A supernode exists when an ideal voltage source appears between any two nodes of an electric circuit. The usual way to solve this is to write KCL equations for both nodes and simply add them together into one equation ignoring the voltage source in question. However, this would mean one less equation than the number of variables (node voltages) present in the circuit. A constraint equation can be easily speciﬁed given by the magnitude of the ideal voltage source present between the nodes and the respective node voltages. The following example will help clarify this scenario.