Electronic Ignition Questions

[Arc]

Try Beamspark ignition...................

[Mark A]

Spaceman, that would be a very useful contribution indeed but I suspect the black box might require a brief trigger pulse to work and all points can do is switch a relatively long-lasting voltage on or off. I've asked Pazon who may see a way through.

Ark, thanks, that's a useful looking system but it's only a spark-booster and again requires the mechanical advance-retard.

[Spaceman]

After a bit of research, I now know how the B-B ignition module functions internally which will be more or less the same as for the Pazon Sure Fire. It is triggered by the negative going sine wave generated by the two trigger coils which the module then integrates to generate a voltage bias that gives the increase in ignition advance as the revs rise. It is likely that this bias is a function of both the increase in amplitude of the trigger signal as the revs rise (Faraday's Law of Induction) as well as the increasing frequency of these sine wave negative going pulses (number of pulses per second).

It's possible that with a constant amplitude trigger signal (from mechanical points), the ignition module may only generate a limited amount of advance. Without testing it, it is difficult to predict the answer. At the moment, I've found my B-B ignition module and the rotor plate but I can't find what I've done with the stator containing the trigger coils. As soon as I've found the stator plate, I'll test that side of the system to see what sort of trigger signal is generated and I should then be able to test the ignition module and measure how much advance is being generated.

[Mark A]

That observation fits with what Pazon told me and I had suspected before, that signal from the magnetic pickups varies with rotational speed and plays an active  part in forming the advance curve.

They said, "It’s actually a function of all the main parts (rotor, trigger and module).
The module is the ‘brains’, that controls the timing based on the signal (rotation speed) coming from the trigger assembly."

Here's a link to Runtronic's explanation http://www.jeperformance.biz/runflux.htm

[Spaceman]

The actual ignition advance is generated within the ignition module but it relies on the characteristics of the trigger signal - as a minimum, the trigger signal is telling the ignition module what speed the engine is rotating at!

I've just found the stator board containing the two pick up coils. I'll test it tomorrow and see what signal amplitude it generates. Once I've determined this, I should then be able to fire up the ignition module and see how this behaves.

[Spaceman]

I will confirm by a test later but I am now certain that the B-B ignition module relies on the amplitude of the sinusoidal voltage or current from the two trigger coils to vary the ignition timing within the ignition module. The trigger coil output level will increase linearly with rpm and the ignition module uses this to provide a bias to the point at which it triggers the output current to the ignition coil(s) on the sinusoidal waveform from the trigger coils.

Unfortunately, this means that it is impossible to trigger the B-B ignition module (or the Pazon Sure Fire) and use its advance/retard feature from a mechanical set of points.

[Spaceman]

I've just been looking at how the Lucas Rita electronic ignition worked. This used a specially shaped reluctor/rotor that changed the shape of the waveform from the pickup coil as the rpm increased changing the trigger point inside the ignition module thereby advancing the ignition.

Essentially, whether it is the Rita, B-B or Pazon ignition module, they all rely on using the changing shape or amplitude of the trigger waveform with rpm to alter the exact point at which the current to the ignition coil(s) is triggered. As indicated, they will only work as a complete system and none can be made to work with contact breaker points.