Uninterruptible Mains Power Supply with Soft Switching of Power Transistors

An uninterruptible power supply for automation and communication devices is presented, which contains all the units required for operation from industrial grids, switching to battery power, battery charging, monitoring operating modes, and protection systems. The source implements soft switching of power transistors in a wide range of supply voltages and load currents. Results of circuit modeling in the LTspice system and prototype tests are presented, confirming the correctness of the described approach to selecting the parameters of the power-supply circuit needed to obtain the required characteristics.