What is an air-core coil? 
The air-core coil is composed of two parts, namely a hollow heel coil. Hollow as the name suggests the center is nothing, the coil is the guide wire one by one, the wires are insulated from each other, when the current flows through the wire, a magnetic field can occur around the coil, the strength of the magnetic field and the strength of the current flowing through the coil and the coil The number of turns is proportional.
In the same magnetic field, the coil is used to cut the magnetic line, and the same magnetic field can be converted into electric energy. The magnetoelectric conversion principle can be used to make relays, motors, motors, wireless devices, speakers and other equipment. The wire data can be copper, iron, aluminum, gold and other metal equipment. The center of the coil can be inserted into the metal magnetic device to enhance the magnetic field generated by the conductive flow. When the center of the coil is only a plastic skeleton or no skeleton, an air-core coil is formed. The coils are widely used, and they are designed to be round, square, elliptical, and various shaped shapes for various needs.
Air core coil manufacturing
In the early stage of the circuit test, if you need to go to the air-core coil, you can find the coil manufacturer to order, or you can make an air-core coil. The manufacture of the air-core coil is relatively simple. The electrical performance depends mainly on the inner diameter, the number of turns, and the daytime. Density, as well as the diameter of the wire, the diameter of the wire is mainly affecting the overcurrent element is larger, and the influence value is smaller. The inner diameter is large, the number of turns is large, and the density between the turns is dense, the sense value will be large, and vice versa. The specific sense value can be determined by the instrument test. Before manufacturing, prepare the materials: wire, center skeleton.
The wire can be made of enamelled copper wire. 
The lacquered copper wire sheath has an insulating layer. It is not short-circuited when manufactured together, and the copper wire is an excellent conductive metal material, which is the preferred material for the air-core coil. The center skeleton can find the drill bit. Since the drill bit has large and small specifications, it is convenient to purchase. After the information is prepared, the copper wire is directly wrapped around the smooth end of the drill bit. After winding it, it is taken out from the drill bit and becomes an air-core coil. After winding, it is made of enamelled copper wire. The copper wire can't be directly tinned, and the part of the blade that is about to be tinned is scraped off the outer layer of the paint and then applied to the tin.