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Polyester Film Capacitors: Reliable & Efficient from alfatec

Polyester capacitors are a well-established and highly versatile component in the world of electronics. As one of the most widely used types of film capacitors, they offer an excellent balance of performance, reliability, and cost-effectiveness. 

alfatec GmbH & Co. KG supplies high-quality polyester film capacitors, especially from our long-standing partner Faratronic, for a wide range of applications. Discover the advantages and technical capabilities of these robust components. 

Bild eines Polyester-Kondensators, ein passives Bauelement für zuverlässige Kapazität und stabile Leistung in elektronischen Schaltungen.

What Makes Polyester Capacitors Stand Out?

Polyester capacitors, also known as MKT or MET capacitors (when metallized film is used), belong to the family of plastic film capacitors. 

Their core element is a thin polyester film (polyethylene terephthalate, PET) used as the dielectric. 

This film is typically vacuum-metallized with a thin metal layer that serves as the electrode. The metallized construction not only enables high capacitance density and miniaturization but also provides self-healing properties in the event of minor internal breakdowns. 

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Advantages and Features of Polyester Capacitors
High temperature resistance: Usable up to 125°C, often exceeding standard polypropylene capacitors.
Good dielectric strength: Enables high rated voltages in compact sizes.
High insulation resistance: Important for long-term stability and low self-discharge.
Cost-efficiency: Excellent price-performance ratio for many standard applications.
Reliability: Especially in metallized versions with self-healing properties.
Versatility: Available in numerous form factors (box, dipped, axial, stacked/SMD) and lead spacing options.
Faratronic quality: Benefit from the consistent manufacturing quality and reliability of a leading global supplier.
Application Areas
General DC applications: Coupling, decoupling, bypassing, blocking.
Filtering: Low-frequency filtering in power supplies and audio circuits.
Consumer electronics: TVs, audio equipment, household appliances.
Industrial electronics: Controllers, power supplies, lighting (e.g., ballasts).
Telecommunications: Base stations and end-user devices.
Timing circuits: Used in oscillators and timers where moderate stability is sufficient.

Construction Types Offered by alfatec

In cooperation with Faratronic, alfatec offers a wide range of polyester capacitors in various form factors to meet your specific design and assembly requirements: 

  • Box Type: Rectangular plastic-encased capacitors, often flame-retardant per UL94 V-0. Ideal for through-hole technology (THT) on PCBs. Available in various lead spacing options.
  • Dipped Type: Epoxy-coated capacitors offering good environmental protection. Also for THT mounting, often more compact than box types with the same pitch.
  • Axial Type: Cylindrical form with leads on both ends. Suitable for THT or free wiring.
  • Stacked Version : In this design, the metallized polyester film and the electrodes are not wound, but rather arranged in a flat, stacked configuration. This arrangement results in significantly better performance with regard to electrical properties. In particular, the lower equivalent series resistance (ESR) and the lower equivalent series inductance (ESL) are noteworthy.

Technical Parameters and Performance Characteristics 

Faratronic polyester film capacitors offered by alfatec feature solid technical specifications for a wide range of applications: 

  • Rated voltage: Wide range available, with types up to 1250 VDC.
  • Capacitance range: High capacitance values achievable for film capacitors, up to 47 µF.
  • Operating temperature: Suitable for demanding environments, with max temperatures up to +125°C.
  • High insulation resistance: Minimizes leakage current and ensures stable performance, especially in DC applications.
  • Good capacitance stability: Reliable performance over time and temperature.
  • Defined tolerances: Available in standard tolerances (e.g., ±5%, ±10%, ±20%) for precise circuit design. 

Our partner for polyester capacitors

Logo Faratronic

Faratronic

Faratronic is one of the world's largest manufacturers of film capacitors, producing DC links, X & Y capacitors and snubber film capacitors, among others. As one of the top electronic component companies in China, Faratronic invests around 3% of its turnover in R&D and supplies the automotive, energy and industrial sectors with perfectly customised solutions.

 

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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 polyester capacitors 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 polyester capacitors or would you like a personal consultation? Feel free to contact us.