[rescue] SGI Challenge L systems available in Denver

Francisco Javier Mesa-Martinez lefa at ucsc.edu
Fri Sep 17 12:44:43 CDT 2004

On Fri, 17 Sep 2004, Sandwich Maker wrote:

> " From: patrick at mail.zill.net (Patrick Giagnocavo)
> "
> " On Fri, Sep 17, 2004 at 10:57:00AM -0400, Nathan Raymond wrote:
> " >
> " > What's really needed is a large AC->DC converter in the basement and new
> " > DC outlets alongside AC outlets in houses, and devices that work with the
> " > []
> "
> " I was doing some reading on solar power, and this is a hot topic in
> " that community.  Basically where feasible run DC straight from the
> " battery bank, only using AC where necessary.
> "
> " The problem with DC is its perceived danger, and that you need thicker
> " wires for running large loads.
> depends on the voltage.  110vdc doesn't need any thicker wires than
> 110vac, but i assume you must mean 12vdc.

The thickness of the wire has nothing to do with the voltage differential,
you could have 1000V on a hair thin wire: It is them Amps that matter :)
Electrical energy losses are directly proportional to current flow, not to
the energy flow.

The reason for using AC is very simple: It is easier to genreate alternate
current, and AC can be easily stepped up or down. The low voltage/ hight
current generated can be stepped up to high voltage/low current for
transmission (lower loss when the current is smaller), and then it can be
stepped back to low voltage/high current at the destination point. Plus
you can also play with the phase in order to adapt for long distance
distribution, something that can not be done with DC.

More information about the rescue mailing list