No no no.
CDI and in fact how a stun gun works is to:
1) Bump up battery voltage to a few hundred volts
2) Charge a capacitor with the increased voltage
3) Discharge the capacitor through a high ratio coil
CDI does this all solid state but in a basic stun gun what happens is the capacitor is charged to X hundred volts using the charging circuit.
Then it discharges through the ignition coil by jumping a
very small gap, generally between two crossed metal strips separated by a thin insulator, less than 1mm gap.
Anyway that discharge completes one side of the high ratio transformer and results in the stepped up voltage (x100 maybe) on the other side.
I make these clips and no one looks at them
[youtube]
[/youtube]
That shows all the stages I just described.
Ignore the big numbers, just there for getting attention. More like 25k.