Quadruple-turn Winding Coil

A four-coil coil is a coil structure composed of four coils. Depending on the application scenarios and functions, its specific structure and working principle may vary. The following are some common four-wire winding coils and their related introductions:

Four-coil air-core coil: Its winding core shaft is usually composed of two first assembly blocks and two second assembly blocks alternately inserted and connected. When winding, first wind the wire on the first assembly block. After completion, take out the first assembly block and push out the first coil. Then wind the wire on the second assembly block, take out the second assembly block again and push out the second coil. Repeat the same process to complete the winding of the third and fourth coils, and finally form four hollow coils. This type of coil can be used in some situations where there are specific requirements for the spatial magnetic field distribution.

Four-coil structure for magnetic resonance wireless charging: In magnetic resonance wireless charging applications, the cylindrical four-coil structure is divided into a transmitting part and a receiving part. The transmitting part includes C1, L1 and La, and the receiving part includes Lb, L2 and C2. The high-frequency input power supply u1 of the transmitting part is connected to the capacitor C1 and the first transmitting coil L1 to form an LC resonant circuit. High-frequency voltage is generated on C1 and L1 through resonance. The high-frequency voltage on L1 is transmitted to the second transmitting coil La through inductive coupling, and electrical energy is emitted by La. The first receiving coil Lb in the receiving section receives electrical energy and transmits it through coupling to the second receiving coil L2. L2 and C2 generate resonance, outputting a high-frequency voltage u2. Compared with the two-coil structure, this structure can perform power supply matching and load matching, achieving isolation of the influence of high-frequency power supply and load on the resonant coil, but its structure is relatively complex.

The four-wire ignition coil of a car is composed of a main coil and a secondary coil. One end of the main coil is connected to the positive terminal of the power supply, and the other end is connected to the switch. One end of the secondary coil is connected to the main coil, and the other end is connected to the spark plug. When the ignition switch is turned on, current flows from the power supply to the main coil. Due to the large number of turns in the main coil, a strong magnetic field is generated. When the current is turned off, the magnetic field changes. According to the law of electromagnetic induction, an induced electromotive force is generated in the secondary coil. Moreover, the secondary coil has fewer turns, and the induced electromotive force is much larger than that of the main coil. When the induced electromotive force reaches a certain value, The voltage is high enough to penetrate the spark plug gap and achieve ignition.

Four-pin inductor coil: It is an electronic component with a certain self-inductance made by winding insulated wires. When current passes through a coil, a magnetic field is generated. As the current increases, the intensity of the magnetic field also increases. However, when the magnetic field within the magnetic conductor of the coil reaches a certain limit, even an increase in current cannot increase the intensity of the magnetic field, that is, it reaches the "magnetic saturation" state. This type of coil is often used in electronic circuits to serve functions such as filtering and energy storage.