Why do we use 48V power supply?

The choice of 48V was to maximize the distance between the user and the end office under the conditions at the time (36V is a safe voltage, and it is unsafe to exceed too much). Later, in order to be compatible with early equipment and reduce costs, the central office communication equipment still used -48V power supply.

Can a 48 volt DC power supply save a data center?

(Fig. 5) As shown in this example, when the power per rack exceeds 10 kW, the power distribution loss generated by traditional 12-V DC power is said to reach an intolerable level, but a 48-V DC power supply significantly contributes to power saving for a data center.

Why is 48 a good system voltage?

Back in the day, when Telephony equipment was being developed, 48 was the chosen system voltage because it’s considered safe “low voltage”, and reduced amperage requirement of equipment powered at this voltage.

What is the operating voltage range for -48V system equipment?

For -48V system equipment, the required operating voltage range is -38.4V ~ 57.6V, but in fact we generally require the operating range -36V ~ -72V. The main consideration is that -48V system equipment must be compatible with –60V power supply system, which requires –48~-72V.

Can a 48-V DC converter be used with a 12-V DC power supply?

When a 48-V DC power feeding is adopted, the power configuration of the DC/DC converter needs to be changed from the 12-V DC power supply. Briefly described, two methods are used. The single-stage method reduces the 48-V power source to the load voltage by using a single power supply.

Why did Bell choose -48VDC?

In the late 1800’s, most homes of were not yet wired for electricity; in fact, communications beat power to the home in much of the United States. The reason Bell selected -48VDC is because it provides enough in power to support a signal, but not enough to be dangerous.