Thread
:
12 volt Home electrical system?
View Single Post
#
19
Posted to alt.home.repair
Mark Lloyd
external usenet poster
Posts: 1,963
12 volt Home electrical system?
On Tue, 07 Nov 2006 02:17:01 GMT,
(Beachcomber)
wrote:
Correct. Momentary switches. The 24V is rectified, so
a DC pulse is applied to one winding or the other of the relay.
The relay then latches magnetically and needs no more input power.
A switch anywhere else in the house can then cause the relay to
change state.
A nice application is a large property where outside lights
can be switched on/off from dozens of indoor locations.
Or, a bank of switches can control *any* light in the house from
one location!
The system *did* catch on and was quite popular.
But this was 40 years ago!!
I remember these. It was sort of like an X10 system with wires.
One big problem was maintenance. These were usually installed in a
home during the original construction. The relays were mounted in
electric box cutouts with the relay mechanism outside the box and
inaccessible behind the plasterboard.
If a relay went bad, it was almost impossible to replace it without
smashing a hole in the wall.
The switches also went bad, from time to time. They were really no
more than SPDT momentary doorbell buttons.
I didn't know they made SPDT doorbell buttons. Every one I've seen has
been SPST. SPST would be enough for controlling relays too.
Beachcomber
--
49 days until the winter solstice celebration
Mark Lloyd
http://notstupid.laughingsquid.com
"God was invented by man for a reason, that
reason is no longer applicable."
Reply With Quote
Mark Lloyd
View Public Profile
Find all posts by Mark Lloyd