Electronics
RC, RL and RLC Circuits
A resistor, a coil and a capacitor in one loop. The two stores pass energy back and forth, so the circuit rings, and one number, the damping ratio ζ, decides whether it rings, settles as fast as it can or crawls. The same two poles decide which frequencies get through.
The poles panel is the same circuit seen from the Laplace side: move R and watch the two poles travel
Current—
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Circuit
Side panel
Source
slowfar past resonance
rings for agesrefuses to ring
Values
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What to observe
- With R low the two stores argue: the capacitor dumps into the inductor, which overshoots and charges it the other way, so the circuitrings. The energy bars trade back and forth while R bleeds the total away.
- Raise R to ζ = 1 and the ringing stops: critically damped, the fastest approach that never overshoots. On the Poles panel the complex pair has just met on the real axis; push R further and they split along it and the response turns sluggish.
- Drive an underdamped circuit with a sine right at f₀. The reactances cancel, only R is left, and the capacitor voltage builds to about Q times the source.
- RC and RL have one store, so one time constant and an exponential that never overshoots. The capacitorand inductor pages take those apart.
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