home *** CD-ROM | disk | FTP | other *** search
/ ARM Club 3 / TheARMClub_PDCD3.iso / hensa / documentation / documents / a252fan < prev    next >
Internet Message Format  |  1999-04-27  |  2KB
  1. From: devos@eba.eb.ele.tue.nl (Gert Jan de Vos)
  2. Newsgroups: comp.sys.acorn.tech
  3. Subject: Re: IDEDisc4 DEADDEAD: Alive!
  4. Date: 29 Nov 1993 14:47:34 +0100
  5.  
  6.  
  7. Thanks to everyone who replied, I reconnected the drive with a friend's
  8. datacable and now it works fine, even though my own cable seems to be fine
  9. when checked with a multi-meter. The fan regulator is working fine
  10. too, here is a schematic of this simple but effective regulator:
  11.  
  12.     +-----//-----+-------+-------+---o +12V
  13.     |            |       |       |
  14.     \            |       \       |
  15.     / 10k        |       /       |         T1: Any NPN will do, eg: BC550
  16.     \ NTC        |   820 \       |         T2: PNP which can go up to 2A,
  17.     /      330uF |+      /       |             eg: BD238
  18.     \      16V  ===      \    | '-
  19.     |            |       +----|<  T2       Use P1 to select a default
  20.     |            |    | /     | \          fan speed such that the fan
  21.     +-----//-----+----|<  T1     |         will always keep running.
  22.                  |    | -'       |
  23.                  |       |  10k  |
  24.                  |       +-/\/\/-+---o Fan+
  25.                  |       |   |P1 |
  26.                  \       \   +---+
  27.                  /       /       |
  28.               2k \   270 \      ---
  29.                  /       /      / \
  30.                  \       \       | 
  31.                  |       |       | 
  32.                  +-------+-------+---o GND
  33.  
  34. Gert-Jan
  35. --
  36. Gert-Jan de Vos             devos@eb.ele.tue.nl | No matter what problem,
  37. Dpt. of Electrical Engineering                  | there's always a solution
  38. Digital Information Systems Group               | which is simple,elegant
  39. Room EH11.26 Eindhoven University of Technology | and wrong...
  40.  
  41.  
  42.