Power supply system with AC redundant power sources and safety device

A power supply system comprising:

• a plurality of power supplies which are connected in parallel for outputting a voltage;
• a plurality of power sources, each of said power sources is directly coupled in series with a corresponding one of said power supplies to provide a voltage to operate said corresponding one of said power supplies;
• and
• a control circuit coupled between said power sources and the power supplies except those said respective power supplies and power sources which are directly mutually coupled in series, for creating a conductive path to transfer a voltage from one of said power sources except those which are interrupted in providing voltages to operate said power supplies;
• wherein said control circuit comprises:
• a safety device for preventing said power sources from getting short circuited;
• one of a plurality of switch circuits coupled in series with one of said power sources and said safety device for receiving a voltage from said one of said power sources and transferring to said safety device;
• and
• a voltage transfer circuit coupled between said safety device and said one of said power supplies except those said respective power supplies and power sources which are directly mutually coupled in series, and configured to be switched near a zero-crossing point of the voltages from said power sources, for alternatively creating a conductive path in response to a control signal to provide the voltage being transferred from one of said switch circuits to said one of said power supplies.