Are you proposing I am dealing with voltages in excess of that?

Maybe - it takes 1.1kV to jump 1mm at 1 bar pressure. You might have 9 bar pressure.

 

Maybe - it takes 1.1kV to jump 1mm at 1 bar pressure. You might have 9 bar pressure.

I think your confused about something, if you look at the waveforms posted above. I'm talking about 250 max

 

I think your confused about something, if you look at the waveforms posted above. I'm talking about 250 max

Really? Most sparking plug ignition systems work at 10kV and above. The voltage output from a magneto varies proportional to speed - that's why engines with magnetos are difficult to start.

 

Let's start from the beginning. My GENERATOR has a dual coil ignition, primary and secondary. The primary coil is induced by a magnet passing a core within the primary causing a current to flow which creates a magnetic field. This magnetic field is then intersected by the secondary coil, which overlaps the primary causing a greater current within. Now the research I've done suggests that the voltage in the primary coil gets to about 500v max. Now I can't be sure of the voltage I am getting but my scope suggests about -208v.

These ignition systems are somewhat different to your typical automotive ones.

 

Let's start from the beginning. My GENERATOR has a dual coil ignition, primary and secondary. The primary coil is induced by a magnet passing a core within the primary causing a current to flow which creates a magnetic field. This magnetic field is then intersected by the secondary coil, which overlaps the primary causing a greater current within. Now the research I've done suggests that the voltage in the primary coil gets to about 500v max. Now I can't be sure of the voltage I am getting but my scope suggests about -208v.

So it's a Low tension magneto. You said that there wasn't a lower voltage coil.
So the primary is about 500V, much the same as the voltage on an automotive ignition coil primary.
In that case, you should be able to short it out with a 800V triac/opto triac combination.

These ignition systems are somewhat different to your typical automotive ones.

They can't be that much different as they use the same sparking plugs, the same fuel and the same compression ratios.

 

So the primary is about 500V, much the same as the voltage on an automotive ignition coil primary.
In that case, you should be able to short it out with a 800V triac/opto triac combination.

But if if it doesn’t need to be turned on and off as he stated here:

BobTPH said:
It sounds like you want to turn the clamping on and off. Why?

No I very much need the clamping to stay in place

Then a simple diode does the same thing.

 

I am simply trying to ground the signal as to act for a kill switch for an ignition

I think he wants to stop the engine.

 

I think he wants to stop the engine.

Yes the same signal I am sampling is the one I want to short to ground.

 

I thought he was trying to pass on the positive part of the signal while clamping out the negative part, this after a resistor from the coil.

If indeed he is trying to stop the engine, then the switch must be directly across the coil. So why didn’t the transistor simply explode with 500V across it with no current limiting?

@dandy1: you need to explain better what you are trying to accomplish, and how it is connected to the ignition primary.

 

Yes the same signal I am sampling is the one I want to short to ground.

Do you expect it to stop the engine?

 

Do you expect it to stop the engine?

Yes

 

I thought he was trying to pass on the positive part of the signal while clamping out the negative part, this after a resistor from the coil.

If indeed he is trying to stop the engine, then the switch must be directly across the coil. So why didn’t the transistor simply explode with 500V across it with no current limiting?

@dandy1: you need to explain better what you are trying to accomplish, and how it is connected to the ignition primary.

The fact that the transistor hasn't exploded is that I simply think that there is not much energy as you might expect, please look at the waveform.
The signal is conditioned first by a reversed diode that blocks the positive voltage. At this point there is only negative pulses coming from the primary. How it's connected to the primary I have no idea as that part is not accessible. This wire(from which I get the signal) is dedicated solely for the purpose of grounding the signal to the chassis.
I want to short the signal to ground after the reversed diode.

 

Back in my motorhead days we opened the primary to kill an engine.