KNOWLEDGE


1. The product logo is incomplete or irregular.

The label should indicate the details of the product, including normal usage and precautions. Markings need to be durable and eye-catching. After normal use, the markings should not fall off and the contents should be clean and differentiated. If there is no Chinese mark, no factory name or trademark, no model code or model specification, etc., it may be a counterfeit product.


2. Heating under normal working conditions does not meet the requirements.

The function of the power adapter is to change the voltage. During the voltage conversion process, a part of the power needs to be consumed due to the loss. After the electrical energy is converted into thermal energy, part of the thermal energy is transmitted to the surrounding environment by radiation, convection and conduction. Another part of the heat is absorbed by itself, warming the temperature of the power adapter. So when the surrounding ambient temperature is too high, we should stop using the power adapter.


3. Short circuit and overload, there are potential safety hazards.
In the case of output short circuit, capacitor or diode short circuit, the internal loss of the power adapter increases sharply, resulting in temperature rise of each component. The design and application of the electronic circuit should ensure the temperature rise of each part of the product under abnormal working and fault conditions. Do not exceed the specified requirements, otherwise the consequences of the short circuit are unimaginable and may even bring a fire.


  • ​Operating Mode:

Switching power supplies generally have three operating modes: frequency, fixed pulse width mode, fixed frequency, variable pulse width mode, variable frequency and pulse width mode. The former working mode is mostly used for DC/AC inverter power supply or DC/DC voltage conversion; the latter two working modes are mostly used for switching regulated power supply. In addition, the switching power supply output voltage also has three working modes: direct output voltage mode, average output voltage mode, and amplitude output voltage mode. Similarly, the former mode of operation is mostly used for DC/AC inverter power supply, or DC/DC voltage conversion; the latter two working modes are mostly used for switching power supply.

According to the way in which the switching devices are connected in the circuit, the switching power supply can be roughly divided into three categories: a series switching power supply, a parallel switching power supply, and a transformer switching power supply. Among them, the transformer type switching power supply (hereinafter referred to as the transformer switching power supply) can be further divided into: push-pull type, half-bridge type, full-bridge type, etc.; according to the excitation of the transformer and the phase of the output voltage, it can be further divided into: forward type , flyback, single-excitation and double-excited, etc.; if divided into uses, they can be divided into more categories.


  • ​Main Feature:
1. Small size and light weight: Since there is no power frequency transformer, the volume and weight are only 20-30% of the linear power supply.
2. Low power consumption and high efficiency: The power transistor operates in the switching state, so the power consumption on the transistor is small, the conversion efficiency is high, generally 60 to 70%, and the linear power supply is only 30 to 40%.