Basically for any electronic device it needs a DC supply as
a source power the different components inside it.
everybody knew that the telephone in our houe will not
contain any supply line (speaking about basic model) other
than the one that comes from the exchange. but how is the
Electronic board inside the telephone is working?
this line carries a DC voltage of 48V (42V to $8V approx).
this voltage supplies power to the components inside the
telephone as well as carries the voice signals from
exchange to our phone and vice versa.
- 48 VDC is used in telecom to prevent corrosion or
electrolysis. If you use +48VDC there are free electrons
raging to go somewhere, as each electron is lost, you lose
what is part of a molecule of copper, thus the copper
corrodes away, lines corrode away until they break! -48VDC
wants electrons so it attracts molecule = no loss of copper
A three phase load, around 4 km away from the 11/0.433KV
distribution transformer (Neutral of Transformer is
solidily earthed) and consisting of mainly very costly and
sensitive electronic equipments is giving trouble due to
high voltage difference between neutral and body earth.
Whether this problem can addressed by connecting neutral at
the load point solidly to earth?