Hi!
Do you guys know how to measure the current flowing in our telehone
lines using a multimeter? I really need it badly.
What's the difference between AC Current and DC Current? What will I
use in measuring the current in phone lines?
I'm doing my research regarding the "Electrocution through phone
lines." Have you heard of that urban legend?
Thanks a lot.
There's a show called "Mythbusters" where they approached this very
question and as I recall, their results suggested it was indeed
possible to be electrocuted through a phone line by lightning. Not
likely, but possible under the right conditions.
Google the show and maybe they have that episode online?
As for ringing voltage (ie, no lightning strike), I also recall
reading about a documented fatality from a single D-cell battery!!
(1.5VDC) in Compliance Engineering magazine many years ago (1998-
ish?).
It only takes about 100mA or so, under the right conditions, to stop
the heart. You have to work at it (skin resistance, etc...), but if
you can do it with 1.5VDC, it stands to reason 90VAC (or 90 volts
pulsating DC to be more percise - although by the time it reaches your
phone the edges are worn off quite a bit..), will do the job too.
Finally, when I was younger, I once played around with a Secode rotary
encoder. You know, like the old rotary telephone dials? Only this
one still had the batteries in it. Like an idiot, I was somehow
connected to the leads when I decided to "dial" it and got the crap
shocked out of me!! And yes, in complete accordance with Murphy's
law, I had in fact dialed the "0" for maximum effect.
I immediately set it down, recovered my senses (what little I had
left), and opened the test set to find two old, but apparently well-
charged 45-volt batteries. They looked like 9-volts, only longer.
Lesson learned: Don't assume it's safe, just because it's not plugged
in!
About a month later, I got a refresher in that exact subject while
repairing a foot switch on a Pace vacuum extractor - where the
schematic clearly indicated no line voltage on the foot switch......
Yeah, right.
-mpm