FAQ-Validation
They must be tested for their electrical function, electromagnetic compatibility (EMC), safety, and reliability, to be verified as safe products.
Electrical function includes requirements such as input and output features, timing,efficiency and protection function; EMC includes conduction, radiation, lightning surge, and electrostatic discharge (ESD); safety includes insulation, withstand voltage, leakage; while reliability includes eco-friendly, life, and mean time between failures (MTBF).
MTBF refers to the average continuous operating time without failure.
The most widely used standards include MIL-HDBK-217F, Telcordia SR332. MTBF is a basic measure of a system's reliability. The higher the time between failure, the more reliable the product.
Different countries have different standards for power supply products. The common standards are as follows:
DoE (USA), CEC (California), NRCan (Canada), ErP (EU), CECP (China), Energy star (USA), 80Plus (USA), CoC (EU), MEPS (New Zealand, Australia, Korea), etc.
It is important to note that power supplies may be required to meet additional energy efficiency standards depending on the customer's application.
Typically, de-rating is when components are deliberately operated at less than a maximum working load to prolong their lives. For example: operation below the maximum power rating, current rating, voltage rating, or temperature rating. This measure enhances product stability and reliability.
In general, companies formulate their own de-rating standards that enable R&D personnel to select appropriate components in the product design stage to reduce their stress.
Longer or thinner output wires usually have poorer voltage regulation and conversion efficiency due to the increased resistance of the outlet, resulting in increased wire loss.
The result of this condition is a relatively low output voltage and efficiency. Therefore, under acceptable conditions, the length of output wires should be reduced or the diameter increased as much as possible.
W(real power)=VA(apparent power)*PF(power factor). Simply put, the larger the PF, the smaller the useless reactive power (apparent power). It means that the power company can reduce electricity generation to achieve the effect of energy conservation and carbon reduction.
On the contrary, smaller PF causes the loss of power supply equipment and transmission lines, further affecting the quality of the power supply. Based on this, international energy efficiency standards have set minimum PFs, such as 8-Plus.
Highly Accelerated Life Testing (HALT) is a testing technique that applies stepped stress to a sample to obtain operational limits and structural strength limits until failure. The goal of HALT is not to estimate the life of the product, but to quickly discover the potential defects in the design stage. With improvement and verification, extreme value of the product is increased, further enhancing its reliability. The stresses applied to the test include vibration, high and low temperature, and temperature shock.
The life data of the electrolytic capacitor of the product is calculated under a given ambient temperature and load conditions. This data is a reference value. Its source is the life calculation formula published by each brand.
Power de-rating reduces the load of a power supply product to meet temperature specification when it exceeds the specified temperature. Power de-rating ensures the reliability of the product and its power supply during high temperature operation.
Power supply products for PCs have their respective fan speed and noise values for different loads. A curve is drawn to provide information to ensure their noise value or fan speed meet their needs.