The life span of the power adapter is the same as the life span of a human being. It is impossible to predict the exact number of years, but many big data analysis reports have the concept of average life span. The same is true for the power supply. There are many factors that affect its life. Therefore, the life of the general power supply is measured by the mean time between failures.
We need to reduce the possibility of failure to ensure long-term stable operation of the power supply. Then we need to control the two important links in the power supply life cycle: power supply research and development, and power supply production. Power supply research and development needs to ensure that the performance of the power supply meets the requirements of our specifications and the power performance indicators during the normal life cycle of the power supply. Power module products have high requirements for production process and process control, and require high-quality production equipment and management to achieve the expected product quality.
The barrel effect is also satisfied between the life of the in-line power adapter and the components used, and the life of all components reaches the specified life to ensure the ultimate life of the power supply. Generally, key components are subject to large electrical stress, high heat generation, and rapid increase in internal temperature of the machine. Temperature has a greater impact on the life of the device, so the final assessment of the life of the device is particularly important. So what are the key components in our power adapter that need special attention?
1. Electrolytic Capacitor
The electrolytic capacitor is a temperature-sensitive device in the power adapter device. From this perspective, the quality of the electrolytic capacitor also determines the life of the power supply device to a certain extent, and the performance of the AC-DC power adapter product is outstanding.
2. Primary switch tube (MOS tube)
Such switching devices are in a high-speed switching state and are subject to high voltage stress and current stress. The heat caused by the switching loss will also accelerate the aging of the device, and it is also susceptible to breakdown and damage due to external high voltage interference.
3. High frequency power transformer
When high-frequency transformers are transmitting energy, internal losses will cause them to generate heat, and the heat radiated will also affect the life of the transformer materials. Common transformer faults include insulation breakdown, winding burnout, and copper wire breakage.
4. Multilayer ceramic capacitors
SMD ceramic capacitors are prone to problems in the solder joints of the capacitors, which may crack due to some stress. In order to minimize the possibility of occurrence, it is recommended to avoid the parallel use of multiple ceramic capacitors.
5. Output rectifier diode
The diode mainly bears two major electrical stresses, including the reverse withstand voltage and the forward current, and the diode is also a heating device. In order to ensure the service life of this device, we will flow out enough margin during the design, and ultimately ensure the batch performance of the power adapter.
6. Optocoupler
The current transfer ratio (CTR) will gradually decrease over time. In order to keep the loop stable, the current of the light-emitting diode will continue to increase and eventually reach its limit value, resulting in damage to the optocoupler.
In summary, the value of the power adapter module is not with the module itself, but with the level of craftsmanship that guarantees batch quality. What consumers need is the safety and reliability of the power adapter, thereby reducing product production and maintenance costs.
