The power supply using a polymer fuse PPTC for overcurrent protection has become the first choice for engineers. Using a chip to control overcurrent for protection is costly, and there are many peripheral components, and it is prone to failure. The polymer fuse device can solve the overcurrent protection function, and the response is sensitive. Once over-current occurs, it will be in a protection state immediately, effectively protecting the charged device, battery, and other key circuits of the mobile power supply itself. And it can be automatically restored, this excellent performance is certainly more and more engineers are. In the circuit, it is enough to meet the overcurrent protection function, the layout and wiring are quite simple, and the production cost is reduced.

The power supply is composed of over-current protection devices, batteries, and over-charge and over-discharge circuits. The previous overcharge and overdischarge circuits used ICs for overcurrent protection. The circuit is complicated, the failure rate is high, and the cost is high. Some users return goods, repairs, and manufacturers are fined for compensation. It makes manufacturers and designers very annoyed, because the above problems must be solved to promote the application. For this reason, the manufacturer has designed many solutions for over-current protection: polymer fuses are used, with fewer components, low failure rate, good functions, and rapid over-current protection. The simplest circuit and the lowest cost solution enables the over-current protection of the mobile power supply to solve the above-mentioned problems.

It turns out that only a self-recovery fuse PPTC component is needed to solve the above problem. Connect the self-recovery fuse in series to the battery output power supply line. As long as the current is too large when the internal or external overcharge or overdischarge occurs, the polymer fuse can be protected in time, and the battery and peripheral equipment will not burn out.
Polymer fuses are also known as self-resetting overcurrent protectors, and there are also 10,000-time fuses. It is a patented product of YAXUN, also called recoverable overcurrent protector or polymer resettable fuse. The resistance value is very low during normal operation and does not affect the operation of the circuit. When the power supply is overcharged or overdischarged, a large current is generated, which causes the polymer fuse to change from low resistance to high resistance, which limits the current of the power supply and achieves the purpose of protecting the power supply and the system. When the power is cut off, the self-recovery fuse returns to a low resistance, and the power supply returns to a normal state. Whether you choose a plug-in polymer fuse or a patch polymer fuse, you can achieve the purpose of timely protection.