CD Ignition

[Terry Sare]

     There have been several articles on building your own in Radio 
     Electronics, Electronics Today (I think that is the name -- its 
     English). That is all I can remember off the top of my head, I am at 
     work. The basic theory is simple, take 12VDC and chop it into pulses, 
     feed it into a step-up transformer, rectify it, and charge a 0.1uF 
     cap. To trigger, use a SCR in series with a coil primary. Then the SCR 
     is triggered by the points, whatever, then the cap dumps it charge 
     into the coil, about 300 volts or so. Also, MSD has a system that does 
     multple sparks using a cap. system.
     
     There are a lot of practical consideration that I skipped. If you need 
     the articles referenced I can try to look them up this weekend and 
     post them. I tried building one in 81 but it didn't work very well, 
     course I really didn't have a clue back then but that is another 
     story<g>.
     
     
     Terry Sare
     
     EMAIL: Terry_Sare at ccmail.us.dell.com 


______________________________ Reply Separator _________________________________
Subject: CD Ignition
Author:  owner-diy_efi-outgoing at coulomb.eng.ohio-state.edu at dell_unix
Date:    8/15/96 1:55 PM


Hi,
     
Has anyone have an article on the theory or even a schematic of a Capacitive 
Discharge Ignition.  In particular are they just stepping up battery voltage 
to about 300V and then switching that with a shorter dwell time or is there 
more to it?
     
Got to be able to crank my Briggs&Stratton Lawnmower engine down to -40 
degrees you know and at that temperature the batter is much less efficient.
     
Thanks,
     
John.
     
     
Pioneers are the ones, face down in the mud, 
with arrows in their backs.
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