What are the commonly used coils?
1. Single-layer coil
Single-layer coil is made of insulated wire wound around a paper tube or bakelite frame. Such as the medium wave antenna coil of a transistor radio.
2. Honeycomb coil
If the plane of the wound coil is not parallel to the rotating plane, but intersects at a certain angle, this coil is called a honeycomb coil. The number of times the wire bends back and forth during one rotation is often called the number of inflection points. The advantages of honeycomb winding are small size, small distributed capacitance, and large inductance. Honeycomb coils are all wound using honeycomb winding machines. The more inflection points, the smaller the distributed capacitance.
3. Ferrite core and iron powder core coils
The inductance of the coil is related to whether there is a magnetic core. Inserting a ferrite core into an air-core coil can increase the inductance and improve the quality factor of the coil.
4. Copper core coil
Copper core coils are widely used in the ultra-short wave range. The position of the rotating copper core in the coil is used to change the inductance. This adjustment is more convenient and durable.
5. Color-coded inductors
Color-coded inductors are inductors with fixed inductance. Their inductance is marked with color rings in the same way as resistors.
6. Chokes
The coil that limits the passage of alternating current is called a choke, which is divided into high-frequency chokes and low-frequency chokes.
7. Deflection coils
The deflection coil is the load of the output stage of the TV scanning circuit. The deflection coils require: high deflection sensitivity, uniform magnetic field, high Q value, small size, and low price.
