Apple usb chanrge for mac air

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Rod doesn't get a lot of credit for this in the history books but he should. 'That switching power supply was as revolutionary as the Apple II logic board was. The introduction of a single-chip power supply controller in 1976 made switching power supplies simpler, smaller, and cheaper.Īpple's involvement with switching power supplies goes back to 1977 when Apple's chief engineer Rod Holt designed a switching power supply for the Apple II. In the 1950s, switching power supplies were complex and expensive, used in aerospace and satellite applications that needed small, lightweight power supplies.īy the early 1970s, new high-voltage transistors and other technology improvements made switching power supplies much cheaper and they became widely

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Switching power supplies are now very cheap, but this wasn't always the case. The switching power supply gets its name because it switches power on and off thousands of times a second, which turns out to be a very efficient way to do this conversion. Most consumer electronics, from your cell phone to your television, use a switching power supply to convert AC power from the wall to the low-voltage DC used by electronic circuits. Many electronic components work together to provide smooth power to your laptop.