An electric choke is an inductor. The characteristic feature of the inductor is its high AC resistance and low DC resistance. The choke, being a protective component in power supplies, filters out high-frequency signals and at the same time protects the supply network from electromagnetic interference. Chokes have also found their application in ballasts designed to run fluorescent lamps, and in many other devices.
- - ferromagnetic core;
- - copper wire;
- - winding machine;
- - screws;
- - nuts;
- - insulating tape;
- - epoxy glue.
First, select the core type of your inductor. Select it of the appropriate size and material, according to the annotation to the circuit diagram of the device where the choke will be used. There are steel, permalloy, iron and ferrite cores. They all have ferromagnetic properties. Their main task is to increase the inductance of the inductor. Buy the core you want from a radio store.
Secondly, in the same place, in radio goods, purchase the wire necessary for winding the choke. It can be copper or aluminum. The material from which the wire should be made, as well as its cross-section and marking, can be found in the description of the circuit diagram. In any case, copper wires have a number of physical and electrical advantages over aluminum ones. Therefore, if possible, purchase a copper wire.
For the core of the inductor, make a cardboard or plastic sleeve. Make it based on the dimensions of the choke core. It is good if the choke contains only a few turns. Then wind the wire around the core sleeve by hand. If the inductor contains hundreds or even thousands of turns, you cannot do without a special machine. Purchase a machine for manual winding of transformers or borrow it from your friends. The machine will allow you to wind the choke coil quickly and smoothly, turn to turn. All machines are equipped with turn counters.
After winding the required number of turns on the sleeve, treat the coil with epoxy. This is necessary to reduce the turn-to-turn capacity and ensure water resistance. Let the resin dry. Lay 2 layers of electrical tape on top of the coil and insert the core into it. If the choke is size and power, tighten the core parts with screws using brackets. This will prevent it from buzzing during operation and will partially dampen the vibration. If the design requires a common wire, connect it to the core. Then, when installing the choke, connect it to the common wire (ground) of the device.