Several types of switching power supplies are classified and introduced as follows:
① AC/DC power supply, also known as primary power supply, takes energy from the power grid, rectifies and filters it to obtain a DC high voltage, which is used by the DC/DC converter to obtain one or several stable DC voltages at the output terminal. The power range is from a few watts to several kilowatts and is used in different occasions. There are many specifications and models of this type of product, and the primary power supply (AC220 input, DC48V or 24V output) in the communication power supply can also be classified according to user needs
② DC/DC power supply, also known as secondary power supply in communication systems, is a DC input voltage provided by a primary power supply or a DC battery pack. After DC/DC conversion, one or several DC voltages are obtained at the output terminal.
③ Communication power supply is essentially a DC/DC converter type power supply, but it is generally powered by DC-48V or -24V and backed up by a backup battery to convert the DC supply voltage into the working voltage of the circuit. It is generally divided into three types: central power supply, layered power supply, and single board power supply, with the latter having high reliability.
④ The power supply of the radio station has an input of AC220V/110V and an output of DC13.8V. The power is determined by the power of the radio station supplied, and there are products available in several amps and hundreds of amps To prevent power outages in the AC power grid from affecting the operation of the radio station, a battery pack is required as a backup. Therefore, this type of power supply not only outputs a 13.8V DC voltage, but also has the function of automatically switching battery charging.
⑤ With the rapid development of science and technology, modular power supplies have increasingly high requirements for power reliability and capacity/volume ratio. Modular power supplies are showing their superiority, with high operating frequency, small size, high reliability, and easy installation and combination expansion. Therefore, they are becoming more and more widely used. At present, although there are corresponding module productions in China, the failure rate is relatively high due to the production process not catching up with international standards. Although the cost of DC/DC module power supply is currently high, considering the overall cost of the product's long application
cycle, especially the high maintenance costs and reputation losses caused by system failures, choosing this power module is still cost-effective. It is worth mentioning the Roche converter circuit, which has the outstanding advantages of simple circuit structure, high efficiency, and output voltage and current ripple values close to zero.
⑥ Special power supplies such as high-voltage low current power supplies, high current power supplies, and AC/DC power supplies with 400Hz input can be classified into this category and selected according to special needs. The price of switch mode power supplies is generally 2-8 yuan/watt, and the price of special low-power and high-power power supplies is slightly higher, up to 11-13 yuan/watt.
