Assuming that there was a tear in the wrapping and the battery was inserted upside down,
wouldn't the case and the negative terminal be ground? The battery would short from the
tear in the wrap directly to the negative terminal. (assuming negative as ground.)
The switch isolates the ground from the coil with the positive terminal on the other side
of the coil.
With the switched open one way for a dead short to occur is through the wrapping
to the case directly to the positive terminal of the incorrectly inserted battery .
With a closed switch a Dead short can only occur when something by passes the coil
and completes a connection directly to the power terminals. If this occurs immediately
when the switch is closed that means the short is between the + side of the switch and
the negative side of the coil. As with my first scenario a dead short between the + side
of the coil would be evident as soon as the battery is inserted. Assuming the battery is
inserted correctly a tear in the wrap should have no affect if its not near the positive side
of the battery or the negative part of the tank.
In other word any short from the negative side of the switch or positive side of the coil
would be a dead short when inserting a battery.
Lastly with the switch open and a path to ground between the plus side of the switch and
negative side of the coil inserting the battery will cause the coil to fire continuously when inserted
correctly.
Theoretically in a mechanical mod it should not make a difference witch way the battery is
inserted. The switch and the coil do not care. So it gets down to when the short occurred.
If the battery is in perfect condition and the tank and tube are in proper working order
nothing should happen until the switch is closed. All things being equal current will just flow in the opposite direction.
Regards
Mike
Not the way that mod is made, as said it uses a "lift" switch to make the contact. The negative side of the battery is always in contact with the switch and it raises the battery to make contact with the positive pin. Set up that way, there is always contact with the negative and a tear in the wrapper wouldn't matter, as it would be grounded.
Put the same battery in upside down, now you have constant contact with the negative on the switch, but now it's positive. The tear in the wrapper is in contact with the side of the mod, that is supposed to be negatively charged from the switch. It creates a dead short, instantly.
Now take a Hades or Nemesis where the center pin on the switch has an insulator on it to shield the switch from making contact, nothing happens until you push the switch.
Does that help explain how that mod works better?