It's a pleasant surprise to see my old power supply article on the front page of HN today. I'd never given much thought to power supplies before researching that article and there's a lot more to their history than I expected. In particular, Robert Boschert seems like he should be a HN hero for running a startup from his kitchen table that had a huge (disruptive?) impact on the power supply industry.
There are a bunch of comments below about wall chargers. I investigated wall chargers too - see http://righto.com/charger - and there's a lot more inside them than you'd expect.
Is there any way for me, without destruction or an oscilloscope, to work out how reliable my ~$15 USB chargers are? What about portable USB batteries? (3.7V LiPo + converter = large amounts of money apparently)
Edits after going through the article and comments:
* Weight - hard without a reference weight, but I'm going to guess that cheaper chargers are going to be lighter
It seems like the chargers will also react to the quality of the power coming out of your socket - a comment in the USB charger article references 110V power on Indian trains being a bit hit and miss. I'd say this is the same for power on BC ferries too.
Would quality (noise levels?) of mains power be why my Lenovo laptop got a hell of a lot hotter on a Qantas A380 aeroplane? (which supplies 110V at 60Hz). It's normally plugged into Aussie 230V (240V) at 50hz.
There's no easy way to tell how good a charger is just by looking at it. Generally you get what you pay for - if you order a "Genuine Apple iPhone OEM charger" on eBay sent from Hong Kong for $3, I guarantee you it will be a low-quality fake. But a $15 charger from a brand-name manufacturer should be reasonable quality.
Fake chargers will copy the UL marks and labeling, so that doesn't help you. Of course, if it says "Designed by Abble" or "Designed by California", that's a pretty good indication of non-quality :-) (I've seen both of those on fake iPhone chargers - it should say "Designed by Apple in California".)
The one thing people notice from bad chargers is their touchscreens malfunction when plugged into the charger. Bad chargers let through enough electrical noise to overwhelm the very small signals that touchscreens create.
When you say your laptop gets a lot hotter at 110V, do you mean the charger or the laptop itself. Chargers are generally a bit more efficient at 240V than 110V, so I wouldn't be surprised if it is a bit hotter. But the output is exactly the same, so I wouldn't expect the laptop temperature to change. If it's hotter, I suspect ventilation is different or you happen to do CPU-intensive applications on planes.
>When you say your laptop gets a lot hotter at 110V, do you mean the charger or the laptop itself
I mean the area of the case directly above the power input got a lot hotter than usual. This was tested over a couple of hours of the flight while the laptop was running in both high performance mode and the lower power modes
Most people have some idea of how heavy piece of electronics of certain size should be, many fake chargers/supplies are surprisingly lighter than that (sadly, even some known original Nokia and Samsung chargers seem too light to me, so this is not valid test)
Good thing to look for is presence of some name of manufacturer. Absutely no name => unsafe, Obscure or semi obscure Chinese manufacturer => probably OK, Well known global brand => depends (and depends on what the charger is for, nobody is going to manufacture fake Delta-branded charger for iPhone, but fake Delta-branded power bricks for various networking equipment are fairly common).
Power quality on input is certainly an issue, but only for totally out of spec inputs. Small wide input SMPS (like these for laptops) just run hotter on lower voltages because of their internal construction (lower voltage => higher current => higher losses).
Here's a little lesson I've learned about claims of theft of revolutionary products: they're always false. Innovation and invention are continuous and gradual processes, with numerous precursors and multiple independent and simultaneous origins. It's basically evolution. There is no such thing as intellectual theft, nor are there revolutionary products, nor are there genius or original inventors.
There's just dumb plodding incremental innovation by connecting past ideas together into useful products.
Everything is a remix. There are no revolutionaries, only winners writing their own versions of history.
Good entrepreneurs copy. Great entrepreneurs steal.
What has been will be again, what has been done will be done again; there is nothing new under the sun. Is there anything of which one can say, “Look! This is something new”? It was here already, long ago; it was here before our time. No one remembers the former generations, and even those yet to come will not be remembered by those who follow them. (Ecclesiastes 1:9-11)
Perhaps a fair observation for someone living in biblical times. (And with no knowledge of several technological upheavals that came before or after.)
OTOH one can do what people tend to do with religious texts rightly or wrongly, look beyond its obvious falseness and charitably reinterpret this. Maybe this is even an expression of conservation of mass; that we are not creating newness, simply re-arranging matter. Or perhaps it says that despite technological change (possibly deemed surface-level change even if nontrivial), some essential part of life and society continues to resemble its former self.
I will say this part is much more accurate:
> No one remembers the former generations, and even those yet to come will not be remembered by those who follow them.
I'm often bummed out by descriptions of famous and important people from 100+ years ago. Name after name of people you've never heard of, all deceased. It can be depressing to think of our present, or even our future, and the future of those that will come long after us, as appearing in the same light.
> Name after name of people you've never heard of, all deceased. It can be depressing to think of our present, or even our future, and the future of those that will come long after us, as appearing in the same light.
Yep. Most of the book is along these lines. I don't always understand it, but sometimes it really hits home. Like this:
"I hated all the things I had toiled for under the sun, because I must leave them to the one who comes after me. And who knows whether that person will be wise or foolish? Yet they will have control over all the fruit of my toil into which I have poured my effort and skill under the sun."
In a community that values "do"ers so highly it's depressing to consider where all that work ends up. How many products are wiped out, how many companies bought and dismantled and how much of the code you pour your heart and soul into now will even be around in 10 years?
This is only true until something new comes along. History repeats itself...until it doesn't. After a long period of relative stability, the human population is exploding, for example.
Of course, in terms of human motivation, human suffering, sin and virtue, indeed: there is nothing new under the sun. But the instruments of suffering change. Rebecca Sedwick killed herself at the age of 12 because of cyber-bullying. 12-year-old girls have certainly killed themselves for being bullied before; but now the bullying occurs online. Is that new?
Governments have always sought absolute information, and absolute power, over the people: power seeks more power. But technology has allowed the US government to seek out this power in secret. Is that new?
You can always define things such that there is nothing new: Diana Nyad swam from Cuba to Florida, the first person to do so - and at the remarkable age of 64. But was long distance, open-water swimming through shark-infested waters new? No. Striving hard for what may seem to other people to be a wasteful and arbitrary token of accomplishment? No, that's as old as time itself.
(Interestingly, and I think quite remarkably, you can go the other way: in a sense, everything is new. Eating this apple? I have eaten apples before. Others have eaten other apples. But I never eaten this apple, right now, before now. Part of me doesn't like this reductio, but another part of me thinks that it's not ad absurdum at all.)
Indeed. The Everything Is A Remix series has been great for showing this. The 3rd part actually covers Apple and their "inventions", too, but all are very interesting, and even enlightening:
The idea that everything is a remix is a bit like moral relativism. The fact that things sit somewhere on a spectrum doesn't mean we should ignore the distribution of things on that spectrum.
> The idea that everything is a remix is a bit like moral relativism. The fact that things sit somewhere on a spectrum doesn't mean we should ignore the distribution of things on that spectrum.
Tangential to your main point, but that analogy is pretty bad because that's actually nothing like moral relativism, as moral relativism doesn't hold that "everything is on a spectrum". The divide between moral relativism and absolutism isn't between morality being continuous valued and binary valued, but between it being subjective and objective. Anything about morality falling on a spectrum or not is orthogonal to relativism.
You're right of course, it was a poor analogy for exactly the reason you cite. What I was probably thinking of was the somewhat related trope: "society is to blame" for the actions of a criminal. It may be that many criminals have shitty childhoods, but plenty of people who have shitty childhoods aren't criminals. The Mac team may not have invented the Mac from nothing, just as Intel didn't invent the transistor, but insofar as they did recycle old ideas, what they created was markedly better in many ways than what they received, and that's how we measure innovation (I think).
Steve Jobs, in particular, always sounded like he was delivering a sales pitch in his public comments. Maybe it was deliberate; maybe it's just that he ate, breathed, and slept "the game."
I think you have to view his inaccurate and hyperbolic statements in that context and not take his public comments wholly at face value.
We tend to worship heroes. Thus, when we learn that something is cool, we go looking for a lone person who can be identified as the "genius" or the "inventor." If somebody can set themselves up as such a hero, then inventions will be attributed to them by their followers.
You quote selectively from Jobs. Here's the part that's actually his claim:
>> "That switching power supply was as revolutionary as the Apple II logic board was," Jobs later said. "Rod doesn't get a lot of credit for this in the history books but he should. Every computer now uses switching power supplies, and they all rip off Rod Holt's design."
Jobs wasn't just claiming Holt's power supplies were built like those in oscilloscopes, but that it was practically the ancestor of all modern PC PSUs.
The article conclusively dismantles that claim.
P.S. The oscilloscope reference seems to be a Red Herring. From the article:
>> One puzzling aspect of power supply discussion in the book Steve Jobs[1] is the statement that the Apple II's power supply is "like those used in oscilloscopes", since oscilloscopes are just one small use for switching power supplies. This statement apparently arose because Holt had previously designed a switching power supply for oscilloscopes,[82] but there's no other connection between Apple's power supply and oscilloscope power supplies.
It could also be that Steve Jobs had incomplete information. Holt told him he designed such and such (maybe he should have just said implemented), without giving him references for who did it before. Jobs did not bother to find out and the false idea that Holt invented it stuck to his mind. Maybe just an honest mistake, but then due to lack of rigor.
Did you read the article at all? Switching power supplies were common and extremely well-known in industry at the time, and had been used for mini-computers for years. There was nothing truly "revolutionary" about the Apple II's power supply and it's design was not substantially copied by other micro-computer power supplies. None of Jobs' claims are backed by even the slightest shred of evidence.
I think the "revolutionary" part doesn't mean revolutionary alone, but in the context of computers.
There are also several possible structures of switching power supplies, so it may involve a new structure, or a new way of regulating the output, or just saving on components.
Revolutionary may be an hyperbole, but it probably had some novelty factor as well.
Edit: ok the article explains the patent awarded to the power supply, nothing too fancy. Oh and a TO-3 transistor, brings memories.
a lot of interesting articles turn up periodically, as new generations (or cohorts) discover them all over again. I love this, and I'd never have found it if reposted. It's a pity there aren't a few curated archives for gems such as these.
I have never had the impression that Apple had revolutionized power supplies. Honestly, I am happy if I am not forced to use a three-pin plug and the power supply works reliably.
Just saw the movie "Jobs" where some time is spent on the features of the power supply. Having not heard of this before, I went searching and found this page. It is older and associated with the release of the original book biography, but still interesting. Figured others might share a curiosity about this facet of the story...
And not just a list of links, but with commentary by the author detailing why he thought it important and where specifically to look! It's almost as much fun reading through the reference list as it is the main article.
What does this figure of speech mean? I've seen this before, where someone puts the word "Dat" before a noun, and I have absolutely no idea what it means.
Like I know "dat" can be slang for "that," but "That Reference List" makes no sense to me either.
I believe the intended meaning is that the subject in question is so awe-inspiring that the speaker can only briefly direct their audience's attention before lapsing into wordless reverie.
Speaking of which, the Jobs biography by Walter Isaacson is not. He is totally technical clueless. And most of the book is just copy-pasting of different other better books about Apples history in the 80s/90s.
Wall warts used to work as a step down transformer and a linear regulator (http://en.wikipedia.org/wiki/Linear_regulator). The step down transformer is the big brick like piece of the wall wart.
More modern transformers are switch mode supplies (http://en.wikipedia.org/wiki/Switched-mode_power_supply). Switch mode supplies (like the OP describes) are smaller, run cooler, and (nowdays) cheaper than linear supplies.
The main thing that's happened is IC manufacturers have made switch mode controllers cheap, and reliable. As a result, most wall warts are going away, to be replaced by switched supplies.
There isn't any significant hardware-wise difference in most SMPSs between today and say 20 years ago. The main cause for essentially every wall wart being SMPS is simple economies of scale and globalisation:
* Difference between power supplies for different countries amounts mostly to plug shape, you don't need different transformers for 110 and 230V.
* The whole power supply is smaller and lighter, so it's cheaper to ship it around the world
* SMPS is simplest way to meet requirements on cos phi, efficiency and idle power in some jurisdictions.
In end when you are designing product that does not have any special requirements on power quality (like precision instruments) or customer expectation that it should be big and mostly empty (home AV stuff) it is simply cheapest to order SMPS wall-warts from China in bulk.
It makes me happy that there's some technical discussion on this thread. One thing I'd like to add is that linear power supplies are better for AV systems because switching power supplies have a lot more RFI and electrical noise, which can be a problem when you're dealing with small analog signals. (This noise is also why cheap wall chargers can cause your phone's touchscreen to malfunction, since they have very small signals which can be overwhelmed by noise.) So they aren't using linear power supplies just to make the AV box more impressive, but for functional reasons. (See www.ti.com/litv/pdf/snaa057b which explains why unregulated linear power supplies are good for audio systems.)
My point with AV equipment was that these things tend to have somehow standardized sizes and mostly empty cases. Thus shipping cost tend to be dominated by "volumetric weight" and not real device weight. EMI/RFI from SMPS is valid concern for these applications but not as significant as it is often claimed to be.
More significant issue is cost: you need power supply that supplies slightly weird voltage rails that essentially has to be custom, even off the shelf SMPS modules tend to be significantly costlier than wall warts and you don't have any reason not to just stick big transformer in there (even more so because you essentially don't care about regulation of the more loaded rails)
WRT 20 year old supplies, there are pessimistic, yet true, comments to be made WRT the likelihood of the UL registration being fake, or the RFI suppression components being replaced by jumper wires, and value engineering to run hotter to require quicker replacement (electrolytic tech WRT handling heat hasn't improved much.
There is one tiny correction to your post that I can make; the reason why you order SMPS wall arts from China is because there are 20 places to compete on "12 volt, 2.1 mm coaxial jack, 1.5 meter cord" so you can play mfgrs off against each other, but there's not so many places willing to play internal mounting games WRT exactly where each plastic mounting post is located.
IF internal SMPS had something as effectively standardized as NMEA electric motor mounts, then you MIGHT see more internal power supplies because competition would be cheaper.
I think also the EU put in a regulation limiting idle current draw (phantom load). The linear units leak when not in use, you can feel the warmth. Switching units don't leak significantly. That forced switchers while they were still slightly more expensive.
If the switcher was $0.50 more expensive, you were getting a linear even though it would cost you an extra $2/year in electricity. Consumers demand cheap initial cost in their electronics. The EU regulation just forced the upfront cost.
Ah, right, thanks! So old wall warts were like the power supplies the OP describes right at the start, and the change we've is that newer wall warts are like a scaled down version of the ones he spends the rest of the article describing.
And I would add that switching power supply tech has been around for decades (hello, desktop PC tower cases!). It just wasn't used as often in consumer devices because they were more complex (more parts, trickier to design) and
there simply weren't many consumer devices around that required so much power _and_ portability.
I would argue laptops were the killer app as far as switchers are concerned. Once they showed up and got popular, designers newly had reasons to design switchers more often.
A lot of the old wall warts are "Type 2", which means transformer, rectifier, reservoir capacitor -- no regulation there at all. With light or no load, the output voltage can soar (such as, 18v DC no-load from a nominal 12v DC @ 300 mA wart). The switchers are regulated, so you get what it says on the tin.
As transistor switching speeds get faster, the switching supply can operate at higher frequencies, which means less energy has to be stored per cycle, which means smaller components can be used.
The claim "...and they all rip off Rod Holt's design" is classic "reality distortion field" salesmanship. Lesson learned: don't be humble when you're the pitch man.
Even the claim that every other computer maker used switching power supplies certainly wasn't true at the time of the Apple II; its direct 6502-based contemporary the Commodore PET 2001 had a standard heavy transformer bolted to its thick metal chassis and large capacitors under the hood.
So because Jobs once admitted to being a bullshitter, his claims are beyond scrutiny? Even when those claims are repeated as fact by secondary sources?
This article isn't grinding an ax. Rather, it's an interesting investigation of a little examined aspect of computer history that happened to be kicked off by skepticism of a claim that actually turned out to be false.
> So because Jobs once admitted to being a bullshitter, his claims are beyond scrutiny?
Yes. In the real world, we call this "taking it with a grain of salt." Think about how many other interviews with other celebrities you've been concerned about fact-checking.
> Even when those claims are repeated as fact by secondary sources?
This is not and should never be Jobs' problem.
> This article isn't grinding an ax. Rather, it's an interesting investigation of a little examined aspect of computer history that happened to be kicked off by skepticism of a claim that actually turned out to be false.
It's concern trolling. It's pseudo-intellectualism analogous to people who bring up Ben Franklin's mistresses whenever someone brings up his inventions. And it's ridiculous that someone would write a fully-researched analysis of an off-handed comment whose clear intention was to praise an employee for his contributions.
His claims aren't beyond scrutiny, but they get far more than they deserve compared to other tech CEOs. Almost anything positive about him or even apple, is shouted down, whereas anything negative is held up as 'scrutiny'.
Let what shit go? Factual inaccuracies? Fabrication of history?
No, we can't let that go. So long as these erroneous facts still get circulated then they deserve to be debunked, forcefully.
That doesn't mean there is any malice intended towards Jobs or his legacy, but facts are facts.
If you think that debunking Jobs' bullshit claims will inevitably have a deleterious effect on the historical perception of Jobs as a person, well that's on Jobs for being a bullshitter, not on anyone trying to ensure that people don't have a false view of history.
This is like saying 'Apple didn't revolutionize tablets - Microsoft did'.
It's pretty ignorant to keep attacking Apple for not 'inventing' every aspect of every technology they use. That simply is not how the industry works for any company.
When Apple 'revolutionizes' something they do so by understanding how a particular technology can be applied to deliver value to users. Period.
This same logic applies to Google. It's hard to dispute that they 'revolutionized' search, and yet they did not invent crawlers, minimal search interfaces, or even using backlinks to rank pages. What they did was to combine these things into a brilliantly engineered solution.
This is yet another linkbait semantic argument that gains attention only because it attacks Apple.
Did you even read the article? The fact that you are speaking in generalizations strongly suggests that you did not. Steve Jobs made some very specific claims, the article debunks them in great detail.
Have you ever worked with C-level executives before? They frequently speak in soundbites like this because they have to have a 30,000 ft. view over their company while at the same time picking out highlights that can be used in interviews like this.
What's really notable is how much shit Steve Jobs gets for completely off-the-cuff comments like this (I mean, we're talking about oscilloscopes here), yet no one bothers to mention the fact that here we have a CEO giving credit to one of his employees by name. Does the CEO of your company even know your name? When's the last time a CEO has given anyone else recognition in an interview?
If I was that engineer it would make me very uncomfortable to have a public figure overstate my accomplishments. Especially since part of the claim is that all current designs "rip off" this one (which isn't actually true) and that history book authors unjustly fail to acknowledge this.
>It's pretty ignorant to keep attacking Apple for not 'inventing' every aspect of every technology they use.
The article doesn't attack Apple for not inventing every aspect of every technology they use. In fact, it doesn't even seem like you read the article. The article attacks a specific claim made by Steve Jobs.
There are a bunch of comments below about wall chargers. I investigated wall chargers too - see http://righto.com/charger - and there's a lot more inside them than you'd expect.
Let me know if you have any questions.