RL Time Constant Calculator Formula
Understand the math behind the rl time constant calculator. Each variable explained with a worked example.
Formulas Used
Time Constant (τ)
tau = inductance * 1e-3 / resistanceTime Constant (ms)
tau_ms = inductance / resistanceVariables
| Variable | Description | Default |
|---|---|---|
inductance | Inductance(mH) | 50 |
resistance | Resistance(Ω) | 10 |
How It Works
RL Time Constant
The RL time constant governs how quickly current builds up or decays in an inductor-resistor circuit.
Formula
τ = L / R
After one time constant, the current reaches 63.2% of its final steady-state value.
Worked Example
A 50 mH inductor with a 10 Ω resistor.
inductance = 50resistance = 10
- 01τ = L / R
- 02τ = 50e-3 / 10
- 03τ = 0.005 s = 5 ms
Ready to run the numbers?
Open RL Time Constant Calculator