Multi-module parallel input circuit for reverse connection prevention, overvoltage and undervoltage protection and isolation startup and shutdown

The invention discloses a multi-module parallel input circuit for reverse connection prevention, overvoltage and undervoltage protection and isolation startup and shutdown. The multi-module parallel input circuit comprises a reverse connection prevention circuit, an overvoltage protection circuit, an undervoltage protection circuit, a multi-power-supply-module parallel input circuit and an isolation startup and shutdown circuit. The circuit has the advantage of realizing the functions of reverse connection prevention, overvoltage and undervoltage protection and isolation startup and shutdown. A reverse connection prevention circuit is realized by using a PMOS transistor and a voltage stabilizing tube, so that the module is prevented from being damaged by reverse connection input. The voltage stabilizing tube and the triode are used for realizing an overvoltage and undervoltage protection circuit, and the module can still work normally when normal voltage is input again after overvoltage and undervoltage; and