#011: Magnetic Power Adapters
Apple MacBook laptops feature a magnetic power adapter called ‘MagSafe’. The power cord is held in place magnetically, so if someone should trip over it, the cable disconnects harmlessly and the Mac stays put.
It’s a nifty invention that saves on repair costs and prevents that gut-wrenching feeling of seeing your laptop dragged across the unforgiving floor. Thanks, magnets!
#004: Hard Drives & Data Storage
Chances are you’re reading this post on a computer, in which case it’s highly likely that there are magnets ticking away to help bring you this very post. Where? They’re hiding in your hard drive.
Just like tape recorders of the day, computer hard drives record and access data using a form of magnetic data storage. At the heart of your hard drive is a ferromagnetic platter that holds a magnetic recording material. When you save a document, your computer converts it into thousands of 1’s and 0’s (bytes) which your hard drive then records to the magnetic platter as a north or a south pole. When it comes time to open the document, the hard drive reads 1’s and 0’s back to the computer and the processor assembles them into your document.
It’s an easy concept that is much, much harder in execution, mostly due to the impossibly small nature of computer parts. A 100 gigabyte hard drive (probably below average these days) has the capacity to store 107,374,182,400 bytes (107.3 trillion). That’s a lot of 1’s and 0’s, and it means a lot of work for the magnetic head of a hard drive!
But of course, there’s more than just one magnet at work inside a hard drive. The electric motor (#003) that spins the hard drive uses magnets, as does the ‘voice coil’ type actuator that moves the head to read the data. Two high-grade Rare Earth (Neodymium-Iron-Boron) magnets are used to control the position of the head with ultimate precision.
It gets complicated, so if you want to learn more you can read about it at Wikipedia or HowStuffWorks. You can also watch this video to see the inside of a hard drive working away. Go, magnets, go!
