Why negative voltage is used in telecom

Not the fact that its forty-eight volts or that its DC, but that its negative (the positive terminals of the batteries are “ground”). Why most telecommunication equipment use -48V supply voltage. In summary ( from the thread):.

V (or in the UK, 50V) seems to be arbitrary, many of the earlier CB systems of the Post Office used volts or volts. My remote guess is that it is also used to discourage the users from connecting any other circuit at their premises to this power supply as nearly all electronic circuit use positive voltage .

Positive voltage eats the copper wires if they get wet.

Lightening strikes are positive most normally and this allows filtering to ground these while not impacting the signal.

No, not all telecom BTS use -48V power supply. Voltage is simply difference of potential between two terminal on any power source. For device perspective negative or positive voltage is not an issue, important is to . Why is the positive side of the DC circuit connected to ground in telecom applications versus negative ground used , as used , in automotive and other industrial dc systems? How does connecting one pole to the ground make any difference?

Does it zero the pole so that it becomes neutral? LARGE majority of equipment in the telecom world runs at -48VDC. The negative voltage is used to . The answer to negative polarity is cathodic protection , First developed to keep the copper hulls of British naval ships from corroding, this technology has been applied to protecting everything from oil rigs to gas pipelines to telephony cabinets. Dc is used in the telecommunication circuit.

A negative line voltage helps to reduce the corrosion from. Normally in automobile dc system negative is earthed. Negative - is giving to the equipment. This design is targeted for telecom applications because this negative supply voltage is used with the most common of telecom equipment.

A DC Power Supply System converts the AC power to DC Voltage , to charge the batteries and to supply the Telecom equipment (load) when. This ensures that its negative 48V DC output level does not decrease or become noise degraded as the battery voltage transitions from its fully charged to its fully depleted level. Many DC-DC converters for telecommunications have all- aluminum housings with anodized finishes which make them inert and . Graduate Telecommunications Program.

When you measure voltage you choose one terminal to be the reference and the other terminal determins the polarity. Usually copper wires are used in .