Is the maker of Pmags. These self powering electronic ignitions are single module units that mount entirely in the magneto location on the engine, and have an internal alternator that self powers the system above some nominal RPM. They do require power from a battery (usually ship's power) to provide spark for engine starting and low RPM, about 900 or less?
They are very popular with the RV crowd, and I have one on my RV-8 and my Thorp T-18.
They have variable timing, and are nominally set to 0 degree BTC for starting. Then they have an RPM based advance, and a manifold pressure timing control as well.
Cockpit control and monitoring units are available.
These are for use on experimental aircraft only.
I notice less RPM drop with the Pmag running during a mag check, than when the magneto is on. Also, the engine idles smoother and lower RPM idle is possible without fear of the engine stopping with a light wood prop.
These units had an early history of some failures, but improvements have been steady and successful. I've certainly had more mag trouble than Pmag trouble, but that could be because my mags were old...
On the other hand, my son is cautious, and prefers magnetos.
The plain magneto ignition suffers from a number of problems, however it is tried-and-true. Let's discuss this new technology and how it applies to us.