Standard for qualified power adapters
First: to determine the quality of a power supply, check whether it has passed the necessary safety certification.
In general, the more certified a power adapter is, the more reliable its quality. At present, the power supply sold in the market must pass the national compulsory 3C certification system before sales. There are four versions of the existing 3C certificates: CCC(S) safety certification, CCC(SE) safety and EMC certification, CCC(EMC) EMC certification, CCC(F) fire certification. Where CCC(S) only means that a safety standard has been passed.
CCC certification standard (S&E) is being used, it puts forward two safety and emc requirements on power supply, see CCC (S&E) mark on the power supply, can be understood as it passed the 3 c authentication, which is any power supply products must meet the standard, does not mean the quality is excellent, a few brands in the case of a failed to pass the 3 c authentication, will use forged marks to deceive consumers.
In addition to the 3C certification, some advanced power supplies will also see the UL certification mark, which is currently one of the world's most stringent certification, the power supply in the structure, materials, test instruments and methods and other related restrictions. Some high-quality power supplies are also certified by the FCC, which is a certification for electromagnetic interference. An fc-certified power supply will shield the electromagnetic interference generated during its operation and eliminate the harm to human body.
Second: to improve the safety and stability of the circuit to add.
Lightning protection circuit: when the electricity generated by lightning or other factors of high pulse voltage, will damage the equipment on the circuit. The function of the lightning protection device of the power supply is to release the large amount of pulse energy generated by the induction lightning strike on the circuit to the safety line in the shortest time, so as to protect the user equipment on the circuit. This is the core function of the lightning protection device.
EMI filter circuit: the main function of EMI filter circuit is to filter out the interference of external power grid's high-frequency pulse to the power supply, and also to reduce the electromagnetic interference of switching power supply itself to the outside world. EMI is an important part of CCC certification.
PFC circuit: namely, "power factor correction" is mainly used to characterize the utilization efficiency of electrical energy of electronic products. The higher the power factor, the higher the utilization efficiency of electrical energy. Ccc-certified computer power must be equipped with PFC circuit to reduce the harm caused by the circuit power factor reduction.
The quality index of power adapter should be based on the principle of safety and reliability. In order to make the power supply work safely and reliably under the condition that the electrical technical index meets the normal operation requirements, a variety of protection circuits must be designed.