The polymer overcurrent protection element is made by adding conductive particles to the polymer material. Its basic principle is a kind of energy balance: when current flows through the components, due to the current consumption power generate heat, heat generated by the scattered to the environment, part of the increased temperature of polymer materials. In the corresponding working current, the heat generated by the element and the heat emitted are balanced and the current can be passed normally. Sharply when too much current components to generate heat and not to send out in time, results in a polymer materials in the component temperature rise, when the temperature reached the material melt crystallization temperature, the polymer swelling, blocking conductive path composed of conductive particles, rapid rise in resistance (see photo), limits the big electric current passes through, so as to have the effect of over-current protection. When troubleshooting, PTC to cooling crystallization, volume shrinkage, the conductive particles to form a conductive path, since after the fuse for low resistance state, so as to complete the protection of circuit, without artificial replacement.

Large capacity of huizhou city electronic technology co., LTD., specializing in circuit protection components (PPTC, since restoring fuses, current fuses temperature fuse, thermistor) product development, production and sales, is the world a few polymer protective components supplier of core technology.