›      ›      |1050 DISK DRIVE POWER PACK|›      |>>>>>BY BRAD JAWORSKI<<<<<|›      
›      |DIAGRAM BY MATHEW BENNETT!|›      ››              ÉÎÔÒÏÄÕÃÔÉÏΛ›   The two main reasons for making this›power pack are:›1.The power pack will last much longer›   than the origional because it is air›   cooled.›2.It is easily repairable without great›  expense.›› A slight drawback is a slight hum that›the exposed transformer makes. This can›be  controlled further  if thin  rubber›bushings   are   used   between   the›transformer and the base. I did not use›the rubber bushings and now do not even›notice the hum.›› The   disk   drive   needs   9volts AC›(alternating current) applied to it for›power. This is done by using an 18 Volt›AC transformer  (easy to obtain) with a›CT (center-tap).  We use the center-tap›to  reduce the  voltage by one-half  to›get the needed 9volts AC.›› Do not worry that the 9volts AC is not›regulated  because  the  power  pack is›only stage one,  of several stages,  to›supply  power  to  the drive. The other›stages  are within the drive itself and›the  power is  transformed into a  well›regulated +5 volts DC and +12 volts DC.›(see power supply diagram)››              Éîóôòõãôéïîó›› 1) The first thing to do is to cut off› the  wires (two) from the base of  the› orginal old transformer. Make sure you› cut  the wires off near the  base. You› will need these wires for the project.›› 2) To start simply anchor the trans---› former  to the  floor  of the  cabinet› near the vent holes. (rivets or nuts--› and bolts)If you want less transformer› hum,  you  can  put  rubber  bushings› between the transformer and the floor.› (not need)›› 3) Drill holes  the required  size for› strain reliefs and the fuse holder.  3› holes in all. (hardest part of the pro› ject)›› 4) Mount the fuse holder (epoxy if----› necessary)  and the power and  supply› wires. Use the strain reliefs with the› wires to prevent short circuits.›› 5) Attach all wires inside the cabinet› with wire connectors (wire nuts) as in› the diagram.  Attach  the  120volt  AC› plug wires (two pronged) to one of the› 120volt  wires (black) on the  primary› side of the transformer and solder the› other  wire to one of the fuse  holder› terminals.›› 6) Next  connect the other 120volt  AC› transformer  wire  to the  other  fuse› holder terminal. (both transformer ---› wires on the primary 120volt side are-› black) It does not matter which trans-› former wires you use on the 120volt AC› side.›› 7) Next connect the  two wires that go› to the disk drive. The black wire with› the  white stripe  goes to one of  the› yellow wires(doesn't matter which one)› and the black goes to the black(center› tap)on the transformer 9volt secondary› side. (on the transformer, Yellow to--› Yellow will give you 18volts AC)Yellow› to Black (center-tap) will give you 9-› volts AC. Don't  forget to put a  wire› connector on the Yellow secondary wire› not being used.  This prevents it from› shorting out on the cabinet.›› 8)Install fuse and power pack is ready› to be used. One Amp Fuse is well below› the 2 Amp rating of the transformer.To› make a long story short, the trans----› former  is working  at less than  half› its capacity and as a result will last› a long time.›››ÎÏÔÅ: A switch may be added if desired.›     All my electronic hardware is on a›     Voltage Spike Protected AC Power›     Strip with one switch. It turns›     all powered items off and on›     making a switch unnecessary.››      Each disk drive requires 1 18volt›     AC transformer. Do  not  use  the›     other Yellow wire(the one not used›     ) to power another disk drive. It›     will not work.›››               ÐÁÒÔÓ ÌÉÓÔ›Radio Shack:› 1 273-1515   Transformer     $8.99›              18volt CT›› 1 270-1273      Fuses        $ .79›              Fast acting›› 1 270-251    Metal Cabinet   $5.99›                6x2 3/8x4›› 1 64-3026   wire Connectors  $1.29›               16 assorted›› 1 278-1636  Strain Reliefs   $ .69›                Set of 6›› 1 270-364    Fuse Holder     $1.29›              panel mount›              (long type)›                              -----›                      TOTAL = $19.04› --------------------------------------››                ÄÉÁÇÒÁÍ››          (VENTS ON SIDE CABINET)›         ›         |                       |›         |                       |›                           |› FUSE:||	
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   (BLACK) | |BLACK |›         |                |120V›         |            | PRI |    | --›TO: DISK |              | AC›


DRIVE |           | TRANS |   |›     |   |              |›      |            | SEC |    |›   ||   (YELLOW)     |› |
 | | (Y) |› |
 < |›      |   (BLACK)    WIRE   | |›  9V-AC  |           CONNECTOR |›         › --------------------------------------›››