Why is the power supply voltage of the communication base station -48V DC power supply?
The use of -48V power supply in communication base stations is largely due to historical reasons. Historically, equipment in the communication industry has always used -48V DC power supply. -48V is the positive ground. Because the smallest communication network and communication engineering are all telephone networks, the power supply voltage of the telecommunications bureau is 48V. In order to be compatible with the early equipment and reduce the replacement cost, the later engineering and port communication equipment basically use -48V power supply.
For a voltage higher than 48V, it may cause personal injury. If the voltage is lower than 48V, the current on the line of the load with the same power is too large. It is necessary to choose a thicker power line, which requires a large investment and large line voltage drop loss. +48V and -48V have the same voltage, but the current flows in different directions, +48V flows to 0V, and V0 flows to -48V. The -48V voltage used by the communication power supply is only the communication power supply standard adopted by our country and most countries.
Why choose -48V as the power supply voltage instead of +48V?
1. The voltage is relatively safe. For example, the human body has a 50K ohm resistance, and the voltage is -48V, 48/50000=0.00096A=0.96mA, and the human body will be life-threatening if it flows through 9mA;
2. Grounding the positive pole of the power system can reduce the corrosion of the positive pole of the battery;
3. Reduce system noise and interference;
4. Early communication can use the earth as a loop to save wires;
5. In order to protect the cable from corrosion due to battery reaction, the cable must be negative;
6. The voltage is higher than -24V, which is conducive to power transmission and reduces loss.
Extracurricular knowledge points: Introduction to UPS power supply dedicated for communication base stations
As the power source of the communication base station, the function of the communication base station is to provide us with a stable communication signal source. In the construction of communication base stations, backup protection power supply must be equipped, and we will recommend UPS power supply for customers.
Communication base station UPS power equipment is the foundation and core of the communication system. The transmission, exchange, data and other services of the communication system are all built on this foundation.
In addition to providing power supply to the base station equipment after the mains power failure, the UPS power supply of communication base stations can also solve grid voltage surges, voltage transients, noise voltages, overvoltages, undervoltages, and voltage sags when the mains power is normal. , Frequency drift and other issues. The UPS uninterruptible power supply used in the communication base station can shield interference and provide pure power for the equipment on the one hand, and on the other hand can provide guarantee for continuous and reliable power supply with uninterrupted voltage stabilization.
Advanced green rectification and inverter technology for UPS power supply dedicated to communication base stations, and high-precision SMD technology for fully digital circuits. At the same time, it also has multiple protection functions such as input and output over-voltage protection, input and input surge protection. It can prevent dust, water, corrosion, frost, heat and other super three-proof functions. It is an excellent choice for UPS power supply for outdoor communication base stations.
Energy storage electric lithium battery UPS manufacturer specializes in providing power guarantee for base station construction, focusing and professional. Communication dedicated lithium battery UPS is a new generation of AC communication UPS products of Energy Storage Electric. The communication uninterruptible power supply has the characteristics of integration, miniaturization, light weight, wide operating temperature range, high specific energy, long life, and environmental protection. It can be used indoors. The distributed communication system provides high-quality uninterrupted power supply for the equipment, ensuring full coverage of 2G, 3G, 4G, 5G, WLAN, EPON and other communications.
