Mainstream on the time constant of a capacitive circuit

The time constant (τ) of a capacitive circuit is a measure of how quickly a capacitor charges or discharges through a resistor. It is defined as:

τ = R × C

where:

• R is the resistance in ohms (Ω)
• C is the capacitance in farads (F)

The time constant indicates the time it takes for the voltage across the capacitor to reach approximately 63.2% of its maximum value during charging or to fall to about 36.8% during discharging.

For example, if R = 2 Ω and C = 3 F, then:

τ = 2 Ω × 3 F = 6 seconds

This means it takes 6 seconds for the capacitor to charge to about 63.2% of the maximum voltage.