When approaching storm activity, the integrated sensor measuring the surrounding electrical field, releases the impulse device such as most of usual Early Streamer Emission systems. It almost immediately reverses the polarity of their head, creating a sudden amplification of the electrical field on its tip.
The innovation comes from the use of a second device, named « power device », which collects and stores energy in power capacitors. The Active 2D® is in this way permanently pre-loaded of an important energy which allows maintaining the ascendant tracer propagation.
When the downward leader enters in the protection area of the lightning conductor, the measured current strongly increases. As soon as this current is superior to a characteristic threshold, the power capacitors discharge and release the necessary energy for the propagation of the leader.
In this last device, the lightning conductor’s head is used as a capture device. It is, by consequence, electrically insulated from the earth.