The reason why the output of the DC power supply becomes negative
The reasons for the negative output of the general DC power supply:
The DC converter is to convert a fixed DC voltage into a variable DC voltage. This technology is widely used in the stepless speed change and control of trolleybuses, subway trains, and electric vehicles. At the same time, the above control can achieve smooth acceleration and fast response. performance, and at the same time receive the effect of saving electricity.
Replacing the varistor with a DC chopper can save power by (20~30)%.
The DC chopper can not only play the role of voltage regulation (switching power supply), but also can effectively suppress the harmonic current noise on the grid side.
The secondary power DC converter of the communication power supply has been commercialized. The module adopts high-frequency PWM technology, the switching frequency is about 500kHz, and the power density is 5W~20W/in3.
With the development of large-scale integrated circuits, power modules are required to be miniaturized, so it is necessary to continuously increase the switching frequency and adopt new circuit topologies. The power density of the secondary power module is greatly improved.
