Transistor driven electronic ignition

[erik_w]

Hello!

I am not very experienced with Electronics, but recently gave building my own transistor driven iginition system a try and it worked really well!

The system I built was called Velleman K2543 and is really simple, but it is built for a single breaker contact and a distributor.

I would now like to try the same system on a dual breaker Contact / dual coil motorcycle, which means I have to either use two system completely in parallel or modify one to work with dual breakers.

Can anybody give me a helping hand on how to modify this system? I will attach a diagram of the orginial system.

 

[BrunoARG]

I don't understand the circuit since it has no indications about input and output terminals.

What's the circuit for? How does it do?

You could make a OR gate out of diodes and a pull resistor (to avoid noise). When one, other or either input are activated you can make your device turn on.

 

[crutschow]

If the two breakers each go to separate coils then you need two electronic systems.

 

[erik_w]

I don't understand the circuit since it has no indications about input and output terminals.

What's the circuit for? How does it do?

You could make a OR gate out of diodes and a pull resistor (to avoid noise). When one, other or either input are activated you can make your device turn on.

Hello!

Sorry for not clarifying the inputs and outputs.

1 - 12 volt from the ignition switch
2 - to breaker contacts, which create a path to ground when it is time to fire
3 - output to negative coil terminal
4 - ground

Yes, you would need at least two 2s and 3s to accommodate the dual coils and points. Is there a way to make a switching gate that fires one and the other coil alternatively, then you could use the single transistor to drive both coils?

 

[FvM]

Is there a way to make a switching gate that fires one and the other coil alternatively, then you could use the single transistor to drive both coils?

The question doesn't make sense. You have two breaker contacts and two ignition coils. The circuit isn't but an electronic switch, obviously you need two of it, which makes the minimal part count. Any attempt to combine both pathes will only increase the effort.

The answer is probably different in case of a CDI design where both channels can share a single HV supply. Or in any other case where some interaction between both channels exist. According to your posts, this isn't the case here. Trying to make a simple thing complicated?

 

[crutschow]

............................
Is there a way to make a switching gate that fires one and the other coil alternatively, then you could use the single transistor to drive both coils?

Not really. You would need a transistor and other circuitry in your "switching gate" so the complexity of such a scheme is likely more than just having two separate circuits.

 

[erik_w]

Thanks guys, I Think that you are right, the best solution would be to build two of these and run them side by side..