Re: Redundancy/Survival

From	Robert Riches <spamtrap42@jacob21819.net>
Newsgroups	comp.os.linux.misc
Subject	Re: Redundancy/Survival
Date	2026-05-30 04:00 +0000
Organization	none-at-all
Message-ID	<slrn111ko6h.q66.spamtrap42@one.localnet> (permalink)
References	(7 earlier) <FPIRR.2$XSac.0@fx03.iad> <20260527140256.00006742@gmail.com> <O-CdnbSPFZ9AaYr3nZ2dnZfqnPSdnZ2d@giganews.com> <slrn111hvoh.1js.spamtrap42@one.localnet> <UYicndOFJtzCvIT3nZ2dnZfqnPSdnZ2d@giganews.com>

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On 2026-05-29, c186282 <c186282@nnada.net> wrote:
> On 5/28/26 22:50, Robert Riches wrote:
>> On 2026-05-28, c186282 <c186282@nnada.net> wrote:
>>>
>>>     I still have a few NON-digital phone sets.
>>>     Plug in - they Just Work.
>> 
>> Also, if you need private point-to-point phone capability
>> (without ringer), two old-style phone sets and a 9V battery
>> suffice.  Just connect everything in series.
>> 
>> About 30 years ago, I did that with two very old rotary phones
>> and a 9V battery between the bedrooms of my two daughters.  They
>> decided knuckles knocking on the wall between the rooms would be
>> their signal to pick up the phone.  When either phone set (or
>> both) hung up, battery current was close enough to zero that the
>> battery would last a very long time.
>
>    Hmmm ... can you render a simplified schematic ?
>
>    Sounds like a basic "intercom" system, but might
>    have wider uses. A mere PI or Arduino might expand
>    the horizon considerably.
>
>    If the Big Providers won't run their copper network
>    then maybe we mere proles can find uses for what's
>    still connected ?

A simplified schematic?  I don't have a picture handy or a
convenient way to draw one.  However, the circuit is simple
enough that the topology is limited by the solution space.  I can
describe it in a lot fewer than a thousand words:

1. Draw a circle in pencil so you can erase it later.

2. Put the phones and battery at points about 120 degrees apart
   on the circle.

3. Draw the terminals on or near the circle.  There should be two
   terminals per element.

4. Add three wires, one connecting the closest terminals of each
   pair of elements.

5. Erase the circle, but leave the rest.

At least with old carbon-mike-type phone sets, the circuit will
operate independent of polarity, as long as the three elements
form a ring (no pun intended).

-- 
Robert Riches
spamtrap42@jacob21819.net
(Yes, that is one of my email addresses.)

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Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 02:21 -0400
  Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-26 08:46 +0200
    Re: Redundancy/Survival Marco Moock <mm@dorfdsl.de> - 2026-05-26 09:49 +0200
      Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 04:47 -0400
      Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-26 11:25 +0200
      Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-05-26 09:53 +0000
    Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 04:38 -0400
      Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-26 11:35 +0200
      Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-05-26 22:09 +0000
        Re: Redundancy/Survival John Ames <commodorejohn@gmail.com> - 2026-05-26 16:17 -0700
          Re: Redundancy/Survival Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-05-27 00:02 +0000
            Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-27 00:11 -0400
              Re: Redundancy/Survival Marco Moock <mm@dorfdsl.de> - 2026-05-28 10:32 +0200
            Re: Redundancy/Survival Nuno Silva <nunojsilva@invalid.invalid> - 2026-05-27 08:41 +0100
              Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-27 11:04 +0200
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 03:31 -0400
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-28 09:18 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-28 13:42 +0200
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-28 15:01 +0100
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 21:34 -0400
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-29 11:07 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-29 12:55 +0200
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-29 12:14 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-29 13:36 +0200
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-29 13:26 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-29 19:36 +0200
                Re: Redundancy/Survival Richard Kettlewell <invalid@invalid.invalid> - 2026-05-29 17:24 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-29 19:37 +0200
                Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-29 19:36 +0100
                Re: Redundancy/Survival Richard Kettlewell <invalid@invalid.invalid> - 2026-05-29 22:34 +0100
                Re: Redundancy/Survival Rich <rich@example.invalid> - 2026-05-29 04:30 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-29 01:34 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 06:36 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-29 02:17 -0400
                Re: Redundancy/Survival not@telling.you.invalid (Computer Nerd Kev) - 2026-05-30 09:09 +1000
              Re: Redundancy/Survival Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-05-27 20:51 +0000
                Re: Redundancy/Survival John Ames <commodorejohn@gmail.com> - 2026-05-27 14:02 -0700
                Re: Redundancy/Survival not@telling.you.invalid (Computer Nerd Kev) - 2026-05-28 08:54 +1000
                Re: Redundancy/Survival Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2026-05-28 05:04 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 03:54 -0400
                Re: Redundancy/Survival Andy Burns <usenet@andyburns.uk> - 2026-05-28 09:15 +0100
                Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-28 13:45 +0200
                Re: Redundancy/Survival Robert Riches <spamtrap42@jacob21819.net> - 2026-05-29 02:50 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-29 01:17 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 06:48 +0000
                Re: Redundancy/Survival Robert Riches <spamtrap42@jacob21819.net> - 2026-05-30 04:00 +0000
          Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 23:41 -0400
            Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-27 14:09 +0100
              Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 03:51 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-28 17:08 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 22:14 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 04:41 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-29 01:53 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 06:32 +0000
        Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 22:39 -0400
          Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-27 14:10 +0100
            Re: Redundancy/Survival not@telling.you.invalid (Computer Nerd Kev) - 2026-05-28 09:05 +1000
              Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-28 08:19 +0100
            Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 03:52 -0400
              Re: Redundancy/Survival The Natural Philosopher <tnp@invalid.invalid> - 2026-05-28 09:20 +0100
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-28 20:34 -0400
                Re: Redundancy/Survival InterLinked <usenet@phreaknet.org> - 2026-05-28 21:07 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 01:21 +0000
                Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-29 02:08 -0400
                Re: Redundancy/Survival rbowman <bowman@montana.com> - 2026-05-29 06:41 +0000
  Re: Redundancy/Survival Marco Moock <mm@dorfdsl.de> - 2026-05-26 09:44 +0200
    Re: Redundancy/Survival c186282 <c186282@nnada.net> - 2026-05-26 04:45 -0400
    Re: Redundancy/Survival "Carlos E.R." <robin_listas@es.invalid> - 2026-05-26 11:38 +0200
  Re: Redundancy/Survival "Worst Case" <fritz@spamexpire-202605.rodent.frell.theremailer.net> - 2026-05-26 17:21 +0200

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