Bulkkapacitorer

Bulkkapacitorer, often referred to as bulk capacitors, are a type of capacitor used to smooth out voltage fluctuations in electronic circuits, particularly in power supply applications. Their primary function is to act as a reservoir of electrical energy, absorbing transient voltage spikes and supplying current during brief dips. This helps to maintain a stable and consistent voltage for sensitive components downstream.

The term "bulk" in bulkkapacitorer refers to their typically large physical size and high capacitance values compared to other capacitor types like ceramic or film capacitors. These large capacitance values are crucial for their role in filtering low-frequency ripple, which is common in AC-to-DC conversion processes. They are often the first line of defense in a power supply's filtering stage.

Commonly, bulkkapacitorer are electrolytic capacitors, with aluminum electrolytic capacitors being the most prevalent. These utilize an electrolyte, which is a chemical compound that conducts electricity, to achieve their high capacitance density. However, this electrolyte can degrade over time, especially at elevated temperatures, leading to a decrease in capacitance and an increase in equivalent series resistance (ESR). This degradation is a common failure mode for electrolytic capacitors.

Other types of bulkkapacitorer include tantalum and polymer electrolytic capacitors, which offer advantages in terms of stability, ESR, and lifespan, but are often more expensive. The selection of a specific type of bulkkapacitor depends on the requirements of the application, such as operating voltage, desired lifespan, temperature range, and cost constraints. Their presence is vital for the reliable operation of most electronic devices that draw power from an alternating current source.