Two Antiparallel ignition coils

[Jeg]

Hi to all

I have seen in many sites, drivers for antiparallel ignition coils. This topology supposed to produce opposite magnetic fields which doubles the output power. But there is something that i don't quite understand. Ignition coils have an internal diode at the HV output, so they produce only positive peaks. How those peaks can be opposite?

In the schematic there are two ignition coils in an antiparallel connection. Waveforms 1 and 2 are with each output without the diode. Waveform 3 is the real output between the HV outputs of the coils.
Do i miss something?

Thanks
Jeg 

[Magluvin]

Hi to all

I have seen in many sites, drivers for antiparallel ignition coils. This topology supposed to produce opposite magnetic fields which doubles the output power. But there is something that i don't quite understand. Ignition coils have an internal diode at the HV output, so they produce only positive peaks. How those peaks can be opposite?

In the schematic there are two ignition coils in an antiparallel connection. Waveforms 1 and 2 are with each output without the diode. Waveform 3 is the real output between the HV outputs of the coils.
Do i miss something?

Thanks
Jeg

Seems interesting. But the output diodes confuse me. They only allow one direction on the outputs and they are the same direction. I dont see how they conduct with each other, unless it is counting on reverse breakdown of one of the diodes, or both alternately if there is oscillation between pulses to the primary of the coils.

Havnt seen this circuit before.  Thanks for showing

Mags

[Jeg]

Thanks for the reply Mags. Perhaps are some ignition coils that the diode can be extracted so to reverse it. Anyway, i just wanted to be sure that i didn't forget my electronics lessons at school. 

ps. I really can not understand their mania to put internal diodes at ignition coils and tv flybacks! 

[SeaMonkey]

It is indeed very common to find diodes built
into flyback transformers; but ignition coils?

Unless this is something very new I've not
encountered it yet.  Spark plugs are really
not polarity sensitive.

[Magluvin]

Maybe I was misunderstood.  There are 2 diodes shown on the schematic on the outputs. I agree, there should not be any in the coils. Its just that the diodes are biased for 1 way and both are in the same direction, but the circuit has the coils operating out of phase, so only 1 coil at a time can deliver to ground?  It looks as though the 2 outputs are meant to be the output. Its a simple enough circuit to try with or without diodes or even reversing one or the other. But what are ya gunna do with all that lightning? 

Mags