Light current:
low voltage, low current, low power, but high frequency. The main point to be considered is the quality of signal delivery, including fidelity, speed, breadth, and reliability. Light current is generally divided into two categories: one is the low-voltage electric energy that belongs to national-standard safety grade, including Alternating Current (AC) and Direct Current (DC). 24V DC power and the spare power of emergency light both belong to this category. The other one is loaded with the signal source of sound, image, and data, such as A/V, network, and telephone lines, which is generally within 36V DC. The signal inputs of telephones, computers, televisions (CATV), outputs of acoustic equipment, PA systems, and building auto-control systems (door access and security) all belong to light-current electrical equipment.