Why Rotax-Ducati have implemented such a complex kill ignition circuit in CDI modules?

[junav]

This is my first intervention in this magnificent forum and I would like to introduce myself.

My name is Juan Navarro and I recently obtained my pilot's license for ultralight aircraft in Spain. I recently bought a Skyranger with Rotax 912 ULS engine from 2005.

I recently had the opportunity to open and dig up the circuit board of a CDI module from another pilot's plane that had to be replaced.

With the module open, the electronic circuit revealed and the information from this and other forums, I have been able to understand how the Ducati-Rotax CDI module works.

However, there is a dark point that I cannot fully understand. For me, it is surprising to see that Ducati-Rotax does not use a simple short-circuit to ground of the charge coil to kill the ignition. On the contrary, they implements a very complex circuit with several semiconductors (a MOSFET, a thyristor and a bipolar transistor) as active elements.

Reading threads of this forum, I have noticed that here are several users who have a lot of knowledge of these CDI modules (M. Kyle, Downunder and others).  For this reason, I raise the question expressed in title thread in this discussion forum.

A cordial greeting from the “antipodes”.

[Blueadventures]

Welcome and enjoy.  I have a Nynja with 912ULS so a Skyranger fan.

[skippydiesel]

Straight from The Rotax Forum (with love?)