What is the Difference Between AC Capacitor and DC Capacitor?

The main difference between AC and DC capacitors lies in their polarity and the type of circuits they can be connected to. Here are the key differences:

1. Polarity: DC capacitors have polarity, meaning they have positive and negative poles. AC capacitors, on the other hand, do not have polarity.
2. Circuit Compatibility: AC capacitors, also known as non-polarized capacitors, can be connected to both AC and DC circuits. DC capacitors, which are polarized, can only be connected to DC circuits.
3. Capacity and Withstand Voltage: DC capacitors have a high capacity but a relatively small withstand voltage, which decreases over time. AC capacitors generally have a lower DC rating.
4. Dielectric Degradation: AC capacitors are designed to handle the formation of corona in microscopic air bubbles between the foil layers under changing voltages. This is not an issue with DC capacitors.

In summary, AC capacitors can be used in both AC and DC circuits, have no polarity, and are designed to handle changing voltages. DC capacitors have polarity, can only be used in DC circuits, and have a high capacity with a lower withstand voltage. When selecting a capacitor, it is essential to consider the circuit type and voltage level to ensure proper operation and safety.

Comparative Table: AC Capacitor vs DC Capacitor

The main difference between AC and DC capacitors lies in their polarity and the type of current they are designed to handle. Here is a table comparing the two:

AC capacitors, also known as non-polarized capacitors, can be used in both AC and DC circuits if the withstand voltage is sufficient. They are designed for AC circuits and can act as filters, allowing AC signals to pass through while blocking DC components.

DC capacitors, or polarized capacitors, can only be used in DC circuits. They have a positive and negative pole and are generally used in DC power supplies and electronic devices. The capacity of DC capacitors is very high, but their withstand voltage is relatively small, and both capacity and withstand voltage will be consumed with time.