Re: power supply for Apple IIC

[dempson@swell.actrix.gen.nz (David Empson)]

In article <kb39359@pro-nsdapple.cts.com> tomk@pro-nsdapple.cts.com (Tom Kelly) writes:
> In <53269@db.GBA.NYU.EDU>
> sbhattac@db.GBA.NYU.EDU (Shankar Bhattacharyya) writes:
> >I need a replacement power supply for an Apple IIC. Since I am quite Apple
> >ignorant, I would appreciate any pointers as to where I might be able to
> >get one.
> >Alternatively, any advice as to how to take the power supply apart without
> >destroying it might also be helpful.
> >Thanks for any help you can give me.
> >- Shankar
> 
> 
> Which part is bad the external "brick" or the internal part of the power
> supply.  I believe that the 'brick" is just a RAW 13vdc supply.

According to the IIc reference manual, it provides 15VDC output, at
1.2A.  If you are going to replace the brick with your own supply, use
one with a slightly higher current output, if possible.

The internal power converter can be run from a DC supply which
provides between 9V and 20V.  If you use a lower voltage, you'll need
to supply more current (and vice versa).  The converter is rated at 25W
maximum.

I have heard that the IIc can be run from a car battery (or the
cigarette lighter socket).  I don't think a battery charger would be a
good idea - it probably switches the current on and off, and may use a
much higher voltage.


The internal power converter outputs power to the IIc as follows:

+5V at 1.2A
+12V at 0.6A continuous, 0.9A intermittent, and 1.5A surge for less
than 100 ms.
-12V at 100 mA
-5V at 50 mA  (not used in the IIc)


The external power connector is a 7-pin male DIN socket.  The pins are:

    notch
  7       1

6           2

  5       3
      4

1 and 7 are not connected.
2 and 3 are signal ground.
4 is shield ground.
5 and 6 are power input.


The internal power connector is apparently a 44 pin header.  The odd
numbered pins (along one side) are all ground.  The even numbered pins
are as follows:

2, 4      Ground
6, 8      -12V
10        No connection
12        External power input, via the switch on the IIc
14-22     +12FIN (whatever that means; possibly +12VIN input voltage)
24, 26    Ground
28-34     +5V
36-40     +12V
42, 44    Ground
-- 
David Empson                                                               
dempson@swell.actrix.gen.nz                                                
Snail mail: P.O. Box 27-103, Wellington, New Zealand