RL Circuits — iLearnSTEM Labs

iLearnSTEM Labs

labs.ilearnstem.ca — Virtual Science Laboratories

Ontario Curriculum · Grades 9–12Beta

RL Circuitsloop open

pair 10 Ω · 22 Hτ 2.20 sV_L 0.000 VI —U 0.00 Jt½ 1.52 s

An open loop is death to inductor current — the field collapsed the instant the switch broke the path. Capacitors park charge; coils cannot park current.

Electronics Lab 04 · RL Circuits — τ = L/R, I = I∞ + (I₀ − I∞)·e^(−t/τ) in exact closed form · real time, no warp · drag to orbit, scroll to zoom

Bench supply

Supply voltage9.0 V

Sets the current ceiling: the loop climbs toward I∞ = V/R — the resistor alone decides how high, the coil only decides how slowly.

The RL pair

Resistor

the bands on the bench resistor

Inductor

Swapping in a fresh coil starts it at zero current. τ = L/R runs the bench: right now 2.20 s.

Switch

What the bench is doing

Loop open — the coil is quiet and the meter reads zero. Flip to energize to build the field.

V_L 0.003 Vno current