1. Determine the following parameters of the circuit: ● Maximum working environment temperature ● Standard operating current Maximum operating voltage (maximum) Maximum fault current (Imax) 2. Choose a resettable fuse that can adapt to the highest ambient temperature and standard operating current of the circuit. Use the table below and select the temperature that best matches the highest ambient temperature of the circuit. Browse this column to find values equal to or greater than the standard operating current of the circuit. 3. Compare the maximum electrical rating of the selected component with the maximum operating voltage and fault current of the circuit. Use electrical characteristics to verify whether the components selected in step 2 will use the maximum operating voltage and fault current of the circuit. Check the maximum operating voltage and maximum fault current of the equipment. Ensure that Umax and Imax are greater than or equal to the maximum operating vo
Self healing fuse (PPTC) is a very important electronic component widely used in the protection of USB interfaces. It has the characteristics of automatic protection and automatic recovery. When the current exceeds the set value, the circuit will be immediately cut off, and when the current returns to the normal range, the path will be automatically restored. This self-healing fuse plays a crucial role in USB protection. PPTC is a special type of polymer thermistor with a structure similar to a thin wire. When current passes through, the conductive material inside the filament heats up, causing the polymer to expand and block the current path. This blocking effect can effectively cut off the circuit and prevent safety accidents such as fires and short circuits caused by current overload. When current overload or short circuit occurs, PPTC will immediately sense the abnormal situation and automatically cut off the circuit. This is because the material of PPTC has a negative temper
The material of a fuse has a decisive impact on its performance. Based on the search results, we can obtain the following information: Fuses are generally made of silver copper alloy with high resistivity and low melting point. This alloy has good conductivity and melting characteristics, which can quickly melt when the current is too high, thus protecting the circuit. Early fuses were often made of lead antimony alloy, but due to safety reasons, this material has been phased out. When choosing fuse materials, factors to consider include melting point, resistivity, conductivity, mechanical strength, and corrosion resistance. Different application scenarios may require different types of fuses, so the requirements for materials may also vary. In summary, modern fuses are mainly made of silver copper alloy and no longer use lead antimony alloy. When selecting fuse materials, multiple factors should be considered comprehensively to ensure their reliability and safety in specific en
This is very simple. As long as you know the meaning represented by the parameters in the specification book, you can clearly and quickly view the PTC specification book for self recovery fuses. 1. IH (Holding Current): The maximum current that can pass through a polymer thermistor PTC in a static air environment at 25 ℃ when it remains inactive. Under limited environmental conditions, the device can maintain an infinite amount of time without transitioning from a low resistance state to a high resistance state. (If the current passing through PTC is insufficient to cause the PTC to self heat up beyond the Curie temperature, such current is called the non operating current, and the maximum value of the non operating current is called the maximum non operating current) 2. IT (operating current): The minimum steady-state current at which the polymer thermistor PTC operates within a limited time in a static air environment at 25 ℃. 3. Vmax maximum voltage (withstand voltage value):
Compared with NiMH or NICd batteries, lithium-ion batteries have a higher current density and are widely used in various portable devices. Lithium ion batteries are usually very sensitive to overcharging. When the voltage at both ends of the battery is too high during charging, it will increase battery leakage The danger of smoking, burning, and bursting (which is often quite severe). Overcharging may be caused by uncontrolled charging, electrode errors, or Caused by using an incorrect charger. When the charging and discharging current of lithium-ion batteries is too high or there is an external short circuit, internal heating may damage the battery or burn other components, seriously shortening the battery's cycle life. The task of protecting the circuit is to monitor the parameters of the battery's charging and discharging status in response to various possible faults, in order to ensure battery life and efficiency, and to prevent damage to the battery and external devices su
The working principle of a resettable fuse is the dynamic balance of energy. The current flowing through the resettable fuse generates a certain degree of heat due to the thermal effect of the current (there is a resistance value in the resettable fuse). All or part of the heat generated is dissipated into the environment, but the remaining heat will increase the temperature of the resettable fuse element. During normal operation, the temperature is low and the heat generated and dissipated reaches equilibrium. When the resettable fuse is in a low resistance state, it does not work. When the current flowing through it increases or the ambient temperature rises, if the generated and dissipated heat reaches equilibrium, the fuse will remain inactive. If the current or temperature continues to rise at this time, the heat generated will be greater than the heat dissipation, causing a sharp increase in the temperature of the resettable fuse. Therefore, small temperature changes will l
MB:+86 13924633629 Ms.vicky
E-mail: waimao@xcfuse.com
Factory :
XC Electronics(Shenzhen)Corp.,LTD
Add: Jinyuan Industrial zone,Heao, Henggang, Shenzhen 518115,China
Shenzhen branch: Shenzhen Xucheng Electronic Commerce co.Ltd
Add: 8-15 Jinyuan Industrial zone,Heao, Henggang, Shenzhen 518115,China
