"SMS" wrote in message
...
Robert Green wrote:

stuff snipped

Can I calculate the voltage drop just by observation? (Measure battery
voltage at one end and then through the run of wire to see how many
volts
remain and how much more than 12VDC I need to push through the wire to
get
12VDC at the front gate?)

Run 24VAC to the gate, and then use a 24VAC to 12VDC converter, i.e.
Google "SECUREMAX: AT12015".

Is it that long a run that I'll be losing significant amounts of power using
DC? I already have a variable voltage switching power supply gizmo I intend
to use for the project that uses one coaxial cable to send audio, video and
power. It comes with a variable voltage power supply and an adapter on each
end to inject and extract the audio and video from the cable.

Will there be a substantial or even significant savings in my electric bill
gained by using 24AC and then converting it to DC? Is the conversion done
to save power or mostly to deal with the problem of voltage drop over long
runs of DC cable? I've seen these devices in CCTV catalogs, so it seems
like they are a popular solution. I'd just like to understand the tradeoffs
a little better.

For low voltage wiring, you don't need to go very deep, 6-8" and
hopefully gas and water lines are a lot deeper than that.

Good. I've read all sorts of disaster stories about frost heaving the
ground and unburying the wires in some electrical nightmare version of the
movie Poltergeist. I just don't want to one day catch the lawnmower up in
wires that have unburied themselves.

Conduit is nice, to keep the wires clean and together and protected,
though low voltage outdoor wiring is often just buried without conduit
(i.e. sprinkler valve wiring). I put it inside PVC pipe.

Conduit's going to add to the cost and complexity of the job, and I'd like
to avoid it if burial grade cable is "good enough" to get the job done.

Thanks for your input!

--
Bobby G.