Supercapacitors help building long time constant resistor-capacitor circuits. This property helps them withstand high voltage transient surges and dissipate transient energy in the resistive element of the circuit without exceeding the supercapacitor’s DC voltage rating, which is usually between 2.5 to 4 V. SCASA is a patented technique, which was commercialized within the last five years. Successful implementation of this circuit topology, despite its simplicity, is quite dependent on the selection of the core of the coupled inductor utilized. This paper provides the essential details of the process of selecting the core for the magnetic component required, with a brief comparison of SCASA technique with a traditional surge protector, without any supercapacitors.