Leading Choke Coil Manufacturers

What Is a Choke Coil?

A choke coil usually has a coil of insulated wire wound on a magnetic core. Other chokes contain a bead of donut-shaped ferrite material strung on a wire. The impedance of the choke increases with the frequency. Its low electrical resistance passes direct current and alternating current with little power loss, although its reactance limits the amount of alternating current passed.

How Choke Coils Function

The main idea in sending the signal through a circuit is to let the wanted signal go through while simultaneously filtering out the unwanted signals. The choke coil is the best fit because it works as an inductor. When the current passes through changes, as the alternating current does, it creates a magnetic field in that coil that works against the current. This property is known as inductance and blocks almost all the alternating current from passing through.

Currents such as direct currents, which do not change, can continue through, while those that do change are blocked by the magnetic field they would have created on their own. A material used to produce a magnetic field is at the core of this part. An air core or a ferrite core can be used in coils that filter higher frequencies, while an iron core can be used for those that filter low frequencies. The coil's rate of inductance and the magnetic field's strength are determined by the material used in the core. A choke coil keeps the electric charge in the magnetic field created around it.

Types of Choke Coils

Choke coils are grouped according to their application areas, ratings in inductance, voltage rating, and design.

Audio Frequency Choke Coil

This type of choke coil usually has ferromagnetic cores, which help to increase their inductance. They are usually constructed in a way similar to that of transformers, with laminated iron cores and an air gap. The iron core does the work of increasing the inductance for a given volume of the core. Choke coils were usually used in rectifier power supplies for vacuum tube equipment, including radio receivers or amplifiers.

Chokes are commonly found in direct current motor controllers to produce direct current. They were used in collaboration with large electrolytic capacitors to remove the voltage ripple at the output DC. A rectifier circuit designed for a choke output filter may produce a lot of DC output voltage and expose the rectifier and the filter capacitors to excessive in-rush and ripple currents if the conductor is removed.

Radio Frequency Choke Coil

These audio frequency chokes usually contain iron powder or ferrite cores, which help increment the inductance and overall operation. They are usually wound in complex patterns to reduce self-capacitance and losses of proximity effect.

Choke coils for even higher frequencies have low inductance and non-magnetic cores. The ferrite bead is an example of a modern choke used to eliminate digital RF noise from lines. These are often seen on computer cables, and an RF choke value can be 2 mill henries.

Common Mode Choke Coil

This type of choke coil has a case where two coils are wound on a single core. It is useful for compression of electromagnetic interference and radio frequency interference from power supply lines and also for preventing the malfunction of power electronic devices. The choke passes differential currents at the same time blocking common mode currents.

The differential mode currents produce a magnetic flux, which tends to cancel out since the windings are negatively coupled. Therefore, the chokes result in nominal impedance of inductance to DM currents, whereas CM currents are presented at high impedance because of the combined inductance of the positive coupled windings.

Applications and Uses

Choke coils are used for the reduction of electromagnetic interference in electronic circuits. High voltage at the starting time can be produced as choke coils are used with fluorescent tube light. To reduce noise and other interferences, choke coils are used in conjunction with sensitive cables and connectors such as USB data cables and HDMI cables. Audio frequency choke coils are used in subwoofers and other audio systems. These choke coils are also used in power supply circuits such as inverter circuits, voltage regulators, and rectifier circuits.

Choosing the Proper Choke Coil Supplier

To ensure you have the most positive outcome when purchasing choke coils from a choke coil supplier, it is important to compare several companies using our directory of choke coil suppliers. Each choke coil company has a business profile page illustrating their areas of experience and capabilities, along with a contact form to directly communicate with them for more information or request a quote. Review each choke coil company website using our patented website previewer for a better idea of what each business specializes in. Then, use our simple RFQ form to contact multiple companies with the same form.