What is the signal line?

　　The signal line mainly refers to the line used to transmit sensing information and control information in the electrical control circuit. The following is a detailed explanation of the signal line:

　　Definition and function

　　Definition: A signal line is a wire used to transmit various signals generated by a sound source (signal source), which can be audio signals, video signals, digital signals, control signals, etc.

　　Function: The main function of the signal line is to ensure the quality and stability of the signal during transmission. It usually requires good shielding performance and anti-interference ability to reduce the attenuation and distortion of the signal during transmission.

　　II. Types and characteristics

　　Coaxial signal cable: It is the most popular standard signal cable. Both ends are RCA coaxial plugs (commonly known as lotus plugs), which can connect audio source equipment such as CD players, VCD players, DVDs, etc. on the market to audio processing/amplification equipment such as power amplifiers. It belongs to the unbalanced transmission type and has certain anti-interference capabilities.

　　Digital signal line: A type of coaxial signal line that has the same appearance as coaxial signal line and can be used interchangeably. However, its transmission frequency bandwidth and anti-interference ability are stronger than coaxial signal line.

　　Optical fiber (cable) signal line: transmits the digital optical signal from the CD player/DVD player. The digital electrical signal is electrically/optically converted in the CD player and becomes an optical signal transmitted in the optical fiber. The anti-interference ability of the optical fiber signal line is very strong, because the transmitted optical signal is not affected by external electromagnetic waves, and the optical fiber transmission can make the signal between the two have no common ground, avoiding the interference of the common ground wire.

　　Balanced signal line: a high-end audio signal transmission line that suppresses common-mode interference during transmission and is naturally cancelled by an internal differential amplifier, thus playing an anti-interference role.

　　In addition, depending on the number of cores, the signal line can also be divided into 2-core, 4-core, 8-core, 16-core, 24-core and other specifications, which are used to transmit simple switching signals, power signals, audio signals (such as headphone cables or microphone cables), network connections (such as Ethernet cables), and signals from multiple sensors or actuators.

　　III. Application scenarios

　　Communication field: used to connect telephone lines, network cables, optical fibers, etc., to transmit voice, data, and video signals.

　　Electronic equipment: used to connect various electronic devices, such as audio equipment, video equipment, computer equipment, etc., to transmit audio, video, and control signals.

　　Industrial automation: used to connect sensors, actuators, and control systems, transmit various sensor signals and control signals, and achieve automated control and monitoring.

　　Instrumentation: used to connect various instrumentation, transmit measurement signals, control signals, etc.

　　Automotive electronic system: used to connect various electronic devices inside the car to transmit onboard audio, video, control signals, etc.

　　Household appliances: used to connect household appliances and transmit various control signals, such as remote control signals, sensor signals, etc.

　　Medical equipment: used to connect various medical devices, transmit various monitoring signals, treatment signals, etc.

　　To sum up, signal lines have a wide range of application scenarios and important functions in electrical control circuits. Correct selection and use of signal lines is essential to ensure the normal operation of the system and the stable transmission of signals.