In as far as converting 115 volts AC (line voltage) to 110 volts DC,
it is a piece of cake. The old 5 tube table radios of the 50's did this
as a matter of course. All that is really needed is a box to mount the
pieces in which should protect the parts from prying hands. That
voltage can kill under the right circumstances! A wooden box would
serve very nicely. You need a 25 Amp 150 Volt bridge rectifier or 4
25 amp 150 volt diodes. the voltage and amperage ratings can be higher
which will cause the diodes to run cooler and thus last longer
(hopefully). You the need a couple of 200 to 400 MFD capacitors and
perhaps a 20-40 henry choke. The choke might be unnecessary, but it
will reduce the noise in the DC voltage and certainly won't hurt. The
last item is a "bleeder resistor to discharge the capacitors when the
power is off. About 2000 ohms with a ten watt rating should do nicely.
This will provide a clean 110 volts DC and has but one problem, which
is the fact that it is transformerless, which means that it should be
given the same consideration as a wall outlet when it comes to shock
hazard. A 20 Amp isolation transformer would be preferred, but it is
rather expensive and probably weighs in the 20 to 30 pound category.
If any of the connections are where they can be accessed by anyone
then the transformer would be mandatory. The table radios got by using
an insulated case. If you have a problem getting something, I suppose
you could twist my arm and I would build something which would work ok
for just the cost of parts. I have been a radio tech and electronics
hobbyist for many years, so this is easy.

Contact me at jaimicook@ez-acces.com

 [ I'm a big fan of isolation transformers.  Without an isolation
 [ transformer if you want ANY of the circuitry at the potential
 [ of the AC's "neutral" line you must use half-wave rectification
 [ which has 60 Hz ripple and poor voltage regulation.  Full wave
 [ rectification provides a more satisfactory 120 Hz ripple frequency
 [ and better voltage regulation.  However, if you use full-wave
 [ rectification without an isolation transformer EVERYTHING is "hot"
 [ with respect to the AC neutral.  I'm pretty sure that the
 [ reason that Terry Haughawout's setup is as expensive as it is is
 [ in part due to the cost of the transformer.  What I don't know is
 [ whether he uses a transformer with a turns ratio different from
 [ 1 to 1.  The point is that the Violano is designed to run on 110 V DC,
 [ but the input is 117 V RMS AC (nominal).  The "rub" is that the
 [ capacitors tend to charge up to the PEAK voltage of the AC, not the
 [ RMS value, and the peak value is more like 1.4 times the RMS value.
 [ That means that the no-load DC voltage without an appropriate
 [ transformer is likely to be more like 160V, which is out-of-spec
 [ for the Violano.
 [
 [ Given the cost of the Violano, though, Terry's solution doesn't seem
 [ that expensive...      -- Jody