Exidy Sorcerer

From: Louis Schulman <louiss_at_gate.net>
Date: Thu May 17 19:02:54 2001

On Thu, 17 May 2001 21:50:36 +0100 (BST), Tony Duell wrote:

#>
#> On May 16, 21:59, Louis Schulman wrote:
#>
#> > Well, I just got a fabled but seldom seen Exidy Sorcerer. It has
a
#> > power supply problem (including the need to be converted back from
220
#> > to 110V) but I am working on that.
#>
#> That should be fairly easy; you just change the transformer
connections
#> inside the case. The 110V setting has two primary windings
connected in
#> parallel to the mains; for 240V the black/red and black/yellow wire
would
#> have been cut at the mains filter and joined together, putting the
two
#> windings in series.
#
#
#Pete will know this, but a word of warning for anyone else trying
that.
#It's _essential_ that you have the 2 windings the right way round ('in

#phase'), otherwise you are effectively shorting out the output of a
#110V-220V autotransformer when you make the second connection. Which
will
#result in a blown fuse at best and a ruined transformer at worst.
#
#The safest way to do it (even if you have a manual showing the right
#connections) is to do the following:
#
#1) Disconnect the secondary winding leads from the computer (you want
no
#load on the transformer)
#
#2) Cut the joint between the 2 primary windings (the bk/r and bk/y
wires
#that Pete mentioned), leaving the other primary winding wires in
place.
#These will be connected to the mains switch/filter in general.
#
#3) Check for continuity between the 2 cut ends and the other 2 primary

#(black/something) wires, which will be connected to the
switch/filter/etc.
#
#4) Connect one of the 'cut' wires to the transformer primary wire at
the
#switch/filter/etc that it _doesn't_ show any continuity to. By doing
that
#you've connected one of the 110V primary windings across the mains.
#
#5) Insulate the other cut end for the moment (it is connected to the
live
#mains side of the PSU after all). Connect an AC voltmeter to a
secondary
#winding. Switch on and check that you get something on the meter.
Switch
#off and unplug
#
#6) Connect an AC voltmeter, good to 220V at least, between the
remaining
#'cut end' and the other primary wire at the output of the
#switch/filter/etc. Switch on again. You should get essentially 0V on
the
#meter. If you get 220V, then you've got a winding connected backwards
#(how you could do this following the above steps is a mystery, but
it's
#better to be safe).
#
#7) Assuming it's OK, unplug it again, remove the meter, and connect
the
#remaining uncut end to the tag (i.e. effectively short out the meter).

#Test the output voltage again o nthe secondary windings, and if it all

#looks OK, reconnect the secondary to the PCB, etc.
#
#
#Some schematics to help understand the above :
#
#220V wiring : 2 primary windings in series :
#
#
# L-----------------------)||
# )||
# )||
# )||(---------------
# )||(
# +------)||(
# | ||( Secondary winding output
# | ||(
# +------)||(
# )||(
# )||(----------------
# )||
# )||
# N----------------------)||
#
#
#First test : One primary across 120V mains, other not used :
#
# L-------------+---------)||
# | )||
# | )||
# | )||(---------------
# | )||(
# | +----)||(
# | ||( Secondary winding output
# | ||(
# +---------)||(
# )||(
# )||(----------------
# )||
# )||
# N----------------------)||
#
#
#
#Check secondary output voltage on no-load just to make sure it's doing

#something.
#
#
#Second test : Check primary phase is correct using voltmeter :
#
#
# L-------------+---------)||
# | )||
# | )||
# | )||(---------------
# | )||(
# | +----)||(
# | | ||( Secondary winding output
# | | ||(
# +----)----)||(
# | )||(
# | )||(----------------
# (V) )||
# | )||
# N-----------------+----)||
#
#
#Voltmeter should read close to 0V in that circuit. If not, reverse
#connections to _one_ primary winding.
#
#
#FInal wiring for 110V mains : both primaries in parallel :
#
#
# L-------------+---------)||
# | )||
# | )||
# | )||(---------------
# | )||(
# | +----)||(
# | | ||( Secondary winding output
# | | ||(
# +----)----)||(
# | )||(
# | )||(----------------
# | )||
# | )||
# N-----------------+----)||
#
#
#
#-tony
#
Thanks Tony,

Very helpful. I had already figured this out (and had used a voltmeter
for continuity testing before hooking everything back up. In any
event, on my Sorecerer, the wires are different colors! And the colors
don't go where you would guess they go. Lesson: Don't depend on the
colors!

Louis
Received on Thu May 17 2001 - 19:02:54 BST