Varistors: Effective Overvoltage Protection for Your Electronics
Sensitive electronic circuits and devices require reliable protection against transient overvoltages and voltage spikes. Varistors (Voltage Dependent Resistors) are essential components for this purpose.
As an experienced distributor, alfatec GmbH & Co. KG offers a wide range of high-quality varistors from our partners Samwha and Chemi-Con to ensure the longevity and reliability of your applications.
Varistors as Overvoltage Protection: Function and Types
A varistor is a passive electronic component whose resistance is highly voltage-dependent. Under normal operating conditions, it has a very high resistance and has little effect on the circuit.
However, when an overvoltage exceeds a certain threshold, the varistor’s resistance drops dramatically within nanoseconds. It safely diverts the harmful surge current and clamps the voltage to a level safe for downstream electronics.
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Contact us nowOverview of Varistor Types
- Metal Oxide Varistors (MOVs): The most common type, made primarily of zinc oxide (ZnO) with small amounts of other metal oxides. MOVs offer excellent cost-performance, high energy absorption, and fast response times. alfatec offers a wide range of MOVs.
- Multilayer Varistors (MLVs): Compact ceramic components ideal for PCB-level protection and low-voltage applications. They offer very fast response and good pulse handling.
- Standard Varistors: For general-purpose overvoltage protection.
- High-Current Varistors: Designed to handle very high surge currents, such as in lightning protection and industrial systems.
- Silicon Varistors: Provide precise clamping voltages but are typically more expensive and have lower energy absorption than MOVs.
- Square Varistors: Special form factors for specific installation or performance requirements.
alfatec focuses on supplying high-quality MOVs (standard and high-current) and MLVs from leading manufacturers.
Technical Parameters of alfatec Varistors
- Clamping voltage: Protection solutions up to 1800 V
- Surge current capability: Ranges from low to very high pulse energy handling
- Response time: Typically in the nanosecond range
- Operating temperature: Standard −40°C to +85°C, extended up to +125°C depending on model
- Material: Primarily zinc oxide ceramic for MOVs
Our partner for varistors
Varistors from Samwha and Chemi-Con at alfatec
alfatec relies on the proven quality and innovative strength of Samwha and Chemi-Con in the field of varistors and surge protection.
Samwha Varistors
- Broad portfolio: Wide selection of MOVs for various voltage and energy requirements
- Reliability: Known for robust and durable components, ideal for industrial and power supply applications
- Applications: Telecommunications, household appliances, industrial controls, power supplies
Chemi-Con Varistoren:
- Hohe Performance: Chemi-Con Varistoren sind für ihre exzellenten elektrischen Eigenschaften und hohe Zuverlässigkeit, auch unter anspruchsvollen Bedingungen, bekannt.
- Spezialisierte Serien: Bietet oft Serien, die spezifische Normen (z.B. für Automotive) erfüllen oder für besonders hohe Stoßströme ausgelegt sind.
- Anwendungsbereiche: Automotive-Elektronik, hochwertige Netzteile, Messtechnik, Telekommunikationsinfrastruktur.
Chemi-Con
As the world's largest manufacturer of aluminium electrolytic capacitors, Chemi-Con has been driving development in this field since 1931. The core product portfolio is supplemented by other innovative components such as tantalum electrolytic capacitors, film capacitors, supercapacitors and many more, so that the manufacturer is characterised by a wide range of standard and special types of high quality, reliability and performance.
Samwha
The Samwha Capacitor Group is a leading global manufacturer of passive electronic components such as aluminum electrolytic and ceramic capacitors. Since 1956, Samwha has stood for quality, innovation, and energy efficiency. As a partner of alfatec, Samwha offers a wide range of products with high availability, reliable performance, and an excellent price-performance ratio—ideal for applications in industry, automotive, telecommunications, and more.
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alfatec – your partner for high-quality electronic components
As your expert partner for electronic components, alfatec supports you in selecting the right varistors for your applications. We offer comprehensive advice and are happy to answer any questions you may have about power modules.
Do you have questions about our varistors or would you like a personal consultation? Feel free to contact us.