Surge / Ground / Lightning

[krw]

They did frequency and distinctive rings. But for 2 parties you can ring
red-to-ground for one and green-to-ground for the other. It is in Mike's
Wikipedia link above. My recollection is black was ground and yellow was
sometimes used for a light in the phone (red and green are phone wires).

Princess phones used the yellow green pair for the dial light. A
transformer was hidden somewhere in teh house to supply the power
(IIRC, a standard 24VAC door bell transformer, but it's been a lot
of years).

 

[Mike Tomlinson]

Similarly, I would question the reliability of ring on a single line
referencing
ground, since party lines tended to be out longer distances -- the ground
resistivity
would make it more difficult to get ring current to the phone(s).

It did work though. The mechanical bells in older phones in the UK had
a lower impedance (500 ohm coils vs. 2000 ohm coils in newer phones), so
the ringer would draw more current. The ringer was also two bells
either side of a balanced clapper, so it took little to make it ring -
the more current it was able to draw from the line, the louder it rang.

I remember a neighbour with a party line whose phone had problems -
calling her would give a ring tone in the earpiece, but she would claim
that she had never heard the phone ring. Several visits from the GPO
(as was BT) engineers found no fault, the phone always working when they
visited.

Eventually it was discovered that her party line was grounded via the
waste pipe (lead pipe into a cast iron stack disappearing into the
ground) of her cloakroom toilet, which was little used, and in the
summer, when the ground dried out and the water in the toilet pan
evaporated and ran low, the phone lost its earth and failed to ring.
Flushing the toilet restored normal operation to the phone

 

[krw]

The lamp was on yellow & black. Red & Green are the pair to the CO.

<slap!> There I was typing, looking at bud-'s post and *STILL* got
the wires crossed. I *shoulda* had a V8.

 

[Tzortzakakis Dimitrios]

| [email protected] wrote:
|> In alt.engineering.electrical Timothy Daniels
|>
|> | Would you please sum up what you believe to be prudent
|> | protection (for electronic equipment) from nearby lightning strikes?
|> | I'm thinking of both in single-family homes and in condo/apartment
|> | buildings. What would you do to protect from in-house (or
in-building)
|> | surges, such as elevator motors suddenly shorting out, or welding
|> | equipment in use?
|>
|> How much money are you willing to spend?
|>
|
| The only thing I can think of that comes close is to have a heavy
| motor/generator set with a HUGE flywheel sitting in the basement.

How about driving a generator in the basement with either a heavy
fiberglass
axle rod driven at some distance by a (sacrificial) motor, or by a fluid
that
does not conduct electricity through a turbine system, similarly driven by
a
motor/pump at some distance.

Or a compelete diesel-hydraulic locomotive? (Diesel-hydraulic coupling,
Dieselhydraulische in german)?



--
Tzortzakakis Dimitrios
major in electrical engineering
mechanized infantry reservist
hordad AT otenet DOT gr
NB:I killfile googlegroups.