Novel input reverse-connection-preventing circuit

The invention relates to a novel input reverse-connection-preventing circuit which comprises a reverse-connection-preventing diode D1, wherein the positive pole of the diode D1 is connected with the input end of a direct-current power supply, the negative pole of the diode D1 is connected with a load, and a relay JK1 is connected in parallel to the reverse-connection-preventing diode D1. According to the invention, when the input positive and negative poles are connected correctly, the current after flowing through the input positive pole, the reverse-connection-preventing diode D1 and the load flows back to the input negative pole, then the relay JK1 is closed, the current after flowing through the relay JK1 and the load flows back to the input negative pole, and in the process of normal operation, the circuit disclosed by the invention does not consume energy and causes no effect on efficiency. When the input positive and negative poles are connected reversely, because of the existence of the reverse-connection-preventing diode D1, no current is generated in the circuit, and the load is not started, thereby achieving an effect of protecting the circuit. The circuit disclosed by the invention is simple in structure and high in reliability.