A simulation of a power generator that powers a shield taking constant hits from some kind of bombardment.

The shield dome requires constant power to run. It can create a field with a maximum strength. Impacts will weaken the shield, and the shield will return to full strength.

Emitter is powered by a capacitor Capacitor can hold enough charge to power the shield for two seconds If the capacitor reaches zero, the shield turns off Capacitor is powered by a battery The battery is charged by generators

Perhaps a weapon could overcharge the capacitor and make it explode

Batteries are connected in parallel.