An apparatus for firing a non-lethal projectile comprises a body with an internal cavity. In one implementation a switching power supply and a linear regulator provide efficiency and rapid response. A logic operator receives the first to eighth counter signals x1-x8 and performs an operation, for example x1*x2x1*x3x1*x4x1*x5x1*x7x1*x8x2*x6x2*x7x3*x4x3*x5x3*x6x4*x5x4*x6x4*x7x4*x83x5*x7x7*x8x1x2x5x7, to generate a mask signal.