How do Atom Computer Ignition modules work?

[garry-in-michigan]

[greg-o]

I put one of those in a old John Deere chain saw I have. It worked great. No more cleaning and adjusting the points. But have never tried it on an outboard motor. But I agree with the previous post. As engine rpm increases, so does voltage.

[debe]

Yes the voltage does rise, but the timing doesn’t appear to alter using a timing light.

[joesnuffy]

I have been studying this older thread and my question is for Gary. Does your diagram I posted here I don’t see the Mosorb diode 1N6303A used. Does your circuit need it or does the BD649 switching diode not need it? Is this the last circuit they came up with that folks should build if trying to do this?

Thanks,
Joe

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[debe]

joesnuffy, I am the person that originaly reverse engineered the Atom Ign module. Do not use a BD649 transistor as it wont last. As I cant post pictures here I have found that for reliability you need to use a 2SD1071 transistor & the 1N6303A Mosorb diode.

[joesnuffy]

" I am the person that originaly reverse engineered the Atom Ign module. Do not use a BD649 transistor as it wont last. As I cant post pictures here I have found that for reliability you need to use a 2SD1071 transistor & the 1N6303A Mosorb diode"

Thanks Debe for clearing that up. I am going to be building me a few. I got most the stuff I need minus the 2SD1071 and the 1N6303A Mosorb diode. I got to order them.

One question what is the silicone material you used for insulating the diode and where can I get it?? Also any tips??

Thanks,
Joe

[Pete]

How do these Atom units (and this RE circuit) compare to the Nova II units for points to electronic ignition ❓ Since Atoms are NLA and if the Nova II does the same thing why not use it instead of the built circuit ❓ The Nova II’s have been approved for use in APBA boat racing and they have made their way to the Yamato point ignition race engines and they work very well.

[joesnuffy]

I have used nova IIs on 2 of my omc 2 cylinder 2 stroke engines with brand new omc coils. I have had good results that way and ran one of those engines yesterday for over an hour at wot. Its a 5.5hp 1960 johnson.

Most everyone here has not had good results with nova II modules. Time will tell if the new omc coils will allow the nova II’s to hold up. I am guessing that older omc coils for whatever reason kill the nova II modules. That is a guess on my part but I am going to run those 2 modified engines this summer a lot to try and determine if that might be the case.

I am building my own atom modules because its an easy non-expensive way to put them in all my motors and leave the ignition coils that are already in my outboard engines in them and see how they hold up verses the nova II modules using new omc coils.

Atom modules hold up that is why I am building them.

Joe

[debe]

When I build a module I check first that is going to work, then I set them in 5Minute Araldite a 2 part epoxy type of resin.

[joesnuffy]

Thanks where do you get the silicone material underneath the transistor??

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