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Why -48V dc power supply using in telecom field?

Answer Posted / 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.

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