The present invention relates to the field of automobile diagnosis, and provides an isolation circuit, an automobile diagnosis device and an automobile diagnosis system. The isolation circuit comprises: a first switch circuit electrically connected between an OBD connector of an automobile to be diagnosed and a diagnostic device of the automobile diagnosis device, wherein the OBD connector is further electrically connected to an automobile power supply of the automobile to be diagnosed; and a switch control circuit electrically connected to the OBD connector and the first switch circuit respectively, wherein the switch control circuit does not operate when it is detected that the OBD connector outputs a power supply positive electrode signal and it is not detected that the OBD connector outputs a power supply negative electrode signal, so that the first switch circuit operates in an off state to ensure that the diagnostic device is not powered on; and the switch control circuit outputs a control signal when it is detected that the OBD connector outputs a power supply positive electrode signal and that the OBD connector outputs a power supply negative electrode signal, so that the first switch circuit operates in an on state so as to enable the automobile power supply to supply power to the diagnostic device. Embodiments of the present invention can avoid poor grounding and improve the reliability of automobile diagnosis device.
ISOLATION CIRCUIT, AUTOMOBILE DIAGNOSIS DEVICE, AND AUTOMOBILE DIAGNOSIS SYSTEM
2022-10-06
Patent
Electronic Resource
English