Lightning current and surge current waveform are basically the same, just different range, generally in the standard of IEC61000-4-5 specified voltage and current range is known as the surge; This range is called lightning if the voltage and current are higher than the standard. Also, for the protection circuit speaking, high grade lightning protection circuit is often known as lightning protection device or lightning protection circuit; Standard IEC61000-4-5 protection circuit within the specified voltage and current ranges, commonly referred to as surge protection circuitry.
For the test, a lot of people are in doubt about the difference of testing voltage and current wave . What’s the difference between the current and voltage testing? In fact the two are unified, signal output of surge signal generator can’t leave the concept of voltage, and directly output a current waveform. Surge signal generator output voltage or current wave is depend on the input impedance of load test equipment port. When the load test equipment port presents high impedance, surge signal generator in the form of voltage wave apply interference signal to the test port; When the load tested equipment port presents low impedance, surge signal generator output current wave, and through it to protection circuit.
Lightning current signal generator is very similar with the principle of surge generator, surge and lightning current signals are in the form of voltage pass to the test port, just the impedance of the port presented different, so the load current is different.