Hi.
Seen two kinds of these sparkers. The one with a trigger hammering a crystal :

And the squeeze ones :


How do the squeeze ones work ? Have one, produces 3 or 4 5mm spark arcs from start to end of the squeeze and also when releasing, not much effort to squeeze, definitively not hammering anything inside. Prefer not to dismantle it to inspect.

 

I have used the trigger type. They contain a cylinder of butane gas, When the trigger is pulled a spring loaded striker strikes a piezo cristal triggering a primary side of a transformer and the high voltage secondary arcs igniting the small gas floe.They work well for igniting the gas fireplace, my torchs and the BBQ pit. My wife buys them by the box for use around here. I can't comment on the squeeze type as I never used one.

Ron

 

Both types use stacks of piezo-ceramic material that generates large voltages when mechanically stressed.
Stacking them adds the induced voltage in series.

The snap-action type makes a single impulse, the squeeze type probably has larger piezo elements, the charge builds until the spark gap breaks down.

Cheap lighters all have snap-action, this must be the cheapest way to get a decent spark.