Capacitors

A capacitor is an electronic device that stores and releases electrical energy. It has two terminals or conductors separated by an insulating material or vacuum. AC capacitors are among the most important components found in most electronic circuits. The most frequent uses of capacitors are energy storage, electronic noise filtering, remote sensing, and power conditioning. Capacitors improve energy usage and boost system performance by reducing voltage drop, limiting energy​ losses, filtering signals, suppressing voltage spikes, and boosting energy efficiency.

Essential Applications of Capacitors

Capacitors can serve as a type of temporary battery because they store energy. In uninterruptible power supply circuits, capacitors can keep power flowing when there's a brief power outage. Car audio capacitors are also used in vehicles to store and release energy after activating the amplifier. Power conditioning is another vital application of capacitors. They give consistent energy by smoothening current fluctuation and holding the energy for the DC power supply circuit. Capacitors also work in power factor correction devices to boost energy efficiency.

Types of Capacitors & Their Uses

Capacitors are usually divided into two categories: fixed and variable capacitors. The fixed capacitor category has many commonly used variants including ceramic capacitors. A popular model of ceramic capacitor is the multi-layer ceramic capacitor. Others are film capacitors, electrolytic capacitors, parallel-plate capacitors, and super capacitors. Some capacitors are also named based on their uses including motor capacitors such as air conditioner capacitors, motor capacitors, and HVAC capacitors.

How to Select the Right Capacitor

Some of the factors to consider when choosing capacitor types include: size, leakage current, maximum voltage, and series resistance. If high capacitance is needed, a large capacitor will be required. The space where the circuit will rest will also affect the size of the capacitor. In some cases, having a series of small capacitors may be more suitable than using one big capacitor. Also, calculate the series resistance to reduce power loss and heat if you arrange many capacitors in series on the PCB. Ensure the voltage in the circuit will be less than the maximum voltage rating.