Introduction
Capacitors store electrical energy in an electric field. They are used for filtering, energy storage, and timing.
The RC Time Constant (τ)
When a capacitor (C) is charged through a resistor (R), the time it takes to reach 63.2% of the supply voltage is called one time constant.
τ = R × C
- R in Ohms (Ω)
- C in Farads (F)
- τ in Seconds (s)
Common Applications
- Filtering: Removing noise from power supplies.
- Timing: Creating delays in circuits (like the 555 timer).
- Coupling: Passing AC signals while blocking DC.