What Is a Common Mode Choke?

Electrical and electronic circuits operate within specific bands of electrical frequencies. Anything outside those frequencies can be considered noise, interfering with electronic devices' proper functionality. A common mode choke is an essential electrical component that filters out unwanted frequencies, also known as electromagnetic interference (EMI), from electronic circuits. These magnetic inductors eliminate or suppress undesirable frequencies, creating a cleaner signal for better device efficiency. Common mode chokes offer extensive benefits, such as enhanced efficiency, low EMI radiation, high inductance, and suppressing or blocking high-frequency signals.

Since 1964, MH&W International Corp. has developed into a leader in the power conversion and EMI filtration technologies sector. The company specializes in innovative components for filter applications and power conversion and is committed to continuous improvement, supplying innovative noise-filtering solutions for wind, solar, EV, and VFD applications. Our experienced team is dedicated to providing quality service to customers and addressing their common mode noise challenges.

Common Mode Noise: What Is It and What Are Its Effects?

Common mode noise is EMI that can occur in electrical circuits. It is a noise signal on both conductors of a balanced circuit concerning ground and can result from various sources, including power lines, switching circuits, and other electronic devices. 
The effects of common mode noise can vary depending on the severity and frequency of the noise signal. Here are some of the common effects of common mode noise:

  1. Signal distortion: Common mode noise can cause signal distortion in electronic circuits, leading to reduced performance and reliability of the system. This can result in errors in data transmission, reduced accuracy in measurement systems, and other issues.
  2. Electromagnetic interference: Common mode noise can generate EMI that can interfere with the operation of other electronic devices and systems. This can lead to crosstalk, data corruption, and other issues.
  3. Malfunctioning of electronic devices: Common mode noise can cause electronic devices to malfunction, leading to system downtime and loss of productivity. This is particularly true for sensitive electronic equipment, such as medical devices or control systems for industrial machinery.
  4. Overheating and component failure: Common mode noise can cause components in electronic circuits to overheat, leading to premature failure. This can result in the need for costly repairs or replacements.

Overall, common mode noise can significantly impact electronic systems' performance and reliability, reducing efficiency and increasing downtime and costs. It is important to address common mode noise issues in electronic circuits to ensure optimal system functionality. This can be achieved through common mode chokes, EMI filters, or other noise suppression techniques.

Benefits of Common Mode Chokes

Common mode chokes are electrical components that suppress common mode noise in electrical circuits. They are also called common mode inductors or simply common mode filters. Some of the benefits of using common mode chokes in electronic circuits include:

  1. Reducing common mode noise: Common mode chokes are designed to reduce common noise in electrical circuits. They can filter out noise signals on both conductors of a balanced circuit concerning ground, thereby reducing EMI and other noise-related issues.
  2. Improving signal quality: By reducing common mode noise, common mode chokes can improve the signal quality of electronic circuits. This can result in better performance, reduced distortion, and improved reliability of electronic devices.
  3. Efficiently using space: Common mode chokes are relatively small, making them an ideal solution for limited-space applications. 

Overall, common mode chokes are an effective way to suppress common mode noise and improve the performance and reliability of the electrical system. They are widely used in various applications, including power supplies, motor drives, communication systems, and more.

Applications of Common Mode Chokes

Common mode chokes are widely used in various electronic applications where it is necessary to reduce common mode noise and improve the performance and reliability of the circuit. Here are some of the applications of common mode chokes:

  1. Power supplies: Common mode chokes are commonly used in power supplies to filter out common mode noise and improve the efficiency and reliability of the system. They can be used in AC/DC power supplies, DC/DC converters, and other types of power electronics.
  2. Motor drives: Common mode chokes are often used in motor drives to reduce EMI and other noise-related issues and prevent bearing failures as a result of EDM. They can be used in AC and DC motor drives, servo drives, and other motor control systems.
  3. Communication systems: Common mode chokes are used in communication systems to suppress noise signals and improve signal quality. They can be used in Ethernet interfaces, telecommunication systems, and other communication equipment.
  4. Audio equipment: Common mode chokes can be used in audio equipment to reduce noise and distortion in the signal path. They are commonly used in preamplifiers, power amplifiers, and other types of audio equipment.
  5. Lighting systems: Common mode chokes are used in lighting systems to reduce electromagnetic interference and improve the system’s performance. They can be used in fluorescent lighting systems, LED lighting systems, and other types of lighting equipment.
  6. Medical equipment: Common mode chokes are used in medical equipment to suppress noise signals and improve the system’s reliability. They can be used in patient monitoring systems, diagnostic equipment, and other types of medical devices.

Overall, common mode chokes are essential in many electrical and electronic systems and are used in a wide range of applications where noise suppression is required.

Industrial-Grade Mode Chokes From MH&W

MH&W International Corporation is a well-known supplier of industrial-grade common mode chokes. Our product line includes common mode chokes with different specifications for various industrial applications. Some of the features of our common mode chokes are:

  1. High-quality materials: MH&W uses high-quality materials in common mode chokes to ensure maximum performance and reliability. We use nanocrystalline materials to provide high magnetic permeability, low losses, and excellent noise suppression.
  2. High current ratings: MH&W common mode chokes are designed to handle high currents, making them ideal for industrial applications requiring high-power levels. Depending on the specific product, they can handle currents ranging from a few milliamperes to several hundred amperes.
  3. Customizable designs: MH&W can provide customized common mode chokes to meet the specific requirements of our customers. We can design and manufacture common mode chokes with specific inductance values, current ratings, and other specifications.
  4. High temperature tolerance: MH&W common mode chokes are designed to operate at high temperatures, making them suitable for industrial applications that generate much heat. 
  5. RoHS compliant: MH&W common mode chokes are RoHS compliant, ensuring that they meet the environmental standards set by the European Union.

MH&W common mode chokes are a reliable, high-performance solution for industrial applications requiring noise suppression and high current handling capabilities. Their customizable designs and high temperature tolerance make them an ideal choice for a wide range of industrial applications.

To learn more, contact us today and talk with our experienced team about your EMI filtration needs.