[sdiy] Hooking up a Power-One unit

[David G. Dixon]

Thanks, Cynthia!  I have epoxy in my lab for mounting scanning-electron
microscope specimens, and this will work perfectly.

One question: If the AC mains ground is bolted to the power supply chassis,
and the power supply chassis is bolted to a panel which is bolted to the
synth case frame, then how does this ground not interact with the rest of
the synth?  I have definitely seen, for example, MOTM systems (in pictures,
mind) with the power supply module sharing space with the other modules on
the front panel.  I have to assume that the entire front panel is common in
that case, including the power supply chassis.  (If this is strictly not
true, perhaps someone with an MOTM system can disabuse me of this notion.)


> -----Original Message-----
> From: Cynthia Webster [mailto:cynthia.webster at gte.net]
> Sent: Monday, April 06, 2009 9:11 AM
> To: John Luciani
> Cc: David G. Dixon; synth diy
> Subject: Re: [sdiy] Hooking up a Power-One unit
> 
> 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 love 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...
> 
> 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
> 
> http://www.cyndustries.com/
> 
> 
> 
> John Luciani wrote:
> > On Sun, Apr 5, 2009 at 6:15 PM, David G. Dixon
> <dixon at interchange.ubc.ca> wrote:
> >
> >> Another noobie crisis:
> >>
> >> Looking at my new Power-One +/-15V, 1.5A power supply, I have two
> questions:
> >>
> >> 1.  Do you solder 120VAC leads to the flat terminals sticking out of
> the
> >> transformer, or do you slide something onto them without soldering?  Is
> it a
> >> good idea to put shrink tubing on them afterwards?
> >>
> >
> > The flat tabs are mostly likely Fast-on terminals. You want to get the
> insulated
> > crimp terminals and then a small crimp tool like an AMP Champ. There are
> three
> > popular sizes for different gauge wires -- 18-22 (red), 14-18 (blue),
> > 10-12 (yellow).
> > The red ones should be fine for your application.
> >
> > I do not use heatshrink or tape.
> >
> >
> >> 2.  Is there some special doodad that slides onto those funny looking
> DC
> >> terminals sticking out of the edge of the PC board, or do you just wrap
> wire
> >> around them and solder?
> >>
> >
> > What do the doodad's look like?
> >
> >
> >> (I know: pathetic!  But I want to get this part right, and this thing
> comes
> >> with virtually no instructions.)
> >>
> >
> > IIRC Power One stuff if typically OEM. There are probably instructions
> > on the website. You may also want to see if they sell accessories. Even
> if
> > you don't buy the accessories you can get an idea about how things
> > connect.
> >
> > (* jcl *)
> >
> >
> >