Aha!! A high tech funda!! Let an Electrical Engineer put in his 2 paisa
worth!!
The Facts -
The electrical energy dissipated in 5 second lightening can power a small
city for 24 hours. The lightening voltage is very high and may exceed 10
million volts. This can be best arrested by Lightening arrestor mounted on
top of building ( A spear shaped metal rod connected to ground).
The warning -
In case of thunder storm disconnect all the cables (telephone, cable TV,
Cable modem ) coming from out side (if possible) or at least stay away from
these cables.
>Well better lose the R, it will simply weaken the signal or supply even
>under normal operating conditions. A capacitor has all the disadvantages
>of a shunt regulator, besides if it fails you're still screwed. If a
The electronic circuits are protected from lightening with a varistor, which
is a variable resistance. This resistance offers a low resistance to fast
rising voltage (which is what is lightening) thus discharging the high
voltage. But many times these varistor gets damaged while protecting the
circuit ( ..a true martyr ). Every modem (win or otherwise ) has one on
Telephone line termination, so there is no need to worry.
>coil fails, since it is in series with the line, your hardware will be
>essentially disconnected and hence safe. But go on ahead, open your
>hardware (no pun intended) and solder a capacitor with a C value small
>enough to pass your highest operating frequency (few 100 Khz for dial up
>telephone) but with a voltage rating of 2 million volts. Do mail and
The telephone line can not transmit frequency of more that 5 kHz, The baud
rate (33.3 KBPS or 56.6 KBPS ) mentioned on modem are achieved with
amplitude and phase modulation.
>hardware (no pun again) during a storm.
>> What do the knots do, then? As the wire becomes noticeably thicker at
>A changing current through a wire sets up an electric field that opposes
>the current that set it up. The knots and coils simply help to
>concentrate the magnetic field to be more efective. A surge is a very
>rapidly changing current (almost infinite frequency). Thus the knots
>won't affect your normal operation much but will oppose the surge.
The coil will not serve any purpose because inductance thus created will be
in micro henry and the lightening is not of high frequency. It is a single
pulse of very high voltage followed by harmonics of low voltage. The damage
will be caused by the first pulse only.
Regards,
Mukund Deshmukh
Beta Computronics Pvt. Ltd.
Web Site - www.betacomp.com
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