Electrical & Computer
Diode I–V Lab
A diode is the textbook nonlinear component, and this lab makes its behaviour concrete. The current follows the Shockley equation I = Is·(e^(V/nVt) − 1): essentially zero (−Is) in reverse, then climbing exponentially in forward bias — which is why a silicon diode seems to 'switch on' so abruptly around 0.6–0.7 V. Tune the saturation current Is, the ideality factor n and the temperature (which sets the thermal voltage Vt = kT/q ≈ 25.85 mV at 300 K) and watch the knee shift. Switch on the resistor load line and the operating point is solved for you — the single (Vd, I) that satisfies both the diode curve AND Kirchhoff's voltage law Vs = I·R + Vd — the graphical method every circuits course teaches for analysing a nonlinear element in a linear circuit.
25.85 mV
Thermal voltage Vt
1.00 pA
Saturation Is
574.19 mV
Op. point Vd
4.43 mA
Op. point I
The Shockley diode obeys I = Is·(e^(V/nVt) − 1). Forward current rises exponentially, so a silicon diode appears to switch on near 0.6–0.7 V. Overlay a resistor load line (I = (Vs − V)/R) and the operating point sits where it crosses the curve — graphical circuit analysis in one picture.
How to use this simulation
A diode is the textbook nonlinear component, and this lab makes its behaviour concrete. The current follows the Shockley equation I = Is·(e^(V/nVt) − 1): essentially zero (−Is) in reverse, then climbing exponentially in forward bias — which is why a silicon diode seems to 'switch on' so abruptly around 0.6–0.7 V. Tune the saturation current Is, the ideality factor n and the temperature (which sets the thermal voltage Vt = kT/q ≈ 25.85 mV at 300 K) and watch the knee shift. Switch on the resistor load line and the operating point is solved for you — the single (Vd, I) that satisfies both the diode curve AND Kirchhoff's voltage law Vs = I·R + Vd — the graphical method every circuits course teaches for analysing a nonlinear element in a linear circuit.
Everything runs in your browser — no sign-up, no download. Change a value and the result updates instantly, so you can build a feel for how each input shapes the outcome. It pairs with Crameleon's practice exams and step sheets when you want to go from intuition to working the problems.