[geeks] Wireless Routers

[nate at portents.com]

> I'm not so sure.  There are at least half a dozen different voltages in
> common use, and probably a bunch more in less common use.

You're thinking that somehow we can't step down DC voltage (technically or
economically), but today we can - we have the semiconductor technology,
and it's affordable (thyristors, IGBTs, MOSFETS, etc.)

Look where the technology is going, even on a small scale - we're already
moving beyond analog VRM technology in motherboards with the unreliable
and high waste-heat generating capacitors to much more efficient digital
VRMs something IWill and others have already incorporated into many
products). We have the technology to convert and control current with
semiconductor technology very efficiently now.

> There are also assorted technical challenges, like distributing
> low-voltage DC at reasonable aggregate current without too much drop
> due to wire losses.

That's accomplished by high-voltage direct current electric power
transmission, something the Swedish company Allmdnna Svenska Elektriska
Aktiebolaget first developed in the 1930s.

> Mains voltage has the advantage of being standardized.  There are a few
> different standards, but they are pretty much completely separated
> geographically.

And I'm talking about a new global standard for DC current.

> Depends on the house.  I know some people who have little other use for
> electricity.  At the extreme end, my mother probably has nothing that
> uses a power supply in the sense of having most of its circuitry
> running off non-mains voltage: stove, 'fridge, electric lights, and I
> think that's it.  Last I knew she didn't even have a radio.

The time of the incadescent bulb is over, full spectrum LED lighting is
coming and it's DC.  So what have we got left at your mom's house then if
she switches to the much more affordable (in the long run) and energy
efficient LED lighting?  Her stove and fridge.  Probably her vaccuum
cleaner, clothes washer and dryer too.  But I'm not saying we should do
away with AC right away, I'm saying it should be augmented with DC, either
with a single big converter for the home, or with HVDC long distance
transmission lines (which in some cases make inverters cost-effective).

If this was 1920 or even 1970 (i.e. a time before solid state HVDC
technology), I might agree with you that AC would be preferable in all
cases.

- Nate