New circuit design allows for elimination of laptop charger brick

Dec 24, 2013 by Bob Yirka report

(Phys.org) —Power electronics maker FINsix Corporation has announced the development of what is being called the world's smallest laptop adaptor—one that is just a quarter the size of traditional models and just a sixth the weight—it comes as a standard wall plug, eliminating the "box on the ground" format so familiar to laptop users.

The new adaptor has come about due to the development of a new circuit design by MIT professor David Perreault—it's able to run at higher frequencies (between 30MHz and 300MHz-a thousand times faster than conventional adapters) due to a power reclaiming scheme he developed. The result is a 65 watt that can be used to charge a variety of laptops or other devices such as smartphone or tablets (because it comes with a 2.1A USB connector)—it can even charge more than one at a time.

FINSix says the tiny adapter is just the first of what will be a whole new line of power electronics devices based on the new circuit design—from AC/DC converters to power controllers in devices ranging from air conditioners to more efficient electric motors—all courtesy of the increased . The new design allows for recycling power that in traditional designs is lost, preventing the loss of efficiency that typically occurs with other circuits when upping the frequency range. Representatives for FINSix say the new design (which uses what they call Very High Frequency conversion technology) leaps over conventional barriers and will pave the way for more efficient that are also smaller and lighter.

The new adapter which doesn't appear to have a name or price yet, is likely to be extremely popular among laptop users (when it becomes available for sale sometime mid-2014) as it will allow those who tote laptops around to downsize their carrying case and to leave chargers for other devices at home. The company plans to unveil the new adapter to the public at next month's Consumer Electronics Show in Las Vegas where it will be featured as an Engineering Award winner in the Portable Power category.

Explore further: Charger specification for notebooks to be available early 2014

More information: www.finsix.com/

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OZGuy
3.4 / 5 (5) Dec 24, 2013
Dell can't even make a standard charger fitting across it's models let alone a standard charger. Doubt they'll be adopting this!
goracle
4 / 5 (1) Dec 25, 2013
As I finally start to see fewer of the Macbooks with the big brick at the end that blocks the other outlets, they come up with another way to put it back at the end where it can most easily interfere with sharing.
antialias_physorg
3.7 / 5 (3) Dec 25, 2013
Dell can't even make a standard charger fitting across it's models let alone a standard charger.

It's more profitable to make non-fitting chargers with proprietary plugs and non-standard voltages. That way the customer is forced to buy a new one when he loses one instead of reusing one from other machines they may have (or old ones).

Yes: standard chargers would be neat for the customer - but companies aren't in the market to deliver what the customer wants, now, are they?
Whydening Gyre
5 / 5 (4) Dec 25, 2013
Dell can't even make a standard charger fitting across it's models let alone a standard charger.

It's more profitable to make non-fitting chargers with proprietary plugs and non-standard voltages. That way the customer is forced to buy a new one when he loses one instead of reusing one from other machines they may have (or old ones).

Yes: standard chargers would be neat for the customer - but companies aren't in the market to deliver what the customer wants, now, are they?

Another prime example is printer ink cartridges...
loneislander
5 / 5 (1) Dec 25, 2013
Frequency? Power converter? So, we modify power with something other than winding ratios and diodes... ok, how about a little blurb about that -- I can understand the Higgs but I have no idea why there is a "frequency" to a power adapter other than 60hz (or whatever your local hz is).
italba
5 / 5 (2) Dec 25, 2013
These are not traditional power supply with transformer, diodes, capacitors and transistor voltage regulator, these are full electronic devices. Grid power is firstly rectified by diodes, then an electronic switch (thyristor) send short impulses of that power to a small winding. The energy stored and released by the winding goes directly to the computer, phone, or whatever we need to recharge. The width of the impulses, controlled by an integrated circuit, gives the output voltage. Usually, as the article saids, the frequency of the impulses is in the 40 - 100 kHz range now.
hangman04
5 / 5 (2) Dec 26, 2013

It's more profitable to make non-fitting chargers with proprietary plugs and non-standard voltages. That way the customer is forced to buy a new one when he loses one instead of reusing one from other machines they may have (or old ones).

Yes: standard chargers would be neat for the customer - but companies aren't in the market to deliver what the customer wants, now, are they?


Unless legislation enforces it. Like EU is trying with phone chargers
MR166
3.3 / 5 (3) Dec 26, 2013
"Frequency? Power converter? So, we modify power with something other than winding ratios and diodes... ok, how about a little blurb about that -- I can understand the Higgs but I have no idea why there is a "frequency" to a power adapter other than 60hz (or whatever your local hz is)."

In simple terms they have to convert line voltage to the filtered DC voltage that the battery pack needs. To accomplish this at low AC line frequencies take big components. Turn the 50 or 60 HZ line voltage into higher frequencies and the voltage reduction can be done with smaller components.
shavera
4.7 / 5 (3) Dec 26, 2013


Unless legislation enforces it. http://thenextweb.../#!qGYPg


Didn't they already do this with the micro USB standard that everbody but Apple uses?
Eikka
not rated yet Dec 27, 2013
It's more profitable to make non-fitting chargers with proprietary plugs and non-standard voltages.


You can't standardize laptop power brick voltages because the voltage you need depends on how many battery cells you have and their specific chemistry. Otherwise you'd need to include a second power transformer inside the laptop itself to shift the charging voltage to the appropriate level, which would cost more, weigh more, and make the laptop bigger.

Lithium cells are nominally 3.7 volts, but they range from anything between 3.2 - 3.8 volts per cell, and the actual voltage varies between 2.5 - 4.2 volts, where the full charging voltage multiplied by the number of cells there are, plus about 1 volts, determines the power brick voltage. For a big laptop with 6 cells, it can be 26 volts, for a small laptop with 3 cells it can be 13.6 volts... etc. etc.

And the proprietary plugs naturally follow, so you won't plug the wrong charger with the wrong voltage in.
antialias_physorg
5 / 5 (1) Dec 27, 2013
You can't standardize laptop power brick voltages because the voltage you need depends on how many battery cells you have and their specific chemistry.

The power you need depends on the components that need them (CPU, harddrive, etc.). These voltages are VERY standardized. Adding more batteries doesn't change the required voltage (since it is trivial to switch from a serial configuration to a parallel one for charging).

You always have to charge with a voltage that is slightly larger than what your batteries nominally have. The voltage depends on the chemistry - only. All laptops use Li-ion batteries, therefore a one-size-fits-all charger would easily be within the realms of possibility for manufacturers (as the above article demonstrates).

The whole thing with the different chargers, and especially the different plug configurations, is a marketing ploy. Nothing more.
Eikka
5 / 5 (2) Dec 27, 2013
I have no idea why there is a "frequency" to a power adapter other than 60hz


Switching mode power supplies operating from the mains are all internally AC-DC-AC-DC converters that increase the frequency of the line voltage because the higher the frequency the smaller the transformer can be.

Since the energy has to be stored in the magnetic field of a transformer or an induction coil for the duration of the AC waveform cycle, lower frequencies mean more energy has to be stored somehow, and that means bigger heavier metal cores for the inductors. With high frequency, the same amount of energy is put through in smaller parcels and the device can be built smaller.
Eikka
not rated yet Dec 27, 2013
Adding more batteries doesn't change the required voltage (since it is trivial to switch from a serial configuration to a parallel one for charging).


Added complexity costs money.

But if you're willing to put your money where your mouth is, please do draw up a charging circuit that charges six cells in parallel and discharges them in series, simultaneously, seamlessly as the laptop is operating because the machine may at any time switch between power sources or draw power from both at the same time.

Your minimum cell voltage will be about 2.8 volts given safe tolerances for charge levels, and you need to output at least 12 (10.8), 5 (4.75), 3.3 (3.1) Volts with minimum energy loss, circuit board area and complexity. You also have to accomodate a varying number of cells between the typical 4-6 cells in a laptop. Figures in parentheses are minimum tolerable voltages.

Of course it's possible, but you won't pay for it.
Eikka
not rated yet Dec 27, 2013
Oh, and mind that any semiconductor switch like a diode or a BJT added in series to a circuit will lose you about 0.6 volts, so if you have a string of six cells with one such device for each cell, you lose on the order of 15% of your battery capacity because your added switches cause the battery to lose some effective operating voltage.

That means the difference of going from a 6 hour battery to a 5 hour battery, which doesn't look very good on the brochure against a competitor's laptop that doesn't use such trickery simply to gain a standardized power brick.

All that could be avoided by making power bricks with adjustable output voltages and interchangeable plugs, like they already do with generic aftermarket power bricks, except the problem is that people will inevitably try to use the PSU with a machine that requires more power than it can supply, and switch in the wrong voltage, causing destruction of both devices.
Eikka
not rated yet Dec 27, 2013
Another added complexity is that when the cells are not in series for recharge, you have to add a circuit that counts and controls how many coulombs of charge is put into each cell, because once you switch them in series for discharge again they're all going to be drained the same amount regardless of what you put in.

Ordinarily when the cells are in series to charge, each cell would get charged the same amount and the cell voltages would vary slightly, but that's not an issue. If the cells were charged and discharged in parallel, that would solve the problem as well, but then the battery voltage would be too low for some of the parts and it's more difficult to regulate the voltage up than down efficiently.

So you see, it's not as cut and dry as you'd think it was.

All laptops use Li-ion batteries


What about those that use Li-poly? Besides, the cell voltage range of a li-ion battery varies between the different formulations.
casualjoe
not rated yet Dec 27, 2013
I've been trying to get my head around the resonant switching psu, the regulation works in such an ingenious way, yet efficiencies are under 90% in all the ones I can find, there must be a way to improve them but I'm yet to know how.

Not to take away from the professor guy in the article who managed to recoup the reactive losses from such high frequencies and convert it to useful regulated power, how the buggery did he do that? Amazing.
Eikka
not rated yet Dec 27, 2013
the regulation works in such an ingenious way, yet efficiencies are under 90% in all the ones I can find, there must be a way to improve them but I'm yet to know how.


I think the key issue is that they depend on free oscillation in some part of the circuit to be resonant, so they're highly sensitive to environmental variations, manufacturing tolerances, slew rates of switching etc.

casualjoe
not rated yet Dec 27, 2013
They're so complicated for such a great idea haha

I would like the LiFePO4 as the new standard in cell chemistry, they have a slightly lower voltage but good discharge rate, great stability and a (so i've read) longer lifetime than regular Li batteries, so the LIFePO4 delivers more energy over the total lifetime of the battery. No brainer suerly but I could imagine something like the customer wanting the longest operating time possible in their advertisement brochures.
24volts
1 / 5 (1) Dec 27, 2013
Adding more batteries doesn't change the required voltage (since it is trivial to switch from a serial configuration to a parallel one for charging).


Added complexity costs money.

But if you're willing to put your money where your mouth is, please do draw up a charging circuit that charges six cells in parallel and discharges them in series, simultaneously, seamlessly as the laptop is operating because the machine may at any time switch between power sources or draw power from both at the same time.


Electric bike battery packs that use lithium type batteries have been doing it for about 5 years or more. The actual charger circuitry if often in the computer itself and not the power pack to begin with. The battery equalizing circuitry is in the computer or on the battery pack itself.
Eikka
not rated yet Dec 27, 2013
so the LIFePO delivers more energy over the total lifetime of the battery.


Yes, but on the other hand they are less energy dense, so for the same weight in batteries you get less run time, and the added life of the battery isn't really of any advantage when everything else about the machine starts to fail by year 5 or 6 anyways. There's about a 1/3 chance that the highest quality laptops on the market today will last you more than six years in use, and a 95% probability that you'll ditch yours for a better one in less than four years anyhow.

Eikka
not rated yet Dec 27, 2013
Electric bike battery packs that use lithium type batteries have been doing it for about 5 years or more. The actual charger circuitry if often in the computer itself and not the power pack to begin with. The battery equalizing circuitry is in the computer or on the battery pack itself.


Not quite the same though, unless you intend to insist that electric bikes may be running around with the power cord attached. Theirs is a much clearer system of states - the battery is either charging, or discharging, and no power is being drawn past the battery, so in theory you could even do with mechanical relays that physically switch the cells in and out. Would save you the semiconductor losses.
casualjoe
not rated yet Dec 27, 2013
Generally, with laptops, there is a high chance the battery fails first, closely followed by the clumsily cracked screen, LFPs are more thermally stable than Li ion and would reliably last a 6 year life of a laptop. Small extra battery weight for a longer/reliable life is a worthy compromise but then I'm no macbook air fan even though its efficiency does impress me, I'd rather buy a 2 year old, second hand laptop and become forced to replace parts of it after roughly 4 years when something breaks.
Eikka
not rated yet Dec 27, 2013
Generally, with laptops, there is a high chance the battery fails first, closely followed by the clumsily cracked screen


The most common laptop failures are probably caused by spilling a drink in the machine or the eventual buildup of dirt that causes it to overheat and keel over.

For actual faults in the machine itself, most commonly it's the hard drive, the motherboard, and the screen hinges and/or connecting cables. The mac style unibody designs are specifically prone to motherboard failures because all the flexing of the outer casing is transmitted directly onto the circuit board.

As for the difference in weight, an LFP cell is roughly twice as heavy as something like NCA per watt-hour.
davidivad
not rated yet Dec 28, 2013
interesting new idea. I see how increasing frequency enables a smaller device. you see similar things happen with ac motors which are basically transformers anyway. I do wonder if this comes at the cost of life expectancy though. I am surprised that laptop charger specifications are not more regulated than they are now. hopefully this will reduce the overall variety of jack types in the future. universal adapters are my point in case.
Captain Stumpy
5 / 5 (1) Dec 28, 2013
@Eikka
(re: replacing laptops)

...add to all that the software issues
from all the build-up of useless/malicious software on the laptop to the "newest/greatest" marketing ploy that so many fall for.

And then add the fact that so many are still not very tech savvy ...
Whydening Gyre
5 / 5 (2) Dec 28, 2013
@Eikka
(re: replacing laptops)

...add to all that the software issues
from all the build-up of useless/malicious software on the laptop to the "newest/greatest" marketing ploy that so many fall for.

And then add the fact that so many are still not very tech savvy ...

Cap'n - It's the ol' "baffle 'em with BS" ploy...
Eikka
not rated yet Dec 29, 2013
Yes: standard chargers would be neat for the customer - but companies aren't in the market to deliver what the customer wants, now, are they?


The problem is that the customers want two things: good and cheap. Nothing should cost anything, but it should have all the features.

So how do you fill this contradictory desire?

What happens instead, the market delivers what the customer actually needs, dictated by what they're willing to pay for. If the customer doesn't really need a cordless drill with metal gears, they will opt for a cheaper one with plastic gears. If they know they need it to last, they'll find a brand and model with metal gears, and pay the extra buck. You know the saying, the poor can't afford the cheap.

But then people who bought the cheap drill invariably complain and blame the market for making crappy products; their real complaint is that the features aren't provided for free and they don't want to invest their time to shop around for a better product.
antialias_physorg
not rated yet Dec 29, 2013
The problem is that the customers want two things: good and cheap. Nothing should cost anything, but it should have all the features.

That can't really be the reason since even a single manufacturer has multiple different charger types for their various laptops/tablets. if it's 'go cheap' then they'd all be the same (i.e. the cheapest of the lot). And it's not like chargers come with any features besides 'charge a battery' that would distinguish them. Even if: I cannot think of a feature that would require different voltages.

What happens instead, the market delivers what the customer actually needs

No. The market delivers NEVER what the customer needs. It only, ever delivers what makes most profit.

Case in point: Your 'crappy product' example. If the market would deliver what the user needs then they'd refuse to make crappy products. The user WANTS cheap products, but the user NEEDS good products. By your very example the market delivers what the user wants - only.
Eikka
5 / 5 (1) Dec 29, 2013
That can't really be the reason since even a single manufacturer has multiple different charger types for their various laptops/tablets.


I don't see how that's relevant. The manufacturers usually have one model of charger for one model of laptop, and if two laptops can use the same charger then they won't waste money making two different kinds of chargers.

I cannot think of a feature that would require different voltages.


I already explained at lenght why different laptops use different voltages: because they have different number of cells of different chemistry, and it's not trivial to have one universal charging voltage for all.

No. The market delivers NEVER what the customer needs. It only, ever delivers what makes most profit.


So what does the customer "need" then? How do you define that?

The crappy product example was pointing out that a person does not necessarily need a drill that lasts forever if they're just drilling a couple holes for pictures.
Eikka
5 / 5 (1) Dec 29, 2013
By your very example the market delivers what the user wants - only.


In a sense. But what the user ultimately wants is everything for nothing. That's what we all want.

The market delivers exactly what the people at large want to pay for. You can try to introduce a laptop with a universal charger that can accomodate different voltages and power, but it will cost more to design and manufacture, and therefore cost more to sell. You can then watch how many people actually want that by observing how many of your potential customers go to your competitor for a laptop that is $10 cheaper because they just don't care.

I cannot think of a feature that would require different voltages.


Also this point: if your laptop has less battery cells, it doesn't need as much power to recharge, so you can build a smaller charger of say 35 W or 65W instead of including a 120 Watt brick with every laptop just in case.
Eikka
not rated yet Dec 29, 2013
My charger for example already is this small:

http://i.walmartimages.com/i/p/00/88/48/40/01/0088484001481_500X500.jpg

But there's not that many laptops that can charge and operate with 40 Watts, so even if it had a standard connector, I couldn't really charge any other laptop with that.
Eikka
5 / 5 (1) Dec 29, 2013
The market delivers NEVER what the customer needs. It only, ever delivers what makes most profit.


Here's the full point:

You can't define what the needs of people are, because need is subjective, so you can't go all Karl Marx over the market and dictate what everyone shall buy for what purpose. Instead, what people need is what they deem they need, which is ultimately a compromize between what they want and what they can afford. Then, if you didn't need or want it, why'd you buy it?

If there is a genuine need for something then there is profit to be had in making and selling them. If people just say they want something, like higher quality cordless drills, but won't actually buy them because they cost more, then there was no need for them and the market won't bother to sell them.

Mind you, this definition of need is not the physical need of food and shelter because we're talking about luxury items, which is anything non-essential - like laptops and power tools at home.
alekseyt
not rated yet Dec 29, 2013
Really enjoyed the discussion ! Thanks Eikka.
Captain Stumpy
not rated yet Dec 29, 2013
The problem is that the customers want two things: good and cheap. Nothing should cost anything, but it should have all the features.


@Eikka
I wonder if this is a cultural thing or something learned... There are some who believe in the value of work, especially good work. When some purchase, they realise that there is a market, and that a product takes manufacturing, and do NOT mind allowing a person to make a profit off of something.
Eikka
not rated yet Dec 29, 2013
When some purchase, they realise that there is a market, and that a product takes manufacturing, and do NOT mind allowing a person to make a profit off of something.


Most people just don't have any idea how much things cost to make or why.

The free market is supposed to work by having informed people make rational purchases so that they don't pay a thousand dollars for a 10 dollar hammer simply because they didn't know it cost so little. Secondly, it should always have free competition to ensure that producers cannot pump up the prices that ridiculously high above the cost of production in the first place, because where the customers lack information they can always compare prices.

But the real market doesn't work this way because of legally instituted restrictions on information such as patents and copyrights, lack of proper regulation, and due to subsidies and regulations lobbied in that work against the consumer.
Eikka
5 / 5 (1) Dec 29, 2013
And of course because people are lazy and don't bother to do any research to find out what they're really buying into, and companies actively trying to hide information.

Proper regulation in terms of laptops could for example include mandatory reporting about warranty returns, so that all manufacturers must report the number of cases a product is returned to manufacturer for repairs for each model to establish a failure rate. Consumers could then refer to this information in choosing what brand of laptops they'd like to have.

Apple fans could then shut up about macs never breaking down, because they do break down just as much as the Dells they always bring up in comparison, and people would practically stop buying HP and Acer if they knew how much they do break down.

Such statistics are already collected, but the information is patchy because you have to rely on third party retailers to provide it.
Captain Stumpy
not rated yet Dec 29, 2013
And of course because people are lazy and don't bother to do any research to find out what they're really buying into, and companies actively trying to hide information.


now THIS i totally agree with... and just may well be the core of the problem you are addressing.

as for the "apple" debate... anyone that knows a good IT tech and has an internet connection should be able to end this debate in a matter of minutes.
Eikka
5 / 5 (1) Dec 29, 2013
do NOT mind allowing a person to make a profit off of something.


There's also the point that business corporations and companies are not people. They are more like chemical reactions that happen, like fire; when you combine heat, fuel and air you get a self sustaining flame - that's your marketplace. It doesn't respond to good will and courtesy - if you as a consumer go to the market without a clue, you will get short changed and burn your fingers.

Similiarily, if you as a society institute the free market and expect it to do its thing alone and just sit back and relax, you're effectively setting your house on fire to make it warm. It will do just that.

That is to say, the free market does exactly what you let it do. Of course the anticapitalist then argues that this means it has failed and should be replaced with some form of command economy, but in keeping with the analogy that's like warming your house by lighting matches one by one to keep the fire in check: ineffective
Eikka
5 / 5 (1) Dec 29, 2013
and just may well be the core of the problem you are addressing.


The problem is called cost of information. It takes time and effort to work out what products there are and what their differences are. If the difference in value is small, then the rational person won't bother because they would have to work more than they gain to find the optimal product. People just don't stop to argue about the merits of one $20 cordless drill over another, because the time wasted would be greater than the difference in quality or price. (unless you have more time than money)

With laptops, you might spend effort to find a good model, but still you won't put much thought over small improvements like a universal power suppy because what does it really do for you that is valuable?

That is, assuming the universal power supply is actually a valuable feature instead of a penalty, like getting a 120 Watt power brick for a tiny netbook just because it's the same thing for the bigger models.
antialias_physorg
5 / 5 (1) Dec 29, 2013
There are some who believe in the value of work, especially good work. When some purchase, they realise that there is a market, and that a product takes manufacturing, and do NOT mind allowing a person to make a profit off of something

The idea is good. In reality it only works if the consumer can spare the cash. Companies, banks, governments, ... have become so adept at fleecing the people actually working that they are left in a state of permanent 'bare minimum' (or at the very least in a state where they think that what they may not have enough to cover future situations). In such a situation people are forced to go for cheap products above quality products.

The (upper) middle class could have supported that model. That class has all but disappeared in most countries.
(The rich certainly don't go for a 'pay more than absolutely necessary' approach - and where they do its for products that aren't of interest to anyone else, like luxury yachts/cars/houses).
Captain Stumpy
not rated yet Dec 29, 2013
antialias_physorg
(The rich certainly don't go for a 'pay more than absolutely necessary' approach - and where they do its for products that aren't of interest to anyone else, like luxury yachts/cars/houses).


that may also depend on the individual in question.

The idea is good. I... go for cheap products above quality products.


there is much truth in that... from where I am standing, anyway.
The question I would ask is: is it cultural or learned? Is it fixable?

Personally, I never mind paying for quality. But I dont run in the same circles as most people, nor do I have some of the same requirements/needs as others... and i NEVER make a purchase without research. the only spur of the moment purchase i might make is for chocolate, so...
jibbles
not rated yet Dec 31, 2013
Frequency? Power converter? So, we modify power with something other than winding ratios and diodes... ok, how about a little blurb about that -- I can understand the Higgs but I have no idea why there is a "frequency" to a power adapter other than 60hz (or whatever your local hz is).


agreed. good point.
Eikka
not rated yet Jan 17, 2014
In such a situation people are forced to go for cheap products above quality products.


I repeat the old adage, the poor cannot afford the cheap. The cheapest option usually turns out more expensive in the long term.

There is a concept of unnecessary quality as well, or irrelevant quality. A product that is better than what is necessary is essentially a waste to the individual, but also to the society because more resources have been spent in making it in comparison to what good ever comes out of it. This is what the free market is supposed to optimize for as well.

Again point in case: a person who buys a cordless drill to make a few holes to hang up picture frames in his house. Does he really need the more expensive drill with metal gears, instead of the less expensive drill with plastic gears? In both cases, he's not going to be keeping it as a heirloom for his children - after drilling a few holes it's going to end up abandoned in the attic and eventually thrown away.