Load state detection circuit and method

A load state detection circuit, comprising:

• at least one detecting power supply, a voltage sampling circuit, a switch unit, and a microcontroller;
• wherein the microcontroller is connected to the switch unit, the switch unit is connected between the detecting power supply and the load to be tested;
• wherein a voltage sampling point is formed at either terminal of the load to be tested, and the voltage sampling circuit is connected between the voltage sampling point and the microcontroller;
• wherein the voltage sampling circuit is configured to sample a voltage at the voltage sampling point, and output the voltage to the microcontroller;
• wherein the microcontroller is configured to, before conductively connecting the load to be tested with the drive power supply, electrically connect the load to be tested and the detecting power supply by controlling the switch unit, and determine whether a fault exists occurring to the load to be tested according to a received voltage at the voltage sampling point sampled by the voltage sampling circuit;
• wherein the load state detection circuit further comprises a first voltage divider circuit;
• wherein the switch unit is connected to a first terminal of the first voltage divider circuit, a second terminal of the first voltage divider circuit is connected to an terminal of the load to be tested, and a third terminal of the first voltage divider circuit is grounded;
• wherein the microcontroller is configured to:
• control the switch unit to switch on;
• and
• determine that a grounding short circuit fault occurs to an terminal of the load to be tested where no voltage sampling point is formed when a received voltage at the voltage sampling point is within a first preset range;
• wherein the first preset range is set according to a resistance of the first voltage divider circuit, an internal resistance of the load to be tested, and a voltage of the detecting power supply.