AC adapter for MacBook, MacBook Pro, and MacBook Air

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What is the 60W MagSafe output voltage?

What is the 60W MagSafe output voltage when it is disconnected from the computer?

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pamgb1963, the inner large pins are V+ (14.5 / 16.5 / 18.5 / 20 V DC). Measuring with no load will give 6.86 V DC for MagSafe and about 3 V DC for MagSafe 2; the full voltage is provided after a ~40kOhm load is applied for one second

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One of my guys wired up the DC board with a few comparators and LED's to emulate the load and offer a simple go - no go function.

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While not easy to see you'll find the side that is opposite the plug pins (where you grab it) in light gray print the specs of the unit. It should be marked 18.5 Volts.

You may find this helpful: Teardown and exploration of Apple's Magsafe connector.

Given the pin sizes I don't recommend trying to use a meter probe as you are more likely going to short it out. I have a spare DC In-board which I wired up with test leads when I need to check a power adapter.

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Dan, what is "alternating DC"?

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It's not a true constant DC voltage. Basically, it's rectified to DC but the capacitors are not quite able to smooth out the AC fully. If you have a scope it will have a slight sawtooth. I probably shouldn't have brought it into the dialog - Sorry.

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Thats my inner world digital head getting in the way of the outer world analog world we are discussing here ;-} Getting punchy for all of the snow I've been shoveling here in Boston. I think before the end of the month we'll wipeout every possible record from total snow per a season, to the largest amount on the ground and the fastest collection in a month. Let alone a single snow storm record! I wish I could share it to some of you folks that need it more than we do.

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AHa, you must be talking about the ripple which is common in DC voltage due to the incomplete suppression of the alternating waveform within the power supply. Poor choice of caps is a possibility. Cool to check it on an oscilloscope.....How is it going in your City? You guys ok with all the snow?

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I've had to go out 5 times today to dig out my walk and car. No sooner do I get it done the wind blows it all back ;-{ We now have over 4~5 feet of snow collected on the ground and the winds cut to your core.

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