Operation principle and circuit problems of fuse holder
May 31, 2022
How does the fuse holder work? Next, let's understand the operation principle of the fuse and the problem of circuit voltage.
1. The working principle of the fuse
Many electrical devices in a car circuit are connected by wires of different colors. It cannot be ignored that the role of fuses and fuses is to protect circuits (lines) and electrical equipment. A car fuse is a current fuse. When the circuit current exceeds twice the rated current of the fuse, it will fuse within a few seconds to protect the circuit. Commonly used in automotive circuit overcurrent protection and industrial equipment overcurrent protection.
2. What is a car fuse?
Fuse is our usual name and its official name is fuse. The use of car fuses is similar to that of household fuses. When the circuit current is normal and exceeds its rated current, the fuse becomes a circuit protection barrier. Automotive fuses are roughly divided into two types: fast-acting fuses and anti-melting fuses. Commonly used fuses in automobiles include high current fuses and medium and low current fuses. Common accessible fuses are low and medium current fuses.
Medium and low current fuses can be roughly divided into chip fuses (including automatic fuse boxes), plug-in fuses, swirl fuses, and tubular fuse boxes. Available in these fuses are medium ATO or small fast-acting fuses.
Chip fuses can withstand small currents, short pulse currents, such as headlight circuits, rear glass frost, etc. The working principle of vehicle fuses, fuses have two important working parameters. One is rated current and the other is rated voltage. When using, the corresponding fuse should be selected according to the circuit current and voltage. Structurally, the general car fuse adopts a plug-in design, and the fuse has an engineering plastic shell, a zinc or copper melt structure, a metal melt and a pin connection. The performance index of the car plug fuse is generally 2A~40A, and the fusing value will be marked on the top of the fuse. If the fuse is blown and the amperage value cannot be identified, it can also be judged by its color.
The international standard for the color of the fuse on the car board: 2A gray, 3A purple, 4A red, 5A orange, 7.5A brown, 10A red, 15A blue, 20A yellow, 25A transparent and colorless, 30A green and 40A dark orange. The magnitude of the different amperage depends on the color, which depends on the color. Because the vehicle has many parts and electronic devices, and each device has a fuse, for the convenience of future maintenance work, the designer will design all the car fuses in one place, called a safe, at the beginning of the design of each car. Usually a car has two safes, one is the dry engine compartment, which handles the fuses for the car's external electrical appliances, such as the engine controller, horn, glass washer, ABS, headlights, etc.: the other is on the left side of the driver , Manage the electrical equipment in the car, such as the lifting device on the window, airbags, electric seats, hoods and so on.
3. Circuit safety and rated voltage
During the use of the current fuse type fuse, when the current passes through the conductor, there will be a certain resistance between them, so that the conductor will heat up, and the heat generated by the current fuse holder must be consistent with Q=024T2RT. In this formula, when current flows through the conductor, the body is charged, with 0.24 being the constant and 0 being the heat.
When energized, the heat generated by the fuse of the current fuse holder by the dry current, the current in the normal operating current or the load overload current, and the heat generated by the fuse will cause the fuse temperature to rise. The thermal holes generated by the external radiation method and the external radiation method gradually reach equilibrium.
During the melting process, the melting rate cannot keep up with the melting rate, so that the melting temperature gradually increases, so that the melting temperature reaches and exceeds the melting point of the molten material. Then cut off the current to carry out safety maintenance on the circuit and the human body.
When a current fuse is used, the electrical function of the current fuse holder is connected in series with the electronic circuit. Generally speaking, the resistance is small. Under normal working conditions, it is only equivalent to a wire and can be stable for a long time. Under the power supply or external interference, when the current oscillates, the conduction circuit should also bear a certain overload range. In the current fuse holder, when the circuit has a large overload current, the fuse can work normally and maintain the current to ensure the safety of the circuit.
In daily use, the current fuse holder is very inconspicuous, but if there is no fuse, the vehicle will become a pile of iron blocks without a soul, mainly because light bulbs, car electric starters, air conditioners, and speakers are all fuse protection devices. Otherwise, once the high wire CLP, there is a possibility of using electric scalding.
The current fuse holder has two important parameters, one is the rated current, and the other is the rated voltage. When used, the corresponding fuse must be selected according to the current and voltage of the fuse. Vehicle fuses are divided into high and medium and low fuses. The medium and low current fuses commonly used in ordinary automobiles are medium and low voltage fuses. Commonly used contacts are medium and small rapid fusion plug fuses.
Vehicle fuse holders are relatively common. Generally, vehicle medium and low voltage fuses are divided into insert fuses, bifurcated fuses, spiral fuses, and tubular fuses. Commonly used contacts are medium and small rapid fusion plug fuses.
The corresponding electronics in a car fuse holder are very simple. Typically, the example diagrams inside the fuse box represent the electronics responsible for each fuse. When used, the corresponding location can only be found by matching the diagram to the fuse.
The above is the introduction of "Fuse Holder Operation Principle and Circuit Problems". If you need to know more about the fuse holder, please contact our manufacturer.