Timing and those little aftermarket electronic ignition modules

[Chris-PA]

I doubt there's a micro in those modules - it's not required for the basic circuit, so it could only be part of the trigger, and just having a micro wouldn't tell you when to fire. I'm sure the trigger could be implemented with a fairly simple analog circuit (designing analog circuits is what I do).

When the module on my McCulloch 3420 failed I saved it, and I'd like to decapsulate it and see what the circuit is and what failed. I need to figure out what will dissolve the potting compound. I'll bet it's a capacitor that failed.

 

[3000 FPS]

I doubt there's a micro in those modules - it's not required for the basic circuit, so it could only be part of the trigger, and just having a micro wouldn't tell you when to fire. I'm sure the trigger could be implemented with a fairly simple analog circuit (designing analog circuits is what I do).

When the module on my McCulloch 3420 failed I saved it, and I'd like to decapsulate it and see what the circuit is and what failed. I need to figure out what will dissolve the potting compound. I'll bet it's a capacitor that failed.

Put a coil on the gate of an SCR and you have a trigger. The SCR then discharges the cap. Not a microprocessor. They are not going to make these things anymore complicated than necessary. You design analog circuits so you would know what I am talking about. For the most part I think you have it right.

 

[kz1000]

I did a 031 last week and the chip seemed to retard the timing some. Is it possible to have the two wires to the chip backward and cause this? I changed nothing else. Thanks!

 

[kz1000]

oops! didn't see how old this was.

 

[Brufab]

I did a 031 last week and the chip seemed to retard the timing some. Is it possible to have the two wires to the chip backward and cause this? I changed nothing else. Thanks!

Yes it can happen. And I'm gonna try a chip on an old Remington. I think they say to start with negative ground 1st.