1. The application of self recovery fuse in rechargeable battery pack 1) Problem and Analysis: NICD, NiMH, and Li-ION are commonly used in special protection circuits for mobile phones and computers. The reasons for these battery pack failures are usually: unexpected short circuit between the positive and negative terminals; The charger cannot stop charging a fully charged battery; The polarity of the wrong charger or battery is reversed. Installing the PTC patch series in series in various units of the battery pack can provide overcurrent and over temperature protection for the circuit. 2) Protection requirements: In the event of a malfunction, the voltage of the mobile phone can reach 16V, and the voltage of the computer can reach 24V; Its current can reach 100 amperes. In overcharging conditions, the battery pack needs to be protected against overheating. NiCD batteries cannot exceed 120C, and NiMH and Li Ion batteries cannot exceed 90C. The ultra small package (0402 specific
Normal current flow: It is important for everyone to understand the normal current flow through the patch fuse in the circuit being used. Generally speaking, everyone needs to set a derating amount in advance, and then select according to the following basic principle: the normal current amount must be lower than the product of the rated current and the derating coefficient. Fusing current: According to UL specifications and models, patch fuses should quickly fuse at twice the rated current. But in most cases, in order to ensure stable fusing, we suggest that the fusing current should be greater than 2.5 times the rated current. In addition, when the time of the circuit breaker is important, the judgment must also be made by referring to the circuit breaker performance diagram provided by the manufacturer. Open circuit voltage: The open circuit voltage should usually be selected below the rated voltage. For example, when using a chip fuse with a rated voltage of DC24V in an ACl00
The fuse breaking current of the patch fuse is 1.5 to 2.0 times the rated current. When electrical equipment is in normal use, its fuse will not break. When the current in the circuit exceeds 5 times its rated current, it will automatically break to provide protection. If the fuse melts during normal use of electrical equipment, it indicates that the current in the circuit exceeds the rated current. Therefore, the cause should be immediately investigated. During the installation process of patch fuses, it is necessary to first pull off the switch on the distribution board and cut off the power supply. It is better to use an electric pen to test whether there is power before operating. For fixing screws and washers, copper should be used instead of iron temporarily, as iron can easily rust and lead to poor contact over time. When tightening the fuse, do not use excessive force to prevent the fuse from being flattened and causing a reduction in the cross-sectional area, rated curren
Select the type of fuse based on the electrical load characteristics in the circuit (slow melting or fast melting fuse). Fuses can be divided into slow fuse and fast fuse according to their different fusing characteristics. Fast melting fuses are commonly used in resistive circuits to protect components that are particularly sensitive to current fluctuations; Slow melting fuses are commonly used to quickly disconnect circuits when there is a fault with a large surge current when the circuit status changes. Finally, according to the sensitivity/capacitance circuit (such as the fan motor circuit), it can withstand the impact of surge pulses when switching on and off the machine, and the appropriate fuse type of structure is selected for the actual assembly position where the fuse wire appears. Priority should be given to fuses that occupy little space after installation.
To fully utilize the protective effect of a fuse in a circuit, the position of the fuse in the circuit should be considered when designing the circuit. The fuse can be blown in a timely manner to protect the circuit and switch; And the fuse cannot be blown in a timely manner, unable to protect the front-end circuit and switch. If a short circuit occurs at B, the fuse can only be blown in a timely manner, which can protect the circuit; As shown in the circuit diagram, when a short circuit occurs at point A, the switch will still burn out, while the fuse will not blow, meaning that the fuse in this circuit cannot protect the circuit and electrical components. So the circuit diagram is the most reasonable one for designing the position of the fuse in the circuit. Note: For the case where relays and fuses are integrated in the same electrical box, the fuse connection is not closely related (as the possibility of a short circuit occurring within the same electrical box is not high),
A fuse is an electrical component installed in a circuit to ensure safe operation of the circuit. When the circuit malfunctions or is abnormal, it may burn the circuit or even cause a fire. Some fuses have a blown indicator device, which is used to indicate that when the fuse is activated (blown), it undergoes a certain appearance change and is easily detected by maintenance personnel. So what are the components of a fuse? 1. Electrode Usually, there are two important components that are connected between the melt and the circuit. They need to have good conductivity and should not generate significant installation contact resistance. 2. Melt It is the core of a fuse and plays a role in cutting off the current when it is blown. Fuses of the same type and specification should have the same material, geometric dimensions, and resistance values as small and consistent as possible. It is important to have consistent fusing characteristics. 3. Bracket The melt of a fuse is generall
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
