Circuit Simulator - Tunnel Diode Relaxation Oscillator

This example shows a tunnel diode used to make an oscillator. The two resistors bias the diode in its negative resistance region. As the current begins to flow through the inductor, the voltage across the tunnel diode increases until it hits the negative resistance region of its curve. The inductor still has a positive voltage across it, which requires an increse in current, so will not allow the tunnel diode to enter the negative resistance region. Instead, it jumps over to the right side of the curve. Now the inductor has a negative voltage, so the current slows down and the tunnel diode traces out the right side of its curve until it hits the negative resistance region again, at which point the tunnel diode jumps over to the left side of the curve and the cycle begins again.

Credits: Mr. Paul Falstad.