Ignition coil patents of interest: trimmers, chainsaws , lawnmowers

First an explanation to Bert . I had promised a PM , but the patents may be of interest to other forum visitors. There are many problems in the forum concerning "no spark" and what to do. The patent articles are very technical, but the summaries are in English and worth reading. These coils have been constantly improved. Among the benefits to readers will be how complex these modules are and so can not be easily tested. Next , to me , great insight into timing which some readers have questioned, Type in a search word "US" followed by the 7 digits. Do not "turn off" due to the schematics, etc.

US 5295465 (Kohler 1994))
US 3484677A (Magnetron) 1969
US 6388445 (Walbro timing)
US 4817577 (Briggs 1988))
US 8807119 (Ti Gp 2014 timng and anti- kickback)
US 5058543A (Stens 1991)
US 3894525 (Bosch "thick film" chip)

EP 1691053B1 (Walbro)