Coils can be classified into 4 different tapes based on different standard.

1. Inductive form: Fixed inductance,Variable inductance
2. Magnetism structure: air coil,ferrit coil, iron Core coil,copper core coil
3. Working condition: Antenna coil, Oscillation coil, Choke coil, Notch coil, Deflection coil
4. Winding structure: Single-layer coil,Multi – layer coil, Honeycomb coil, Close wound coil, Inter – winding coil, Conduction coil,etc.

Common coils in our dairy life.

1 Single-layer coil,

Single-layer coil is wrapped wire around the paper tube or bakelite turns and turns. Such as transistor radios and medium wave coils

2 Honeycomb coil

If the winding coil, the plane is not parallel to the rotation surface, but intersect at a certain angle, this kind of coil is called the honeycomb coil. The number of rotation turns often referred to as the number of folding points.

The advantages of  Honeycomb is small size, small distributed capacitance, and big inductance. Honeycomb-type coiles are winded by honeycomb winding machine, the more points break, the smaller the distributed capacitance

3.Ferrit core coil

The size of the coil inductance has an effects on whether the core. If we Insert the ferrite core in the air core coil,it  can increase the inductance and improve the coil quality.

4.Choke coil

Limit the alternating current through the coil can be called choke ring,.it can be classified into sub-high frequency choke coil and low frequency choke coil.

5. Deflection coil

Deflection coil is a TV scan circuit output stage load. The requirement of deflection coil: high deflection sensitivity, uniform magnetic field, Q value is high, small size, low price.