[sdiy] New modular & PowerOne units

[Jim Patchell]

    You could use a switcher, but, they do have their problems.  Being
nice and lite is their main advantage (lots of power in a small space),
generating noise is their bad point.

    Linear power supplies will give you fewer headaches, and if this is
your first excursion into DIY, you need a minimum of headaches, you will
have plenty of them (I am an old veteran at this, I still run into
problems that cause me headaches).

    1.5 Amps sounds like a good size.

    Now back to switchers and noise:

    One of the things I "salvaged" out of the dumpster recently was a
Guzik Read Write analyzer for testing hard disk heads.  To my suprise,
the thing had a switcher in it.  This thing is used to measure signals
that are very low level, so power supply noise is a no-no.  However,
when you look at the power supply, they went through quite a few
contortions to get rid of the noise from the supply.  After all of the
huge chokes and whatnot were added, the thing is about as big and heavy
as the equivelent linear supply, however, it does run a lot cooler than
a linear could.  So, it is posible to get rid of the noise, but it is a
lot of work.

    -Jim

sandrotraversi wrote:

> Hi all, I'm planning to build my first modular pulling modules both
> from efm, oakley, formant schematics ... As first step I have to buy a
> PSU. I'm looking at Power One units and I've found the HBB15-1.5A
> model , it's a linear unit offering +/-12v or +/-15v on about 1.5A.
> How good is the linear choice ? Why not a switching ?
>
>  Will that model suit well my needs ? Any comments are very welcome.
> Sandro