PeterH wrote: > > On Oct 23, 2008, at 3:09 PM, Bruce Johnson wrote: > >> Next time you get a dead HDD, tear it down. Good info on how drives >> are made nowadays,and you get two of the strongest damn refrigerator >> magnets you'll ever need. I have a hdd magnet on my fridge holding up >> about 15 pages of recipes. > > They are the strongest because it reduces the amount of current which > is required to power the "motor".
More importantly with stronger magnets they can get very high torque out of the head positioner and therefore shorter seek times. Making the head assembly as light as possible helps too. This particularly applies to the ends of the arms and the heads themselves. > > In my former employer's mainframe hard disk drives (3375, 3380 and > 3390 type) we also used 48volts dc instead of the customary 208-240 > volts three-phase ac for the spindle motor. > > When we would decommission a returned drive, the voice-coil "motor" > magnets were generally salvaged as these were the most powerful > permanent magnets then available. > > These often turned up as surplus items in many of the "usual > suspects" surplus electronics shops in Silicon Valley (Haltek, > Halted, Weird Stuff, etcetera). FYI, Haltek is long gone, the other two are still around. -- Clark Martin Redwood City, CA, USA Macintosh / Internet Consulting "I'm a designated driver on the Information Super Highway" --~--~---------~--~----~------------~-------~--~----~ You received this message because you are subscribed Low End Mac's G3-5 List, a group for those using G3, G4, and G5 desktop Macs - with a particular focus on Power Macs. The list FAQ is at http://lowendmac.com/lists/g-list.shtml and our netiquette guide is at http://www.lowendmac.com/lists/netiquette.shtml To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] For more options, visit this group at http://groups.google.com/group/g3-5-list?hl=en Low End Mac RSS feed at feed://lowendmac.com/feed.xml -~----------~----~----~----~------~----~------~--~---
