A Mutual Blocking Technology Applied to Dual Power Source Switching Control

In many industries and medical power system applications, dual power source design is often used to ensure that the equipment runs continuously, even when the main power supply is shut down. However, the voltage feedback between two independent power supplies and low loss output are critical issues for the system energy dissipation. Without using a dedicated chip, a new mutual blocking control technology is proposed in this paper to effectively solve the problem of voltage feedback existing in the conventional dual power system. In addition, without adding much hardware cost, the proposed dual power switch design can completely avoid voltage feedback and achieve a low voltage loss of about 30 mV when the load current is less than 0.5 A.