EMI Filters & Protection shielding materials offer a wide range of products from leading industry brands such as TDK, Schaffner, TE Connectivity, Wurth Elektronik and Laird Technologies as well as our RS PRO brand for even better value.
Understanding the Importance of EMI Filtering
EMI filters and EMI shielding protection products can be attached to devices or circuits to reduce high-frequency electromagnetic noise transmitted through conduction that may cause interference with other devices. This means that EMI filters can remove any unwanted current conducted through cables and wires but at the same time still permitting other wanted currents to flow. Some countries also have legal requirements that determine the approved type and amount of EMI that devices may generate, so that they do not interfere with other equipment. These regulations can therefore drive the decision to use a filter to keep harmful EMI out of a device.
EMI (electromagnetic interference) is present in all areas of electronics and disrupts electronic operations and electronic devices from emissions. EMI can have a big effect on electronic operations and communications in various industries as EMI travels in waves and can cause devices and equipment to malfunction. In order to reduce the effects of EMI, you can use EMI filters and shielding protection devices that can help remove electromagnetic radiation waves. These filters can also prevent EMI from escaping and interfering with other sensitive equipment close by. High reliable EMI filters and protection shielding products are designed to consistently meet requirements and are essential to many industries and businesses.
Types of EMI Filters and Protection
Effective EMI filtering is necessary for almost every modern electronic device, including devices that generate their own EMI, as well as devices that are sensitive to EMI within their environment. Popular devices include:
Ferrite Beads (also known as ferrite chokes)
Ferrite beads are passive components that suppress high-frequency noise in electronic circuits. They consist of a ferrite core material that exhibits high permeability at high frequencies. When a high-frequency current flows through a wire passing through the bead, the ferrite core generates a magnetic field that opposes the current flow, effectively attenuating the high-frequency noise.
Ferrite Rings and Sleeves
Ferrite rings and sleeves function similarly to ferrite beads, but they are designed to be installed over cables or wires. The ferrite material in the ring or sleeve forms a magnetic circuit around the conductor, suppressing high-frequency noise that travels along the cable.
Common Mode Chokes
Common mode chokes are specialised inductors designed to suppress common-mode noise, a type of EMI that affects both conductors of a differential pair equally. They consist of two windings wound on a common core, such that the magnetic fields generated by the two windings cancel each other out for differential-mode signals but add up for common-mode noise. This allows common-mode chokes to effectively suppress common-mode noise without affecting the desired differential-mode signal.
Feedthrough Capacitors
Feedthrough capacitors are used to filter high-frequency noise on cables passing through enclosures or shielded compartments. They consist of a capacitor connected between the cable's inner conductor and the enclosure or shield. The capacitor provides a low-impedance path for high-frequency noise to ground, effectively bypassing the noise around the enclosure and preventing it from entering or exiting.
Power Line Filters
Power line filters are designed to suppress conducted EMI on AC and DC power lines. They typically consist of a combination of capacitors and inductors that filter out high-frequency noise. Power line filters are commonly used in a wide range of electronic devices to protect them from EMI generated by external sources, such as power grids and nearby electronic equipment.
RC Network Capacitors
RC network capacitors are simple filters consisting of a resistor and a capacitor connected in series. They are often used to filter out high-frequency noise on signal lines. The capacitor provides a low-impedance path for high-frequency noise to ground, while the resistor limits the current flow and prevents the capacitor from shorting out the signal.
Shielding Sheets and Strips
Shielding sheets and strips are made of conductive materials, such as copper or aluminium, and are used to create barriers against electromagnetic fields. They can be used to enclose entire devices or individual components to prevent EMI from entering or escaping. Shielding is particularly important for sensitive electronic devices that are susceptible to interference.
Signal Filters
Signal filters are designed to selectively pass or attenuate specific frequencies in a signal. They can be used to remove unwanted noise or interference from a signal or to isolate specific frequency bands for further processing.
Sine Wave Filters
Sine wave filters are specialised filters designed to remove harmonics and other distortions from a sine wave signal. They are commonly used in applications where a clean sine wave is required, such as audio systems and power supplies.
Industrial Applications of EMI Filtering
The significance of EMI filtering reverberates across diverse industrial sectors, where the repercussions of electromagnetic interference can be severe. Let's explore some key applications:
- Industrial Automation: In the heart of factories and manufacturing plants, where sensitive electronic equipment orchestrates complex processes, EMI filtering ensures the smooth and uninterrupted operation of machinery. It prevents malfunctions, safeguards data integrity, and protects worker safety.
- Telecommunications: In the bustling world of communication networks, where vast volumes of data traverse at lightning speeds, EMI filtering is crucial for preserving signal quality and preventing data corruption. It guarantees clear and reliable communication, even in environments saturated with electromagnetic noise.
- Medical Devices: In the realm of healthcare, where the accuracy and dependability of medical equipment are paramount, EMI filtering is a lifeline for patient safety. It prevents interference with sensitive electronic devices, ensuring precise diagnoses and effective treatments.
- Automotive Electronics: In modern vehicles, where electronic systems control everything from engine management to safety features, EMI filtering is vital for ensuring the reliable operation of these critical components. It shields against interference from external sources, such as power lines and radio transmissions.
- ESD & Clean Room: In industries where static electricity can wreak havoc on delicate electronic components, ESD (electrostatic discharge) control measures are imperative. Clean rooms, with their meticulously controlled environments, further minimise the risk of contamination and damage.
How to Choose the Right EMI Filter
Selecting the ideal EMI filter requires careful consideration of several factors:
- Frequency Range: Identify the frequency range of the interference you need to suppress. Different filters are tailored to attenuate specific frequency bands.
- Insertion Loss: Consider the desired level of attenuation. Higher insertion loss values signify greater noise reduction.
- Current Rating: Ensure the filter can handle the anticipated current flow without overheating or compromising performance.
- Size and Mounting: Choose a filter that fits your available space and mounting requirements.
- Environmental Conditions: Consider the operating temperature, humidity, and other environmental factors that the filter will encounter.
Trusted EMI Filters Manufacturer, Supplier & Distributor in Australia
RS stands as your trusted source for EMI filters in Australia. As a leading distributor, we offer an extensive range of high-quality EMI filters from renowned brands like TDK, EPCOS, and Murata. Our team of experts is ready to provide technical support, assisting you in selecting the perfect filter for your specific application.
Buy EMI Filter from RS
Ordering EMI filters from RS is a straightforward process. Browse our extensive online catalogue, select the products you need, and place your order. We offer fast and reliable delivery across Australia. For delivery details, please refer to our Delivery Page.
