GND (Ground) and COM (Common) are in different scenarios with different meanings and connections. Understanding and connecting GND and COM is crucial for the normal operation and safety of the circuit.
I. Definition and difference between GND and COM
GND (Ground): refers to the reference ground or zero potential point of the circuit, which is the reference voltage point of the whole circuit. GND is connected to the negative pole of the power supply or directly grounded and is used to provide a stable voltage reference.
COM (Common): denotes the common or shared terminal and refers to a connection point shared by multiple circuits or components. com can be GND or other voltage levels depending on the design and application of the circuit.
It should be noted that in some devices, COM may be used to indicate a positive common or other specific function, so the technical manual of the device should be carefully consulted to clarify its definition before use.
II. GND and COM connection method
1. Define the requirements of the device: Before connecting GND and COM, you should first consult the technical manual or circuit diagram of the device to clarify their definitions and uses in a particular device.
2. Connect GND correctly: GND usually needs to be connected to the negative or ground of the power supply to ensure a stable reference voltage for the circuit.
3. Connect COM correctly: Depending on the circuit design, COM may need to be connected to a specific voltage point or used as a common reference point for signals. In some cases, COM may need to be connected to GND, but in other cases they may need to be connected separately to avoid interference.
III. Avoiding Common Misconceptions about GND and COM Connections
Misconception 1: Considering COM as GND: In some circuits, COM is not equivalent to GND, and connecting it directly may cause the circuit to function abnormally or be damaged.
Misunderstanding 2: Ignore the device description: different devices may have different definitions of GND and COM, ignoring the device description for connection may lead to safety hazards or equipment failure.
Misunderstanding 3: Do not consider circuit isolation: In circuits that require electrical isolation, the direct connection of GND and COM may destroy the isolation, leading to interference or safety issues.
IV. Suggestions for correctly connecting GND and COM
Check the technical data: Before making the connection, be sure to check the relevant technical data to clarify the definition and requirements of GND and COM.
Follow the design specifications: Connect according to the circuit design specifications to ensure the functionality and safety of the circuit.
Conduct testing and verification: Before actual application, test the connection without short-circuit, misconnection and other problems.
By correctly understanding and connecting GND and COM, common wiring errors can be effectively avoided, stable operation and safety of the circuit.
