug with an interchangeable fascia' or an external adapter such as tourists use. The latter is not a solution.
First gen hardware product that's innovative and accomplishing something the hardware manufacturers haven't yet. A slightly uglier version isn't really a big deal when, if they're successful, they'll be able to start offering proper international versions. Remember, this is a hardware Kickstarter. The number of different and short production runs to support the variety [1] of sockets makes their proposal far more reasonable and cost-effective (for the first production run). This way, they make one device modulo the outside casing and the limited run Macbook compatible ones.
Sticks a long way out of the wall. How much, lest's see: the size is given in cubic inches, how useful - not.
It's also only 50% of the size of my current adapter, not a quarter, although to be fair, that one is only 33W. Does have a UK plug though! Dart plus plug adapter is probably no smaller.
Global Dart: You live abroad and you want a Dart. This reward is for you. The Dart will work internationally, but you'll need a plug to match your outlet. This reward includes the Dart PLUS a plug adapter for your region. Your Dart, your color holds for this offer. Choose your favorite from among our signature Kickstarter colors. Please note the later estimated delivery date. Not MacBook compatible. Shipping is included.
Imagine what that thing will look like with a gigantic UK plug adapter ;)
Moreover, the North American ungrounded plug is one of the easiest plugs in the world to pull out of a socket. So if I plug Dart into a adapter for any other part of the world, plug the adapter into a socket, and then try to pull it back out, Dart will separate from the adapter and leave the adapter in the socket. It happens all the time when American electronics are used abroad, and it's extremely annoying.
Gee. So they will just add a plug adapter? They won't actually make a Dart with an E-plug? That sort of ruins the thing for me, particularly considering a plug adapter plus a power adapter in a wall outlet is asking for all sorts of trouble.
I've barely had success with plugs that weren't this heavy.
with normal usage - 4.5 hours. But if I run something in dGPU - I can burn through battery in like an hour.
Under windows they told it will get better battery life mostly because of better drivers support. But I never tested it.
This is Dell Precision M6600. This one and most other Precisions will consume similar amount of power from PSU. Not sure why all the downvotes. Even MacBook Pro I have requires 85W
[1] http://www.righto.com/2012/10/a-dozen-usb-chargers-in-lab-ap...
[2] http://www.righto.com/2012/05/apple-iphone-charger-teardown-...