Self-recovery fuse is a kind of over-current electronic protection component, which is made of high-molecular organic polymer under the conditions of high pressure, high temperature and vulcanization reaction, mixed with conductive particle materials, and processed by a special process. It is customary to call PPTC a resettable fuse.       

The main function of the self-recovery fuse is to do over-current protection in electrical appliances. Therefore, self-recovery fuses have parameters such as withstand voltage, current resistance, maintenance current, and operating time. Therefore, the resettable fuse selection is based on the voltage, current and protection current of the product used to make a suitable resettable fuse selection.       

Methods as below:           

First determine the maximum ambient temperature for the normal working of the protected circuit, the working current in the circuit, the maximum working voltage, the required protection current, the action time and other parameters (related reading: PPTC in the 220V AC lamp touch dimmer circuit)           

2. According to the characteristics of the protected circuit or product, choose whether the applicable self-recovery fuse is a plug-in fuse or a chip fuse.       

 3. According to the maximum working voltage, select the product series with the withstand voltage level greater than or equal to the maximum working voltage        

4. According to the maximum ambient temperature of the circuit and the operating current in the circuit, compare the temperature reduction rate of the self-recovery fuse to select the product specification that is suitable for the maintenance current       

 5. According to the action time curve of the self-recovery fuse of this model, confirm whether the selected product meets the required action protection time.        

6. Check the data provided in the specification to confirm that the size of the thermistor meets the requirements. (Recommended reading: The data collector needs the Chiron (Tianlang) PPTCfuse resettable fuse for lightning protection and overload protection)        

The selection of self-recovery fuse can be selected according to the above 6-step method. However, many of the circuits required to be protected are very complicated, and the specific selection must be carried out according to the specific situation, and the final suitable product must be determined after experimental testing