Capacitors are the second most common passive component in electronics after resistors. They’re used to store and release energy, filter signals, and smooth out power supply fluctuations.

How Capacitors Work:

Capacitors consist of two conductive plates separated by an insulating material called a dielectric. When voltage is applied, electrons accumulate on one plate, creating an electric field. Once the voltage source is removed, the stored energy is gradually released.

Capacitance (C) is measured in Farads (F) and determines how much energy a capacitor can store.

Common Types of Capacitors:

• Ceramic Capacitors: Cheap, non-polar, low capacitance.
• Electrolytic Capacitors: High capacitance, polarized, used in power supply filtering.
• Tantalum Capacitors: Smaller than electrolytic, stable but expensive.
• Film Capacitors: Great stability, used in audio circuits.
• Supercapacitors: Extremely high capacitance, used for energy storage.

Key Parameters:

• Capacitance (µF, nF, pF)
• Voltage Rating
• Tolerance
• ESR (Equivalent Series Resistance)

Applications:

• Power supply smoothing
• Signal filtering in audio systems
• Timing applications (RC circuits)
• Snubber circuits for motors

Capacitors are the backbone of analog electronics, and choosing the right one is crucial for performance and reliability.