Capacitor 101

Capacitors stand as the cornerstone in nearly every electronics and electrical circuit, playing a pivotal role in their functionality. They contribute significantly to the seamless operation of circuits, ensuring that devices remain free from unwanted noise and maintain a reliable and steady output.

A capacitor bears a resemblance to a battery, despite their distinct operational mechanisms. Both devices serve the common purpose of storing electrical energy. A capacitor operates on a simpler principle – it lacks the ability to generate new electrons; instead, it functions solely to store them. The term "capacitor" is derived from its "capacity" to store energy.

The difference between a capacitor and a battery is that a capacitor can dump its entire charge in a tiny fraction of a second, where a battery would take minutes to completely discharge. That's why the electronic flash on a camera uses a capacitor — the battery charges up the flash's capacitor over several seconds, and then the capacitor dumps the full charge into the flash tube almost instantly. 

Capacitors exhibit remarkable versatility, tailored to serve diverse applications ranging from minute plastic capacitors in calculators to powerful ultra capacitors capable of energizing commuter buses. The functionality of capacitors is closely tied to their types, each uniquely suited for specific purposes. Air capacitors find relevance in radio tuning circuits, Mylar capacitors are commonly employed in timer circuits for devices like clocks, alarms, and counters. Glass capacitors excel in high-voltage applications, while ceramic capacitors prove effective in high-frequency applications such as antennas, X-ray, and MRI machines. Super capacitors, on the other hand, play a pivotal role in powering electric and hybrid cars.