Classification of switching power supplies, AD/DC power supplies and DC/DC power supplies in detail

Classification of switching power supplies, AD/DC power supplies and DC/DC power supplies in detail

Classification of switching power supply
People's switching power supply technology field is the side of the development of related power electronic devices, the side of the development of switching inverter technology, the two promote each other to promote the switching power supply each year to more than double-digit growth rate toward the light, small, thin, low noise, high reliability, anti-interference direction of development. Switching power supply can be divided into two categories of AC / DC and DC / DC, DC / DC converter has now achieved modularity, and design technology and production processes at home and abroad have matured and standardised, and has been recognised by users, but the modularity of the AC / DC, because of its own characteristics make the process of modularity, encountered in the modular process, a more complex technology and manufacturing process issues. The following are two types of switching power supply structure and characteristics are described.

DC/DC converter
DC/DC conversion is the conversion of a fixed DC voltage into a variable DC voltage, also known as DC chopper. Chopper works in two ways, one is the pulse width modulation method Ts is unchanged, change the ton (general purpose), the second is the frequency modulation method, the ton is unchanged, change the Ts (prone to interference). Its specific circuit consists of the following categories:

(1) Buck circuits - buck choppers, whose output average voltage Uo is less than the input voltage Ui, with the same polarity.

(2) Boost circuits - boost choppers, whose output average voltage Uo is greater than the input voltage Ui, with the same polarity.

(3) Buck-Boost circuit - Buck or Boost chopper whose output average voltage Uo is greater or less than the input voltage Ui, with opposite polarity and inductive transfer.

(4) Cuk Circuit - Buck or Boost Chopper with an average output voltage Uo greater or less than the input voltage Ui, opposite polarity, and capacitive transfer.
Today's soft-switching technology makes a qualitative leap in DC/DC, the U.S. VICOR company designed and manufactured a variety of ECI soft-switching DC/DC converter, its * large output power of 300W, 600W, 800W, etc., the corresponding power density of (6, 2, 10, 17) W/cm3, the efficiency of (80-90) per cent. Japan's NemicLambda company * newly introduced a soft-switching technology of high-frequency switching power supply module RM series, its switching frequency (200-300) kHz, power density has reached 27 W/cm3, the use of synchronous rectifier (MOS-FET instead of Schottky diode), is the entire circuit efficiency increased to 90%.