Answer / r. d.

- 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
or corrosion/electrolysis.

Answer / k.prakashchandra

positive is earthed ?

Answer / cnu

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.

Answer / shivareddy

Equipments which is used in telecom field Designed
for -48volts

Answer / vinayak.kadam

no idea???

Answer / ratikanta mekap

because all of the electronics equipments used in telecom
field(bts,tx-rx rack,mux etc)are working in dc supply,so
that this is happen.

Answer / u.chandarasekar

Why Because Earthing contrctor Earn money so that

HI SIR, AM PREPARING FOR RRB FOR SECTION ENGINEER POST. PLZ SEND ME THE PREVIOUS QUESTION PAPERS AND HELP ME. I HAVE NO ENOUGH TIME MY EXAM DATE IS 22ND JUNE.... MY EMAIL ID IS nalla.amarnath@gmail.com

0 Answers  

How to use computer cpu ups use for home inverter circuit board

0 Answers  

What is the effect on Power factor and capacitor when your company load is more than 70 % of welding transformer

0 Answers  

what is the safe meggar values for motor, transformer HT, LT and Cables?

12 Answers   IOCL, Jindal, TATA,

What is the difference between AC Drives and DC Drives?

14 Answers   College School Exams Tests, La-Gajjar Machineries, LG, Schneider, SMEL,

how many units will 100 kvar capacitor consume for one day?

2 Answers   Philips,

what is tha gap between the pole of 132kv line

2 Answers  

my diploma certificate in my higher education college

0 Answers   Aastha Spintex,

how define the torque in ac drive. from electrical side in the drive friquency ,voltage and current three factor is there.

0 Answers  

what is the current carrying capacity of 725 va generator

2 Answers  

What is spill current in protection relays?

1 Answers  

What is Transformer?

23 Answers   HSL,