The MagSafe connector is a power connector introduced in conjunction with the MacBook Pro at the Macworld Expo in San Francisco on January 10, 2006. The MagSafe connector is held in place magnetically. As a result, if it is tugged on—for instance, by someone tripping over the cord—it comes out of the socket safely, without damaging it or the computer or pulling the computer off its 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.
Features
The MagSafe connector pins are designed so that the rectangular connector can be inserted in either orientation. LEDs on both sides show green if the computer batteries are fully charged and amber if they are charging. MagSafe can be found on MacBook Pro, MacBook and MacBook Air notebook computers.
Though the 60 W MacBook and 85 W MacBook Pro MagSafe connectors are identical, Apple recommends using only the adapter provided with the machine. The MacBook Air has a smaller 45 W version of the MagSafe adapter.
Apple's MagSafe Airline Adapter is available for DC hookups on certain airplanes.
Pinout
The MagSafe connector pins are palindromic. The first and second pin on each side of the tiny central pin has continuity with its mirror pin.
The inner large pin is 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 pin is ground
The tiny center pin appears to be charge control pin to change LED color and possibly adapter switch off
The rectangular metal shroud has no electrical function. Its purpose is solely for shielding the electrical pins and acting as a ferrous attractor for the magnets within the laptop's power receptacle.
Criticisms and defects
Apple has not licensed third-party products using MagSafe, however 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, no licensing agreements are violated.
Some users keep reporting (as of April 16 2008) problems with the quality of the construction of the MagSafe cords, giving the product low marks on the Apple Store’s website. Common complaints include plug separating from the cord (fraying), transformer shorting, and pin springs losing elasticity.
没有评论:
发表评论