The Daring Dufas wrote:
krw wrote:
On Sat, 03 Oct 2009 00:22:41 -0500, The Daring Dufas
wrote:

Bill wrote:
How about getting rid of all those batteries in various devices in
the home and connecting the battery connections to one central battery?

That is to run separate wires when wiring a home and these would
carry say 12 volts DC. There would be a central large battery and
battery charger like the type used in a computer UPS.

Then at each electronic gizmo which needs a battery, use a "battery
eliminator" along with a voltage regulator to supply it with the
correct voltage. And plug this into a nearby 12 volts DC "outlet".

This could provide battery power to smoke detectors, carbon monoxide
detectors, HVAC thermostat, security system, clocks, digital
thermometers, computer UPS, phone answering machine, etc.

Then only ONE battery to worry about...

A 9 volt battery eliminator picture...
http://www.wirelessmicrocolorcam.com... 7a77410624ea



My suggestion would be for a 48 volt DC system.

Think "transformer".

Plain
old telephone service uses 48 volts DC for battery and
PoE, power over Ethernet is usually 48 volts DC.

The maximum "safe" voltage. There is a reason power transmission is
in the hundreds of KV. AC.

The
wire size could be smaller than that for a lower voltage
system and the 78xx type regulators are very inexpensive
and come in a variety of wattage ratings for stepping
down the voltages.

You really want to waste power, don't you?

The technology to pull it off is not
exotic and can be done with all off the shelf parts.
Solar and wind power could integrate quite easily with
such a system.

Not everyone wants to waste ten times the power they use.

Do you have the slightest clue of what the discussion
is about? It's a hypothetical discussion about a DC power
distribution system for a home. I neither seek to impose
a standard or ridicule the ideas of others. I do have about
four decades of experience with all things electrical and
electronic but sadly, I don't know everything. I wish I did.

TDD

I am guessing his point was that linear regulators such as the 78xx
series are quite inefficient.