The applet shows a simple LC resonant circuit topology (constructed for purely demonstrational purposes), its operation in the time domain, and the state-plane trajectory, also known as an uZi-diagram. The uZi-diagram is a convenient tool to analyse resonant effects as they often occur in power electronics topologies. The x-axis describes the capacitor voltage of the topology, and the y-axis describes the inductor current multiplied with Z = sqrt(L/C).

• Change the initial conditions defined by the capacitor voltage uC(0) and inductor current iL(0) via red triangle symbols that can be clicked. The initial conditions define the starting point on the spiral shown in the state-plane trajectory (initial point shown as dot in magenta).
• Change the DC voltage (drag red arrow) to change the size of the spiral.
• Change the DC current (drag red arrow) to change the position of the spiral in the plane.
• Change the resistor value to change the damping effect.
• Drag the red time slider. The actual state on the trajectory is then given by the black dot in the uZi-diagram.