I am trying to determine what voltage and instantaneous current is available if using a spark gap in air or other gas. Comparable to an auto ignition. This will be DC current. There will be a main transformer like an automotive coil. It will be triggered in a CDI type layout where a capacitor will be discharged to cause the transformer primary side to have a lower voltage surge. The secondary will produce a potential of 40kv.
Discharge should last 1-1.2 milliseconds. The discharge will pass through a separate inductor coil. This coil has 14ga windings with approx 50uH inductance and 0.4ohms resistance. The circuit ends in a spark gap which allows the full voltage potential to be reached before the plasma forms and discharges the voltage.
This inductor coil just before the spark gap only needs to be powered for 1-1.2 milliseconds so its needed activation time matches the discharge time of the plasma arc.
How do I estimate the voltage drop over the arc time and the current over the same time.
Assuming the transformer is wound 1:1000 if input is 40 volt.
The spark gap to the right of L1 is used to ensure the coil voltage rises to 40kv before discharge begins. Activation of the secondary side of the transformer occurs when the mosfet is activated and drops the voltage in the voltage trap between rectifier D1 and capacitor C1. Values in the schematic are yet to be worked out.
So once the mosfet has dropped the voltage on the (+) side of the capacitor, it will create an electron flow through the primary side of the transformer. (primary side voltage may be increased prior to the voltage trap to a couple hundred volts instead of just 40 volts) This will create the needed voltage spike from the secondary to initiate the arc at the spark gap. When this reaches near 40kv there should be a glow event at the gap. Then as voltage drops and an arc begins, the current / voltage should find the equilibrium point until the charge is exhausted and voltage drops not in inverse to current and the arc stops conducting.
So for the time which the arc event is occurring and the current / voltage is more or less stable, what current and voltage can be expected?
In this model I wish to get 1 millisecond of usable current through the inductor coil L1. I would like to be able to calculate what this current should be.
Another slightly different version
Or another option using inductive discharge instead of capacitive discharge