[sdiy] Hooking up a Power-One unit

[Cynthia Webster]

The Extra Narrow faston crimp connectors that fit those transformer pins 
are somewhat difficult to find,
and you must form "Y" connections with these anyway  which is rather 
fiddly, so I recommend skipping
those and soldering directly to the pins.
With high voltage especially make sure that the connections you make are 
physically sound without
any solder - before you solder them, in other words, if there was a 
meltdown and all the solder went
liquid, would the connections hold anyway?  (that is the ideal to strive 
for).

There are five Transformer pins as you will see in the diagram that came 
with the supply...
Two pairs get linked or wired together and the fifth pin gets cut short 
to keep it out of the way.

Bus wire is used to link these pins into pairs and after they get 
soldered there is really no way to get heat
shrink tubing over the resulting connections, so after the dust settles 
and all the soldering is done to
the transformer pins, then I recommend laying up several layers of epoxy 
over the soldered transformer
pins as a way of insulating them.    Be absolutely certain that the 
epoxy that you choose is totally inert
and does not contain iron filings or aluminum powder such as JB Weld (Do 
not use this one!)
Pick an epoxy that is beige colored or whitish in color not gray, black, 
or silverish in color...
I do a first coat of the pins an let them dry, and then do a second coat 
the next day and build a little
cardboard dam around the pins and then fill the little cardboard boxed 
area around the pins until they're
completely covered.  In the morning you can rip off the cardboard and 
have a lovely block of epoxy over
those transformer pins and never fear electrocution :) 

If you do not have any 22 or 20 gauge bus wire handy then start 
auditioning paper clips around the house
for their suitability.

You can also use a tube of Marine GOOP over the pins, but the resulting 
dried glump of goop is
not completely fireproof so it might insulate, but if it catches... then 
it also provides fuel for an internal
fire.  It took a couple of years for me to sort this out and I've found 
epoxy to be the best.

Remember, all this epoxy talk is only for the 117Volt AC coming of the 
mains, of course the low voltage
DC Output connections do not need any of this extra insulation.  I use 
14 gauge Gausti brand
"600 Volt" wire from Marvac.com, (ask for Mike and tell him I sent ya').
If you have no idea what colors to use, you can follow the Modcan 
convention of
(RED= +15), (Green=0 Volts or "Ground"), and (White=Minus 15V)

The green Ground wire of the mains cable gets bolted directly to the 
frame of the power supply, and
can be done with a fast on loop connector and a 8-32 screw, lockwasher, 
and 8-32 nut for example.
You may even see a little ground symbol in the middle area of the frame 
with a hole next to it for
this  #8 or #10 grounding screw.

The Power Supply Chassis Ground connected to the the center pin of the 
117VAC electrical cord
should only connect to the power supply... and Not connect to anywhere 
else in the synth.
"System level audio/control voltage Ground" is 0 Volts or the center pin 
of the outputs of your new
supply, and this ground has nothing to do with the ground pin on the 
117VAC electrical cord.
Keep the grounds separate.  I recommend adding a black or green banana 
plug to the front panel
somewhere on your system so as to make System ground available whenever 
you want to interface
with another brand or format of synth...   You can add some LEDs to 
monitor power...

The feedback pins on the outputs are only for long cable runs between 
synth and power supply
so just ignore them.

Here are some more Frequently asked questions about power supplies

http://www.cyndustries.com/modules_powerdist-FAQ.cfm

http://www.cyndustries.com/modules_POWSU_2.cfm

Good Luck with your project!

Cynthia