the white brick is also not using ground!! so nice idea, thanks!

vreesh

It would seem that the metal nub that holds on Apple's power connectors acts at the ground for the three-pronged cable. I guess that this trick would provide the same amount of grounding at using the two prong connector (which is no grounding), so it must be about as safe, as long as the bootleg-attatched cable isn't deformed or anything.

michaelper22

for the guys thinking that this will fry your macbook, no.

I've been using this for a while now - because I bought my macbook elsewhere and now I'm using the euro plug so it wouldn't fit (the US plug). luckily a cable like that (exactly the same in the picture) from my sony camera chargers (which I have quite a few) has the connector compatible to the wall sockets.

there's a lot of appliances/gadget chargers that have that female-end plug that's perfectly compatible with the macbook charger. also, you can also use the iphone usb charger that comes standard with it if you don't need that extra 5-10metres -- but in my case the iphone charger comes with the US plug shape as well :P can't use that.

so it's perfectly fine, although it does not have the ground wire incase it gets zapped by lightning. in that case I unplug it.

iBSOD for iPhone

@2-7offsuit: re: "How can I tell if the cover screw is grounded?"

To tell if the screw on the outlet is grounded, get a three-prong outlet tester. This is a small device (just a few $) that plugs into a three-prong outlet and has red and green lights that tell you if the outlet is wired correctly and if the ground is valid.

Then install your two-to-three prong adapter, putting the outlet cover screw through the adapter's ground terminal ring. Use your tester to see if the resulting three-prong is valid.

It probably will be, but there were some houses without ground. Some houses will have ground in some areas and not others.

moe52

Okay, the little bit with the fold-out prongs is called a "duckhead". I didn't make that up.

Also, since the duckhead doesn't have the ground plug, the power supply obviously doesn't require it- end of discussion.

I got a kick out of the comment about "positive, negative, and ground" in a wall outlet; thanks for the laugh! Oh, you were serious? Umm...

rustybadger

I was waiting for time to settle before commenting. Apple has recently included a graphic in the retail power adapter boxes showing this exact arrangement, lest Lam be accused of, I dunno, innovation. Since he keeps such excellent company, from Mr Pash to the ArsTechnicas, it should be easy to realize my disdain is entirely jealousy.

I just want to say I used to call them boombox cords.
And, now I can brag that I found the best deal(at the moment) on the most convenient length for this type of cord:
[www.cyberguys.com]

Sacrilicious

@moe52: Thanks. How can I tell if the cover screw is grounded?

2-7offsuit

@samuel1613: re: "...whenever I get a 3 prong cord, and a 2 prong outlet, I just bend the 3rd prong (ground) back and forth till it snaps off .... Realistically (and I mean realistically) am I in danger?... are we talking like 1 in 50, or like 1 in a billion chances I'm gonna die from doing this?"

1 in 23,456.78.

OK seriously, now. If your appliance has an internal fault or gets wet and connects a voltage to the device's chassis, then you can touch the appliance and you would be a nice handy path to ground. Bzzt.

No one can guess a probability. For something like a drill or a toaster, especially an older one, would be higher than, say, a computer. In the presence of water, probably higher risk.

The risk is not high but if you routinely snap off the ground prong just because you're too lazy or cheap to get a three-wire extension cord, then you should probably re-think that.

moe52

@2-7offsuit: The advice is simple: If an appliance has a three-prong plug, you should use three-prong outlets and extension cords. If you use a three-to-two-prong adapter, use the adapter's ground connector (a ring that attaches to the outlet's cover screw). If the outlet cover screw is grounded (yeah, "if"), then you have some protection.

moe52

@samuel1613: I'd kind of like to know the same thing. Currently I have to run an extension cable across my house to plug in the powerstrip for my tv and other media to a 3-prong outlet. It would be nice if I could safely just use one of those adapters to plug the 3-prong powerstrip into the 2-prong outlet right behind the tv. I just don't want to take the chance of burning down my entire apartment building.

2-7offsuit

The connectors are IEC standards - C7 'figure 8' is the male end, C8 is the female end.

Details at Wikipedia [en.wikipedia.org]

The 'kettle plug' used on most desktop computers is another of the IEC standards, C13/14.

The point that is missed in the tip, and not well made in the comments is that this tip works really well when travelling - C7 cables come in every local socket type. I keep ones for US, 2 pin Euro plugs, UK plugs and take the cable I need for the country I'm going to. Saves on bulky plug adaptors.

nicb

Hey everyone, whenever I get a 3 prong cord, and a 2 prong outlet, I just bend the 3rd prong (ground) back and forth till it snaps off, then I continue as usual. Certainly some people are cringing at the thought, others are likely unconcerned. I've done this to a corded drill, my laptop (dell), and a few other things that I find myself unplugging and replugging to various spots in my 1960's era house that doesn't have 3 prong outlets everywhere. Realistically (and I mean realistically) am I in danger? I mean I know there is greater danger than before, but are we talking like 1 in 50, or like 1 in a billion chances I'm gonna die from doing this?

samuel1613

The small attachment to the Apple power brick that allows you to plug the brick directly into the wall is prone to break over frequent use. The prongs that swing out, over time wear down and don't always make the connection when swung out. Replacements are impossible to buy unless you have an apple dealer in your neighborhood. No online outlet, not even apple themselves sell them. Which is why I find this tip useful.

NadineOrion

@grant0: They're not hard to find. Well, an actual official Playstation cable may be hard to find, but the exact same type of cable can be had from Radio Shack for about 5 bucks. It's a fairly ubiquitous connector; my cheap portable stereo uses the exact same cord.

HeartBurnKid

As someone else said the ground only connects to the power supply and not the computer. It may just be there for shielding reasons. Given there isn't any exposed metal on the case, and the voltage sent to the laptop is not referenced actual ground (or neutral or whatnot) I don't see any big risk.

The library I go to has a dire shortage of receptacles, and the ones there are are inconveniently placed. I bring along a 3way splitter, and a 10ft, two prong extension cord, that I cut the the end off that prevents you from inserting three prong plugs. I now get a compact extension cord, and with the splitter I don't have to worry if there's no free receptacle.

Note: DO NOT remove the ground pin from the laptop power cord. It is best to use a grounded supply when possible.

I also bought a couple Europe->North American power tip adapters at the dollar store. The Europe side also has slots for North American plugs, and it raises the ground pin enough to not have to cut out parts of the extension cord.

johnsmith1234

@exp: Toshiba is magical.

Anyway, this cable appears to be a PS2 cable which is actually really hard to find now. The PS3 cable is totally the wrong type. That is, it wouldn't fit.

grant0

Two friends and co-workers bought a 17" Mac Book Pro each last week, and both included a pair of plugs; one nubbin that stuck the power supply directly to the wall, and one long cord. Official Apple parts. The nubbin stays in the laptop bag, and the cord runs down the back of the desk. No need to crawl behind desks or buy extra power supplies.

legerdemain

The connector is an unpolarized IEC C7.
[upload.wikimedia.org]

legerdemain

Thats a really cool concept.
It also works with an xbox power cord as well, I just tried it.
Nice for use as an extension cord.

boomerang42

Two things to note about Mac power adaptors:

1) You can pull the plug off and stick absolutely any figure-of-eight power cable (like the PlayStation one, above) on there. This is about ten times cheaper than paying for the Apple travel kit, and if you leave your travel adaptors at home, you can walk into any electronics store and pick up a suitable cable.

Also, it gives you much more freedom in positioning the adaptor. A UK mains plug sticks out about 3/4 of an inch from the wall and the figure-of-eight cable exits straight to the ground. By comparison, the Macbook mains adaptor sticks out 3 or 4 inches and the cable exits perpendicular to the wall.

2) You can take the Mac travel plug and stick it into any device which wants a figure-of-eight cable. This turns trailing chargers, such as the PSP charger or many digital camera battery chargers, into compact wall warts.

Sockatume

First, the ground is attached to the brick. While the cable looks like it only has two conductors, the ground attaches to the metal button-looking thing.

Second, the ground doesn't leave the brick. I was quite surprised to discover this while I was repairing my wife's charger. The ground attaches to the shielding in the power supply, but there are only two conductors sent from the brick to the computer (+ - DC).

So there shouldn't be any danger here. The design is puzzling, though.

Krylez

Comment on Hack Your Mac Laptop Power Cord ... laughing at the idea that the US plug is too big to carry around conveniently (even the three prong version) - come on over to the UK and have a look at ours; and we don't have a two-prong option. More seriously, the ground does seem to do something in European Macs - I used to do what the hack suggests (the reverse of Eliot's tip) when in the US, but eventually gave up and bought a US power brick & cable from Apple, because the electrical buzzing through my hands and wrists from my MBP was very unnerving.

CalebCallisto

Not only can you buy cheap US cables, but traveling in the EU you can buy cheap european power cords and use the same power brick.

Eliot

Also, the ground does to do something. It keeps a normally crappy physical connection a little bit more securely attached to the wall.

My Kensington 2-prong falls out all the time. My Acer 3-prong, never.

lmathews

@brettt: Voltage roulette?

Voltage roulette? Oh wow.

Try unscrewing the PCB from an ATX power supply while it's on. Now THAT is voltage roulette.

lmathews

I'd just like to clear up a little bit of confusion that has cropped up. In an AC line there connections are live and neutral, not positive and negative. This is important because if you measure against ground, neutral should be at 0 volts, and live should carry the line voltage (which alternates between positive and negative 50 or 60 times a second, depending on system). Most AC devices don't care about which is which, but in fixed installations it does matter.

jsiren

@Freezen: re: "There are 3 connections into your wall - Positive, Negative, and Ground.There are 2 connections making it into your power brick: Positive, and Negative. Read that again: The ground is being dropped, ignored, not connected. It only existing where it plugs into the wall, it doesn't travel up the cables. "

Not true. The power supply has a metal knob (like the head of a nail), in addition to the two-wire power connector. The power cord has a cavity that mates with the nail-head and inside the cavity is some metal that contacts the nail head. And guess what: The metal in there is connected to the ground.

No idea why -- the whole thing is odd. But that's what's there.

(And in any case, all this is zero importance.)

moe52

@philosopher_dog:

Yeah, I dunno. The white grounded cable that plugs into this power brick might weigh a couple of ounces more than the pictured PlayStation cable.

There really isn't much weight savings and as moe52 and I pointed out before, it makes more sense using the two-prong ungrounded mini-plug and carrying a short, multi-outlet extension cord.

This "lifehack" makes absolutely zero sense.

Deprong Mori

This is confusing. It appears that he's just plugging a black PowerStation cable into the brick itself. How does this save weight? Don't you still have to carry that big white brick around with you?

Also, doesn't this ruin the Mac aesthetic? Some dusty old power cable plugging into your shiny white Mac?

If the Mac has a grounded plug and you're plugging it in with a non-grounded cable, then you're losing your ground. I would think that's not your best idea. Grounding electronics aren't just done for decoration. Many Macs only have 2 prong plugs, without a ground. I've always found that to be a bit risky, especially if you have it in your lap with beverages around. Think about it. It's common sense. Electricity takes the shortest route of least resistance. If there's a failure, it's likely to go through you then, since you might well be the ground. It's not rocket science. That would be a gross (and foolish) way to die.

philosopher_dog

The documentation that comes with a new Apple power adapter shows exactly this. It's completely safe, or assumedly show since Apple recommends it in their instructions.

tedyc03

@Bob Brown:

They charge a premium, but only for trolls.

Deprong Mori

So, like a lot of other stuff on a Mac, the third prong is nice, useful looking, but actually unnecessary.

I bet they charge a premium for that useless piece of metal.

Bob Brown

For anyone who's not reading and just looking at the article:
The ground on this does nothing.

There are 3 connections into your wall - Positive, Negative, and Ground.

There are 2 connections making it into your power brick: Positive, and Negative. Read that again: The ground is being dropped, ignored, not connected. It only existing where it plugs into the wall, it doesn't travel up the cables.

Freezen

Ground = Good

Rob S.

The end of the apple cable which plugs into the power brick does not have a ground prong. It only has the +ve and -ve.

That means that the ground prong on the end which goes into the wall is redundant, and doesn't go anywhere.

Replacing the cord with one which doesn't include a redundant prong will not give you any problems.

Munkii

By the way, what I do with my MacBook, is use the short power thingy and carry a lightweight extension cord with multiple taps (which is useful for other things as well). Lightweight and versatile.

Yeah, that's what I do. I think you can pick up a 3' or so cord with three outlets for a couple bucks at any hardware store. Plus, it functions with other items (e.g., cellphone chargers, battery chargers) whereas this PlayStation power cord has limited functionality.

Deprong Mori

Did someone call a EE?

Here's the deal. The fact that the small power mini-plug is two prong and ungrounded says that a ground connection is not electrically necessary. As for why the long-cord is grounded, I don't know. Might be a UL/CSA requirement or maybe Apple uses one part for multiple products.

Can you use a two-prong replacement instead of the three-wire one Apple provides. I would -- but will bet you will not see any official source say it's OK. It won't fry you or your computer or cause electrical noise.

There is a general question of why some gadgets require grounded cords and polarized plugs and some don't. Non-grounded gadgets have power supplies that are isolated -- there is no continuous electrical path between the power connectors (either of them) and the appliance. And the isolation (double isolation, actually) is tested and certified (that UL/CSA thing again).

Ground connections normally don't do anything or carry current. They are a safety net. If something comes loose and connects power to the gadget's chassis, the ground connector runs that voltage to the ground and causes a fuse to blow. Your device is dead but you're not. Good tradeoff.

By the way, what I do with my MacBook, is use the short power thingy and carry a lightweight extension cord with multiple taps (which is useful for other things as well). Lightweight and versatile.

moe52

@dreamlayers:

That's good and all, except that the ground isn't carried to the Mac brick. All that the line carries is the two connections, just the same as a standard figure-8.

SMSDHubbard

@TommySez: since when does black and white clash?

balls187++

I did this in Amsterdam for the US to Holland adaptor. Worked like a charm.

Gina Trapani

The ground appears to be connected to the lug that the end of the cord slides over. However, every power supply I've ever encountered work fine without the grounding pin. It's only there for safety if something goes wrong.

Also, I'd hardly classify this as a "hack". Maybe it's a hack in Mac circles... (I'm using a macbook pro right now, so don't bitch at me)

mattzog

Well, not necessarily everything after posting that, but most things certainly, and if that were the case all sockets would support the plug.

Onouris

Things are grounded for a reason...

I am surprised there's a country left in the world where grounding isn't on everything...

Onouris

@cbartlett:
So what about all the other laptops (such as my Toshiba) that don't have a grounded plug-in? Why am I not currently being electrocuted?

exp

The stock Apple two-prong adapter still has a ground doesn't it? Isn't that why it still has to slide onto the little metal grounding post?

Corrupted_Data

The mini-plug is unpolarized (like virtually all portable transformers), so there is no difference between using it and a standard (Playstation) power cord.

The real question is what tangible benefit is there to using the three prong plug over the mini-plug. As far as I know Apple doesn't provide any guidance on when to use one over the other.

astrosmash

You can buy "laptop power cords" at fry's for like 4 bucks. I leave them strategically placed around my house and carry my little MacBook brick around with me.

cebailey

Meh.

differentdog

[img148.imageshack.us]

@brettt:

erm the power cord is what transport power from the wall to the power supply, yes that white brick is a power supply equal to the internal noise box on pcs the thing is this power supply does not change from region to region so regardless of the power you feed it from whatever figure of 8 power cable you put in there your computer will not blow up (power fluctuations however are a different subject completely)

also see picture for reference

Gonzie

I've been doing this for years when visiting my parents in Ireland. The same cord comes with radios, DVD players, VCRs etc. so my dad has amassed an enormous collection of them over time. No problems so far.

johnmcorg

wtf?!?

it's a standard figure 8 power cable. Same as every other non-grounded electrical device. (stereo's, dvd players, ps2, ps1).

How is this a tip? You can use the any cable that matches the apple power supply?

Yes, the apple one has a nice looking attachment on the end that looks nice and shiny, and fits nicely in the power adapter, but any cable will work perfectly.

stepnet

@Deprong Mori: Because the author wants a longer cord than the mini plug, but doesn't want to deal with the bulky one Apple provided (which inexplicably has a third prong, even though it's apparently completely unnecessary). Did you not even read it?

HeartBurnKid

I've been doing this for years. no problems. FYI: There's only one advantage to using the 3 pronged cord over the two (including the supplied flip-out and this "hack")- if you're on a electrical line that is improperly wired, you may feel a buzz on the chassis of your powerbook (bc of the metal). Plug in using the grounded adapter, and this won't be a problem.

robogobo

Thanks for the tip. This works perfectly for my old powerbook g4, which doesn't have the third prong. I always hated that the giant inverter took up so many spaces. Now I don't have to complain about it anymore.

m-unit

Xirian's right. The mini-plug that comes with the brick has two prongs. Just use that.

I've owned Apple notebook computers since 2002 and they've all functioned fine with the two-prong ungrounded brick. I don't see the point (or debate) about this "tip."

Deprong Mori

I took this hack one step further when I found a cord in a misc. bin of power cables at a computer recycling store (RePC) in Seattle. Like the cord in this article, it fit perfectly into my MBP power adapter, and the other end had a EU-style power plug. I'm going to take that with me the next time I travel to Europe or India on business, instead of Apple's plug adapter kit). Then I can either leave my bulky universal travel plug adapter at home, or use it for other devices (cell phone charger, for example)...at the very least, I won't have to dig it out of my carry-on bag at the hotel or airport.

CyberDave

Electronics like the MacBook pro with metal cases are especially important to keep grounded. Because the ground is tied to the case. And if the ground doesn't have anywhere to go.. because it's not attached to the outlet... it goes through your hands.

Anyone with an EE degree want to chime in? I'm a drop out.

cbartlett

I'd rather not play voltage roulette and watch my computer explode.

brettt

@xirian: I think the point is to allow you a longer cord without dealing with the heft of Apple's cord.

I've never found the cord to be a problem, heft-wide. Plus, the Playstation cord wouldn't be white. I'm not sure I could handle the clash.

TommySez

Without a ground it's possible that a single failure could leave exposed parts at line voltage. Also, even without a failure, capacitive coupling and leakage can put quite a voltage on the laptop's ground, and that might be a problem when connecting peripherals. You can probably get away with it and it's very unlikely you'd get electrocuted (ie. die). Nevertheless, such advice shouldn't be found on a site like this.

dreamlayers

I used a similar trick on my Powerbook G4 in Europe when I ran out of power adapters. I simply found an old power cable for a boombox that fit. Looks scary, but worked like charm.

manuel.schroeder

I was going to complain that you would only have a 50/50 chance of it being properly grounded. But the stubby plug it replaces doesn't have a wider plug prong for grounding. That would suggest that the power supply doesn't care.

So, why is the longer cord three-pronged? Beats me. Electronics class was decades ago.

TommySez

or you can just use the mini plug that it comes with that lets you plug the brick directly into the wall.

xirian

I doubt you are causing any significant hazard, as the small piece with the flip out prongs does not have a third, ground, prong either.

FrankBurns