Magnetic ring inductors are one of the simplest products in custom magnetic devices. Many manufacturers often ignore when designing, but there are many pits in the actual process and design of magnetic ring inductors.
Therefore, the standard process design specifications, it is particularly important. This article is divided into two parts: design and technology, this article mainly introduces the design related content.
1. In the design of common mode inductors, the use of 15K material high conductivity core should be avoided to prevent the induction stability from deteriorating when introducing low-cost core suppliers.
2. Amorphous nanocrystalline magnetic ring, need to have a shell, to prevent damage to the magnetic core due to external influence during the winding process.
3. The magnetic ring must be coated; If not, the wire insulation film thickness should be greater than 0.08mm, or the shell design should be used to prevent short circuit caused by damage to the paint film.
4. When using the powder core magnetic ring as the filter inductor, the inductance and current characteristics of the powder core material should be considered to ensure that the inductance attenuation of the current current meets the design requirements. It is necessary to specify the inductance requirement of saturated current to prevent the poor performance of the whole machine.
5. For the magnetic ring of high conductivity material, it is necessary to use a wire with a diameter of less than (including or equal to) 1.2mm, or a directional film or buffer tape outside the magnetic ring, or a shell design to prevent poor inductance caused by stress.
For wire diameters above 6.0.8mm, PEW wire peeling and tinning should be preferred to prevent direct welding from high temperature tinning, resulting in poor pressure resistance.
7. For products with wire diameter less than (or equal to) 0.45mm, the wire cannot be directly used as the PIN pin, and the base needs to be installed. Prevent the wire diameter is too thin, the pin deformation or fracture, the customer can not install.
8. The wire wound on the magnetic core must have good insulation to ensure that no breakdown short circuit occurs between turns of the coil under the action of instantaneous overvoltage. Magnetic ring inductance multi-coil, preferably 1UEW(1UEW-NY) or PEW, AIW and other peeling enameled wire design.
9. In terms of three-layer insulated wire, it is necessary to add casing, preferably direct welding three-layer insulated wire.
10. For the design of the number of magnetic coils, it is necessary to ensure good mass production, and the hand winding should not exceed 30Ts as far as possible, and it is best to meet the requirements of the machine winding.
11. In the design of the number of turns of the magnetic ring, the minimum inner diameter should be reserved to ensure that the last circle of wire can be smooth without scraping each other through to prevent short circuit caused by the damage of the paint film. Part of the magnetic ring reference winding number is as follows:
12. When the safety creepage distance is required between different windings of the common mode inductor, the design must reserve space for installing the isolation baffle to avoid insufficient space and damage to the enameling wire film and prevent poor performance. According to the IEC60950 standard, the common creepage distance requirements are as follows:
13. Coil number design, coil should be wound as much as possible to a single layer, reduce the parasitic capacitance of the coil, in order to enhance the stability of the circuit.