What are the advantages of replacing springs with high-current thimbles in car chargers?

　　With the rising trend of USB PD, car chargers that support 100W output emerge in an endless stream. Through the dismantling of various car chargers through the charging head network, most of these car chargers use high-current thimbles instead of traditional positive springs. So what are the benefits of using a high-current thimble instead of a spring? It can make many manufacturers abandon the use of spring positive electrodes, and the high-current thimble must have many advantages, so that manufacturers can use it invariably.

　　Because the high-power car charger has a built-in buck-boost circuit, there are many components, and the design is more complicated. The internal welding is usually composed of multiple PCBs. Using a small board to solder the thimble can, on the one hand, play a role in fixing and supporting the structure of the internal circuit board. On the other hand, the heat generated by the positive thimble when a large current flows can also be dissipated through the PCB to avoid the high temperature affecting the performance of the inner spring of the thimble.

　　The high-current thimble used in the positive electrode of the car charger consists of three parts, which are divided into a solid needle shaft, which provides an elastic spring and a shell needle tube. Put the spring and the needle shaft into the needle tube, and then riveted the top of the needle tube to fix the needle shaft to produce the thimble. Among them, the head of the thimble is solid, and the shell is thick-walled, which has high mechanical strength and current capacity. The current flows directly from the needle shaft and the needle tube in the whole process, and the direct contact does not pass through the spring, which avoids the problem of spring heating and aging.

　　And the high-current thimbles use thick gold plating, which has good contact and wear resistance, thick walls and thick gold plating, and the resistance is very small. In addition, the gold-plated layer will not oxidize at high temperature and has a long service life. It is the preferred positive connection method for high-end high-power car chargers.

　　With the development of time, in just a few years, USB PD has officially popularized 100W fast charging, which has also brought about a huge change in the structure of car chargers. From spring positive, 18W output, to high current thimble positive, 100W output. High-current thimbles have greatly improved the reliability and life of car chargers, and are becoming the mainstream choice for high-end car chargers.

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