1. The rated voltage of the selected fuse should be greater than the input voltage of the protected circuit. 2. The rated current of UL specification fuses is determined under laboratory conditions and should be less than 75% of the nominal value during actual use. 3. The rated current of IEC standard fuse tubes can be used at 90% or 100% of the nominal value in actual use. 4. The working life of fuses varies under different operating temperatures. The higher the temperature, the shorter the working life of the fuse; When selecting fuses in practice, it is necessary to refer to the working environment temperature for selection 5. The breaking capacity of a fuse tube is directly proportional to its volume and inversely proportional to the rated voltage. 6. Under more than 100000 pulse impacts, the pulse I2T of the protection circuit should be less than 20% of the rated I2T of the fuse tube.
After the fuse ages, there is no danger of generating the current that should be cut off and the fuse not blowing. The aging of a fuse is equivalent to a decrease in the rated value (current) rather than an increase, resulting in the circuit being cut off at a small overload current or pulse. The durability test in the IEC standard is the life test, which is conducted using a DC power supply at normal temperature: a. Measure the voltage drop until the temperature stabilizes; b. 1.2 times the rated current for 1 hour and cut off the current for 15 minutes. Cycle 100 times; c. Measure the voltage drop after powering on for 1.5 In for 1 hour; d. Measure the voltage drop using the same method as A. Requirement: The voltage drop change before and after the test should not exceed 10%, and the identification should still be clear and distinguishable. There should be no deterioration in the end cap solder joints.
1. Factors that affect the lifespan of fuses: Working environment temperature: Excessive ambient temperature can damage the lifespan of the fuse. Delay type (slow melting type) fuses, such as tin ball type, begin to diffuse towards the metal wire when the temperature is about (150-170 ℃); The temperature at which the fusible metal wire of a quick fuse begins to undergo severe oxidation is approximately (175-225 ℃). Therefore, it is recommended that the delay type fuse fuse should not work above 150 ℃ for a long time, and the fast melting type fuse should not work above 175~225 ℃ for a long time. Pulse current: Continuous pulse impact can generate thermal cycling, leading to diffusion, oxidation, thermal stress, and even acceleration of the fuse. The fuse will gradually age with increasing pulse energy and frequency. Normally, it should be less than 20% to ensure that the fuse can withstand more than 100000 impacts. Other: For example, the length and cross-sectional area of t
A circuit is composed of wires and electronic components, and the parameters of SMD fuses required by different circuits vary. The main parameters of SMD inductors include inductance, allowable deviation, distributed capacitance, rated current, and quality factor. 1. The magnitude of inductance mainly depends on the number of turns (turns) of the inductance coil, the winding method, the presence or absence of a magnetic core, and the material of the magnetic core. Usually, the more coils there are, the denser the wound coils, and the greater the inductance. A coil with a magnetic core has a greater inductance than a coil without a magnetic core. The higher the permeability of the magnetic core, the greater the inductance. So there are many factors that determine the magnitude of inductance. The basic unit of inductance is Henry, denoted by the letter "H". Commonly used units include milliohms (mH) and microohms( μ H) The relationship between them is: 1H=1000mH; 1mH=1000 μ H2. The a
In today's rapidly developing science and technology, fuses are applied in all aspects of people, and the correct selection of fuses is related to the personal and property safety of users! How to choose a fuse correctly? 1. When choosing a fuse, you first need to consider the safety certification of the fuse used in your product. Then, choose its shape and size, rated voltage (usually 250V), and breaking capacity (fast or slow fuse), so that you can preliminarily choose a model. 2. Then select the upper limit and lower limit of the rated current of the fuse based on your circuit, so that you can determine the specific model and current, 3. Then select the fuse for testing and choose the most suitable one. Fuses, also known as fuses, are made of alloys with low melting points. When an overload or short circuit fault occurs in household electrical equipment, the current of the circuit increases, causing the fuse to quickly heat up to the melting point and melt, and timely disconn
Which is the best choice for Shenzhen's self recovery fuses with a wide variety of models and a complete range? The selection of self restoring fuses has always been a classic topic in the electronics industry. On the way to PTC selection, there is always a model that belongs to you, accompanied by the "Six Steps" of ensuring power supply: 1) Determine parameters: standard working current, maximum working voltage, maximum fault current, and maximum working environment temperature; 2) Determine the PTC that can adapt to the maximum working environment temperature and standard working current using a temperature reduction table; 3) Use the electrical characteristic table to verify the maximum electrical rating of the self recovery fuse selected in step 2 and compare it with the maximum working voltage and fault current of the circuit; 4) Determining the action time: In order to provide better protection effect for the circuit, it is crucial to clarify the working time of PTC; 5)
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
