[sdiy] That old modular power supply question (again)

[m.bareille at free.fr]

>>  The tip is to correctly drain
> > all ground lines and to wire them like a 'star' with large gauge wires or
> > to twice all ground wires like on a PC psu...
>
> Unless panel ground is wired separately, star ground is defeated as soon as
> a patch cord is connected between two modules, or if the modules are bolted
> to a common metal frame.  However, it doesn't seem to make much difference.


There is one exception to this : if your modular use banana patch cords only :)
Into my modular most of logic signals ( gates, triggers ) are with bananas plugs
but not the audio /Cvs pathes.

The important 'detail' is to wire all PSU boards ground point togheter with a
large drain, so you do not have to rely on the front panel grounds who sometimes
can be not as good as expected for multiples reasons...



> > Another advantage of multiple small PSUs is that you can have 100%
> > independant cabinets. A central big PSU can be a good solution too, but
> > this is more expensive usually and the regulator section will be much more
> > complex. You can take example of large mixing desk PSU. You will also need
> > to evaluate the total power and size your big PSU accordingly.
>
> It depends on how big your cabinets are.  Mine are small, and only
> accommodate 5-8 modules each.  I have a 15V Power-One which puts out 1.5A
> max on each rail, and should therefore be able to power four or five such
> cabinets with no problems.  My modular is "designed" to be somewhat mobile,
> and it will be nice not to have to plug each little cabinet into the wall.
>

One of my cabinet is  a 18 x MOTM style 2U panels. There is 2 PSU inside each
with a 100VA transformer and i distribute the 220V line inside the box , so
there is only one main plug on the rear panel and one power switche on the
panel.

An intermediate solution is a big transformer in the middle to feed many small
PSU boards of 1A or 1.5 A each ...  That's the way i have wired my second
cabinet for the moment .



Marc B.