Here's another perspective on the fields on the coils that has recently occurred to me; related to my post here:
http://www.ionizationx.com/index.php/topic,2946.msg27337.html#msg27337First off, let's look at the initial pulse on the primary core. It will create a field on the core creating a potential difference across the L2 coil. Now the one thing that they are not seeing is that this also creates a voltage potential across the L1 and secondary coils (which are in series) also at the same time since they are in parallel with L1. This means that the voltage created on L2 will develop a field on the secondary core (which have L1 and the secondary connected in series) at the same time as L2 purely because of the voltage potential developing across L2.
The secondary and L1 coils on the secondary core behave almost like a transistor. Once the voltage from the L2 on the primary core energizes and creates a voltage potential across the secondary/L1 the current from the collapsing primary core can now flow through these coils in the direction that the diode will allow. This is because the field already exists from the applied voltage and the current is no longer needed to create the field. BUT on the off pulse on L2, the field on the secondary core will be reluctant to collapse because of the way the coils are wired which opposes the fields collapse. As such, the next voltage pulse from L2 only increases the field on the secondary core, maintaining a constant increasing step up voltage on this side of the WFC.
This is just a theoretical way to look at this. I don't know for sure if it works this way.
However, the amount of current that will be able to flow through the secondary/L1 coils is dependent on 3 things:
1. The winding ratio between the 2 coils
2. The amount of current induced on the primary core.
3. Any other resistance in the VIC that will restrict the current
Equation to solve for mutual inductance is LT = L1 + L2 ± 2M