is a proprietary magnet
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, and attracts or repels other magnets.A permanent magnet is an object...
ically-attached power connector introduced by Apple Inc. on January 10, 2006 in conjunction with the MacBook Pro
The MacBook Pro is a line of Macintosh portable computers introduced in January 2006 by Apple. It replaced the PowerBook G4 and was the second model, after the iMac, to be announced in the Apple–Intel transition...
at the Macworld Expo in San Francisco. The MagSafe connector is held in place by a magnet so that if it is tugged on, for example by someone tripping over the cord, it will pull out of the socket safely, without damaging the connector or the computer power socket, or pulling the computer off of a table or desk. MagSafe is similar to the magnetic power connectors that many deep fryers and Japanese countertop cooking appliances have in order to avoid spilling their dangerously hot contents. Apple exclusively owns ("Magnetic connector for electronic device", issued in 2007) and does not license the MagSafe connector or the patent.
MagSafe has connector pins that are designed so the rectangular connector can be inserted in either orientation (however the newer version of the connector can only be fitted in one orientation without blocking neighboring ports, such as USB). LED
LEd is a TeX/LaTeX editing software working under Microsoft Windows. It is a freeware product....
s on both sides show green
Green is a color, the perception of which is evoked by light having a spectrum dominated by energy with a wavelength of roughly 520–570 nanometres. In the subtractive color system, it is not a primary color, but is created out of a mixture of yellow and blue, or yellow and cyan; it is considered...
if the computer battery is fully charged and amber
Amber is an orange-yellow color that got its name from the material known as amber. Due to this, amber can refer not to one but to a series of shades of orange, since the natural material varies from nearly yellow when newer to orange or reddish-orange when older.-Amber:Amber is a pure chroma color...
Red is any of a number of similar colors evoked by light consisting predominantly of the longest wavelengths of light discernible by the human eye, in the wavelength range of roughly 630–740 nm. Longer wavelengths than this are called infrared , and cannot be seen by the naked eye...
if the battery is charging. MagSafe can be found on the MacBook
The MacBook was a brand of Macintosh notebook computers built by Apple Inc. First introduced in May 2006, it replaced the iBook and 12-inch PowerBook series of notebooks as a part of the Apple–Intel transition. Positioned as the low end of the MacBook family, the Apple MacBook was aimed at the...
, MacBook Pro, and MacBook Air
The MacBook Air family is a line of Apple ultraportable Macintosh notebook computers.The first-generation MacBook Air was a 13.3"-only model, previously promoted as the World's Thinnest Notebook, introduced at the Macworld Conference & Expo on January 15, 2008. It featured a custom Intel Merom CPU...
notebook computers, as well as the Apple LED Cinema Display.
The MacBook and the 13" MacBook Pro use a 60 W MagSafe charger, whereas the 15" and 17" MacBook Pro use a 85 W MagSafe charger. Although the 60 W and 85 W MagSafe connectors are identical in appearance, Apple recommends using only the adapter that was provided with the machine. The MacBook Air has a different sized, lower powered 45 W version of the MagSafe adapter. The power brick is smaller, but the MagSafe connector is the same size.
Apple also offers a MagSafe Airline Adapter
for use on certain compatible airplanes. It has a DC input (instead of AC like the original MagSafe chargers) and will power the computer, but will not charge the battery.
The MagSafe connector pins are palindromic
A palindrome is a word, phrase, number, or other sequence of units that can be read the same way in either direction, with general allowances for adjustments to punctuation and word dividers....
, allowing for the adapter to be inserted in two opposite orientations. The first and second pins on each side of the tiny central pin have continuity with their mirror pins.
- The inner large pins are V+ (16.5 VDC). Measuring with no load will give 6.86 VDC; the full 16.5 V is provided to the proper load.
- The outer large pins are Ground.
- The tiny center pin is a Charge Control pin that assists with changing the LED color, and also assists with switching the adapter off. No power will be outputted from any of the other ports until contact is made with the center Charge Control pin. This PIN is also used to transfer additional Information like the powertype and serialnumber of the powersupply.
The rectangular metal shroud surrounding the pins has no electrical function. Rather it acts as shielding
Electromagnetic shielding is the process of reducing the electromagnetic field in a space by blocking the field with barriers made of conductive and/or magnetic materials. Shielding is typically applied to enclosures to isolate electrical devices from the 'outside world' and to cables to isolate...
for the electrical pins and a ferrous attractor for the magnet in the laptop.
Criticisms and defects
Although Apple does not license the MagSafe connector for use in third-party products, manufacturers have devised a workaround: their MagSafe items use the actual connector from Apple’s AC adapter, grafted onto their own product. Since this uses an actual Apple product, purchased legally, manufacturers believe that no licensing agreements are needed and the patents are not violated. However, in 2010 Apple still sued one such manufacturer, Sanho Corporation, for selling its very popular HyperMac battery extension products which Apple claimed violated their patents, resulting in Sanho ceasing to sell their connector cable for the Hypermac series of external batteries.
Many users have reported (as of October 30, 2011) problems with the quality of the construction of the MagSafe cords, giving the product low marks on the Apple Store’s website
The Apple Store is the online store of Apple Inc.. All of Apple's product lines are carried as well as select brands of accessories for its products. It is owned and operated by Apple in Cupertino, California...
. Common complaints include plug separating from the cord, transformer shorting, and pin springs losing elasticity.
Several methods have been devised to protect the MagSafe from failure, including wrapping the cable with tape or sliding protective plastic around the cable.
In 2008, Apple posted an official response acknowledging problems with MagSafe adapters, which include incomplete circuit connection and adapter's white insulation separating from the magnetic end of the MagSafe connector. Following the release of a Knowledge Base article, a class action lawsuit was filed on 2009-05-01 in the California Northern District Court's San Jose office, alleging that the MagSafe power adapter is prone to frayed wires and overheating, and as such represents a fire hazard. Apple has since released a new connector to remedy the defects.
There had been a variety of reports of the newer MagSafe AC adapter not working with older MagSafe-powered MacBooks and MacBook Pros. Apple released a firmware update in October 2010 that it claims resolves this issue. However the installer for the firmware update will not run on certain older MacBooks, which means that the firmware can not be updated. This in turn means that it is not possible to use the new MagSafe power adapter with these MacBooks. Currently it is not possible to buy new replacement MagSafe AC adapters (either from Apple or third-party suppliers) that work with these MacBooks, forcing owners to look for used original adapters.
In 2011, Apple posted a support document regarding the strain relief problems with the MPM-1 ("T") style MagSafe power cables, and issued settlement offer for buyers of Apple 60W or 85W MagSafe MPM-1 adapter within the first 3 years of purchase.
Prior power systems
| Close-up view of the brick plug on the left, and the puck plug on the right, with tip ring sleeve plugs and a metal ring around the plug. The puck charger simply had a dark gray shroud, while the brick added the clear plastic charge indicator ring.
Prior to the development of MagSafe, early Apple laptop computers such as the PowerBook series used a shell and socket/pin arrangement (coaxial power connector
A coaxial power connector is a miniature power connector used for attaching extra-low voltage devices such as consumer electronics to external electricity...
) similar to those seen on non-Apple laptops. The iBook series introduced a new plug design similar in appearance to a mini-stereo plug, but with an additional metal ring around the plug. The first puck-shaped iBook chargers simply had a silver plug body, but the square white chargers introduced a color-changing illuminated ring that indicated charging status.
Tripping on an iBook cord or yanking the cord out at an angle frequently damaged the power socket by breaking the solder pads
Surface mount technology is a method for constructing electronic circuits in which the components are mounted directly onto the surface of printed circuit boards . An electronic device so made is called a surface mount device...
under the connector, resulting in a laptop that would fail to charge when connected to the cord, or would only charge if the inserted plug were propped up or pushed down at an angle. The spring contacts inside the socket connector could also become bent out of position due to angular pressure on the plug, resulting in intermittent charging problems. In such situations, the illuminated power plug functioned in an unusual manner which is undocumented. The earlier, puck-shaped iBook chargers would also fail to charge if the socket were damaged, but those chargers could not indicate a problem.
In severe cable-stress situations, the outer flange of the plug became flared and bent, and the tip of the power plug could break off and become lodged inside the socket.
Due to the design of the early 12 inch G3 iBooks, replacing the damaged "DC-In Board" typically involved a complex, 50-step laptop disassembly process, resulting in an expensive, labor-intensive repair.
The development of MagSafe reduced the cable strain problems, and eliminated most power connector damage and repair costs for Apple laptop owners.