Potential difference early-warning circuit and system

A potential difference early-warning system, comprising the potential difference early-warning circuit;

• wherein the potential difference early-warning circuit comprises:
• a sensing resistor, one end of the sensing resistor being connected to a signal ground;
• a first Metal-Oxide-Semiconductor Field-Effect Transistor (MOS), a drain of the first MOS being connected to the other end of the sensing resistor, and a source of the first MOS being connected to a safety ground;
• an operational amplifier, a positive input end of the operational amplifier being connected to one end of the sensing resistor, and a negative input end of the operational amplifier being connected to the other end of the sensing resistor;
• a second MOS, a gate of the second MOS being connected to an output end of the operational amplifier, and a source of the second MOS being connected to the signal ground;
• and
• a controller, a first input end of the controller being connected to the drain of the second MOS, and an output end of the controller being connected to the gate of the second MOS;
• wherein the operational amplifier is configured to send a corresponding level to the second MOS according to a magnitude of a potential difference between the signal ground and the safety ground, so as to control the second MOS to be turned on or turned off, so that the controller receives the corresponding level through the first input end, and then the controller controls the first MOS to be turned on or turned off according to the received level.