The plasmatic pulsar device (PPD) was a direct-fire plasma weapon developed by the Interstellar Concordium. When the weapon locked onto a starship, it would deliver multiple successive plasma volleys against the target. Due to the way damage affects ships, smaller individual volleys were more likely to damage weapons and power systems than their damage equivalent in a single volley. This meant that the ISC were able to effectively strip away the weapons of many of their targets.
While the PPD can be overloaded, the effect is to generate additional pulses, rather than to increase the damage of each pulse the technology creates. (TOS video game: Starfleet Command Volume II: Empires at War)