Improved circuit structure in radar fault diagnosis system

The utility model discloses an improved circuit structure in a radar fault diagnosis system. The circuit structure is installed in a test fixture. The circuit structure includes an optical coupler, first to third resistors, a triode, a Hall sensor, a relay and a controller. An input end anode of the optical coupler is connected with a +3.3V power supply and an output end emitting electrode of the optical coupler is grounded, an output end collecting electrode of the optical coupler is connected with a +5V power supply and an output end collecting electrode of the optical coupler is also connected with a base electrode of the triode through the first resistor. The base electrode of the triode is also connected with an emitting electrode through the second resistor, a collecting electrode of the triode is connected with a +12V power supply after passing a main coil of the collecting electrode, and the emitting electrode of the triode is grounded. A radar is connected with one end of the third resistor after passing a main contact of the relay. The other end of the third resistor is grounded after passing the Hall sensor. The Hall sensor is also connected with the controller. The improved circuit structure is capable of detecting whether the radar has residual current through the Hall sensor and thus the security performance of the radar is improved significantly.