A pulsed energy weapon is any weapon that: * uses pulses of electricity to fire a projectile, or * operates by transferring electric current to its target. These weapons often use large capacitors to build up a charge which is released when the weapon is fired. Large high-end systems sometimes use compulsators which store energy using rotational inertia. Weapons which do not use projectiles, such as the stun gun and laser gun, do not need any ammunition other than a power source.