🔬 Electro-Tutor Virtual Lab: Professional Edition

How this works: Below the knee voltage the depletion barrier blocks current (watch holes and electrons get pushed away from the junction in reverse bias). Past the knee (0.7V Silicon / 0.3V Germanium) the barrier collapses and holes/electrons cross and recombine at the junction - current shoots up. Push forward voltage too far past the knee, or reverse voltage past the breakdown point (V_BR), with no current-limiting resistor in the circuit, and the diode will be permanently damaged - exactly like a real diode driven outside its safe ratings.

How this works: Base current controls a much larger Collector current - a tiny wiggle at the valve, a big rush at the tank. Because more Base voltage means MORE current pulled through R_L, the Collector voltage actually drops when the input rises - that's the 180° phase inversion. C₂ gives AC signals a shortcut around R_E straight to ground, unlocking much higher gain; remove it and R_E fights the signal, crushing the gain down to near unity. Turn C₁ off and the AC signal can't even reach the Base at all - the output goes flat, showing why a coupling capacitor is essential. Push the input amplitude too high and the output slams into V_CC (cutoff) at the top and 0V (saturation) at the bottom - gain has limits.