Aluminium Capacitors

Aluminium capacitors are a type of electrolytic capacitor, also known as an electrolyte condensator. A capacitor is a two-terminal electrical component that can store energy, somewhat like a battery. Electrolytic capacitors are characterised by their high capacitance values and are commonly used in applications requiring large energy storage in a compact form. They are polarised, which means they have a distinct positive and negative terminal, and they typically offer higher capacitance per unit volume compared to other types of capacitors.

Aluminium capacitors are made with high purity grade Aluminium, which is used to create the anode foil and the cathode foil upon which electrolysis is applied to form an extremely thin insulating layer of aluminium oxide, which acts as the dielectric of the capacitor. Aluminium capacitors are found in many applications such as power supplies, computer motherboards and domestic appliances.

Types of Aluminium Capacitors

Depending on the nature of the electrolyte, capacitors may also be referred to as "wet" meaning they have a liquid electrolyte, or solid. Solid Electrolytes may be hybridised with Aluminium but normally refers to Polymer or Tantalum based capacitors

Aluminium Electrolytic Capacitors

Electrolytic capacitors consist of an electrolyte which is a liquid or gel that consists of a large concentration of ions, and when voltage is applied across its terminals, it leads to charges being stored on the anode and cathode foils. The electric charge that can be stored by the capacitor is measured in Farads but usually in the range from nanofarads to millifarads. Aluminium capacitors are used where high capacitance values to provide smoothing and filtering functions in the circuit. Commonly used in DC Power supplies due to their large capacitance and their compact size which helps to reduce the ripple voltage. Aluminium Electrolytic capacitors have reasonable Equivalent Series Resistance (ESR) but have the lowest leakage current from all capacitor types.

Polymer Electrolytic Capacitors

Polymer capacitors (also known as polymer electrolytic capacitors or polymer e caps) have conductive polymer as their electrolyte material within a layered aluminium design. These capacitors combine unique properties from the polymer material in terms of high conductivity, extended temperature range and no risk of drying out – to make a capacitor that offers large capacitance and very low ESR (equivalent series resistance) with high ripple current capability and offers a longer operating life. Polymer capacitors offer a lot of package options between 2.2 to 470 microfarad.

Hybrid Capacitors

Hybrid capacitors (polymer hybrid aluminium capacitors) are a mix of wet electrolyte and solid polymer. In this sense, they combine the best of both electrolytes. These capacitors offer high endurance, low ESR, and a high tolerance for ripple current. Hybrid capacitors also feature stable electric characteristics at high frequencies whilst maintaining reliability. The liquid electrolyte keeps the Leakage current very low and also allows self-repairing of the aluminium foils which prevent a drop in capacitance.

Rolled Capacitor and Aluminium Capacitor

Rolled capacitors are constructed by rolling the anode and cathode foils, separated by a dielectric material, into a compact cylindrical shape. This technique is commonly used in aluminium electrolytic capacitors to achieve high capacitance and a compact design. The rolled construction enhances their efficiency in applications requiring large energy storage and space-saving solutions.

Industrial Applications of Aluminium Capacitors

Aluminium capacitors are widely used in various industrial applications due to their high capacitance and reliability. These capacitors are essential in the following use cases:

• Power Supplies: Used for smoothing and filtering voltage fluctuations, ensuring stable power output. They help in reducing ripple voltage, thereby protecting sensitive electronic components.
• Computer Motherboards: Integral for managing power distribution and filtering noise in complex circuits. They enhance the overall stability and performance of the motherboard by providing reliable power delivery.
• Automotive Electronics: Employed in control units and infotainment systems to provide stable power and improve performance. Aluminium capacitors contribute to the efficiency and longevity of automotive electronic systems.
• Domestic Appliances: Found in devices like washing machines and refrigerators for power management and efficiency. They ensure the smooth operation of these appliances by mitigating voltage spikes and fluctuations.
• Renewable Energy Systems: Crucial for energy storage and conversion in solar and wind power applications. They aid in storing energy efficiently and converting it to a usable form, thereby supporting sustainable energy solutions.

How to Choose the Right Aluminium Capacitor for Your Needs

In order to choose the right aluminium capacitor for your needs, consider factors such as capacitance value, voltage rating, equivalent series resistance (ESR), and physical size.

For applications requiring high capacitance in a compact form, aluminium electrolytic capacitors are ideal. Always check to ensure the capacitor can handle the voltage and current demands of your circuit.

RS Australia offers a wide range of high-quality aluminium electrolytic capacitors to suit various industrial and commercial needs.

Buying Aluminium Capacitors: Ordering & Delivery

RS Australia is a trusted supplier and distributor of aluminium capacitors and electrolyte condensators from leading brands such as Chemi-Con, Cornell-Dubilier and Kemet. To place an order online, simply browse our extensive catalogue, filter your preferred products based on our extensive specifications, and add to your cart.

RS Group offers fast delivery of aluminium capacitors and all sorts of other electronic components. For more details on delivery services and fees, please refer to our Delivery Page.