RC Time Constant Calculator
Calculate the RC time constant of a resistor-capacitor circuit: tau = R * C.
Time Constant (τ)
1.0000 s
Time Constant (τ) vs Resistance
Formule
## RC Time Constant The time constant characterizes how quickly a capacitor charges or discharges through a resistor. ### Formula **τ = R * C** After one time constant, the capacitor reaches about 63.2% of its final value. After 5τ, it is over 99% charged.
Exemple Résolu
A 10 kΩ resistor with a 100 μF capacitor.
- 01τ = R * C
- 02τ = 10000 * 100e-6
- 03τ = 1.0 s
- 045τ = 5.0 s (99.3% charged)
Questions Fréquentes
What does one time constant mean physically?
After one time constant, the voltage across the capacitor has reached 63.2% of the supply voltage during charging, or dropped to 36.8% during discharging.
Why is 5 time constants considered fully charged?
After 5τ, the capacitor has reached 99.3% of its final value. The remaining 0.7% is negligible for most applications.
Where are RC circuits used?
RC circuits are used in filters, timing circuits, smoothing power supplies, debouncing switches, and many signal processing applications.
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