Benefits of using Film/Foil Capacitors

Film/foil capacitors consist of two aluminium foils acting as the electrodes. The foil electrodes are separated by a polymer film dielectric. These materials are non-inductively wound to form the capacitor element. The wire leads are soldered directly to the aluminium foil electrode which extends out on both sides of the capacitor element.

A sufficient thickness of dielectric film is essential to withstand the applied electric field, this is because the foil electrodes are typically about 5 micrometres thick and the dielectric is usually thicker than metallised film capacitors.

The electrodes in metallised film capacitors usually have an extremely thin layer of metal which is vacuum-deposited directly onto the dielectric film. The wire lead is connected to the electrodes by a metal spray which is applied to each end of the capacitor element, the lead wire is soldered to this metal end spray.

Metallised film capacitors are manufactured using a much thinner dielectric film than those typically used in the same rated film/foil design. This is because the self-healing characteristics of the metallised film, it removes a fault or short circuit in the dielectric film by vaporizing the metal electrode surrounding the defect and isolating area.

Benefits
Film/foil capacitor designs usually offer higher insulation resistance, better capacitance stability, high current carrying capabilities for pulse applications and a lower dissipation factor. The metal foil electrodes act as a heat conductor, transferring the the heat out from the interior of the unit enabling excellent heat dissipation. The superb heat dissipation allows for a higher voltage application, in comparison to the metallised capacitor at the same frequency. The extended foil design also allows for operation at higher peak currents and faster duty cycles.

Capacitors using polymer film technology provide a wide range benefits, including:

- High reliability
- High pulse currents
- Non-standard values and/or tight tolerance
- Low dielectric absorption
- Extremely small capacitance changes with applied voltage
- Capacitance stability over frequency
- Small variation in capacitance with temperature change

GD Rectifiers offers a wide range of API Capacitors, including: AC, DC, Energy Storage, Snubber, Track Circuit, Low Temperature and Custom Designed Capacitors - http://www.gdrectifiers.co.uk/products/category/passives/capacitors/

For further information on their wide range of capacitors, please call: 01444 243 452 or email: enquiries@gdrectifiers.co.uk.

GD Rectifiers is a Global Manufacturer and Distributor of products, services and solutions to commercial and industrial users of power electronic components.

Established in 1964, GD Rectifiers has over 50 years of extensive experience across a large range of markets, specialising in new and current technologies for industrial power control applications. An extensive product offering has built GD Rectifiers exceptional reputation as the go-to power specialist with innovative experience across: Aviation, Automotive, Rail, Medical, Industrial and Electronics markets.

GD Rectifiers have extensive experience in the rail industry and are RISQS Qualified.

GD Rectifiers is a ISO 9001:2015 registered company that design and develop bespoke power semiconductor assemblies to control voltage, current and frequency for international industrial markets.

GD Rectifiers designs and manufactures Selenium and Silicon Rectifiers, Suppressors, Converters, Inverters, Regulators and all other power products for Industrial power control applications. The company distributes state of the art Diodes, Thyristors, IGBTs and MOSFETs from the world’s leading manufacturers including: IXYS, IXYS UK Westcode, Semikron and EDI.

GD Rectifiers manufacture an extensive range of power components and assemblies. The company also supplies a wide range of Heat Sinks suitable for Power Semiconductors, LED Lighting and similar applications. GD Rectifiers also offer a repair and replacement service for faulty or ageing Semiconductor Rectifiers, Converters, Inverters and Regulators.

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