What Is an Air Core Inductor?
Air core inductors are mainly used in inductive reception, focusing, magnetic cards, magnetic heads, high current coils, low voltage appliances, industrial control, household appliances, automotive electronics, SMT placement, mobile phones, wireless transceivers, electronic navigators, power regulators, amplifiers , Suppliers and filters.
Air core inductor
- Chinese name
- Air core inductor
- Function
- Blocking, tuning, frequency selection
- Application
- Induction receiving, focusing, magnetic card, magnetic head, etc.
- Air core inductors are mainly used in inductive reception, focusing, magnetic cards, magnetic heads, high current coils, low voltage appliances, industrial control, household appliances, automotive electronics, SMT placement, mobile phones, wireless transceivers, electronic navigators, power regulators, amplifiers , Suppliers and filters.
1. Air-core inductive current blocking effect The self-inductive electromotive force in air-core inductors is always resistant to changes in current in the coils. The air-core inductor has a blocking effect on the AC current. The magnitude of the blocking effect is called the inductive reactance xl, and the unit is ohm. Its relationship with the inductance l and the alternating current frequency f is xl = 2fl.
- 2. Tuning and frequency selection Air-core inductor and capacitor can be connected in parallel to form an lc tuning circuit. That is, the natural oscillation frequency f0 of the circuit is equal to the frequency f of the non-AC signal, so the inductive and capacitive reactances of the loop are also equal, so the electromagnetic energy oscillates back and forth in the inductance and capacitance, which is the resonance phenomenon of the lc loop. At resonance, the equivalent inductance and capacitive reactance of the circuit are reversed, the total inductive reactance of the loop current is the smallest, and the current is the largest (refer to the AC signal of f = "f0"). The lc resonant circuit has the function of selecting the frequency, An AC signal of a frequency f is selected.
1. Inductance L is an inherent characteristic of the coil itself and has nothing to do with the current. Inductance is usually labeled with a specific name.
2. The magnitude of the inductive coil's resistance to AC current is called inductive reactance XL, and the unit is ohm.
3. Quality factor The quality factor Q is a physical quantity representing the quality of the coil, Q is the ratio of the inductive reactance XL and its equivalent resistance, that is: Q = XL / R.
The higher the Q of the coil, the smaller the loss of the loop. The Q value of the coil is related to the DC resistance of the wire, the dielectric loss of the skeleton, the loss caused by the shielding cover or the iron core, and the influence of high-frequency skin effects. The Q value of the coil is usually tens to hundreds.
4. The capacitance between the turns and turns of the distributed capacitance coil, the coil and the bottom plate, and the coil and the shield are called distributed capacitance. The presence of distributed capacitance reduces the Q value of the coil and worsens the stability, so the smaller the distributed capacitance of the coil, the better.
Air core inductors are mainly used in inductive reception, focusing, magnetic cards, magnetic heads, high current coils, low voltage appliances, industrial control, household appliances, automotive electronics, SMT placement, mobile phones, wireless transceivers, electronic navigators, power regulators, amplifiers , Suppliers and filters.
The electronic component mounting board in any electronic equipment is carefully designed, comprehensively arranged and reasonably designed by engineering and technical personnel according to the performance characteristics of various components used. As an installer of air-core inductors, pay attention to the following issues.
(1) The installation position of the air-core inductor should comply with the design requirements. The assembly position of the air-core inductor and the relative positions of other various components must meet the design requirements, otherwise the normal operation of the whole machine will be affected. For example, the position of the high-frequency choke coil and magnetic antenna in a simple semiconductor radio should be properly arranged and reasonable; the antenna air-core inductance and the oscillating air-core electrical induction are perpendicular to each other, which avoids the influence of mutual coupling.
(2) Before installing the air-core inductor, check the appearance of the air-core inductor before using it. Check whether the structure of the air-core inductor is firm, whether the turns are loose and loose, whether the lead contacts are loose, and whether the magnetic core rotates flexibly. No slippers, etc. After all these aspects have been checked, the installation can be performed.
(3) If the core inductor needs to be fine-tuned during use, fine-tuning methods should be considered. Some core-core inductors need to be fine-tuned during use. It is inconvenient to change the number of air-core inductors. Methods. For example, the single-layer air-core inductor can be moved by removing the number of air-core inductors that are near the end point, that is, winding one end of the air-core inductor 3 to 4 times in advance. When fine-tuning, moving its position can change the inductance. Practice has proved that this adjustment method can achieve a fine adjustment of ± 2%-± 3% of the inductance. For air-core inductors used in short-wave and ultra-short-wave circuits, half a turn is often reserved for fine-tuning, and the half-turn is removed or folded to change the inductance and achieve fine-tuning. The fine-tuning of the multi-layer segmented air core inductor can be achieved by moving the relative distance of one segment. The number of turns of the movable segment should be 20% -30% of the total number of turns. Practice has proved that this fine-tuning range can reach 10% -15%. The air core inductor with magnetic core can realize the fine adjustment of the air core inductance by adjusting the position of the magnetic core in the air core inductor.
(4) Use air-core electric induction. Keep the inductance of the original air-core inductor. In use, do not change the shape of the air-core inductor. Size and the distance between the air core inductor, otherwise it will affect the original inductance of the air core inductor. In particular, the higher the frequency, the smaller the number of turns of the air-core inductor. Therefore, high-frequency air-core inductors currently used in televisions are generally sealed and fixed with high-frequency wax or other dielectric materials. In addition, it should be noted that during maintenance, do not change or adjust the position of the original air core inductor at will, so as to avoid detuning failure.
(5) The installation of adjustable air-core inductors should be easy to adjust. The adjustable air-core inductors are installed at the easy-to-adjust position of the machine, so as to adjust the inductance of air-core inductors to achieve the best working condition.