An all-solid-state pulser for the excitation of repetitively pulsed gas lasers is described which uses thyristor switching followed by a ferrite core pulse transformer and a four-stage pulse compression system using DC biased ferrite magnetic switches. An analysis of energy losses in the complex high voltage circuit is made, and an energy conversion efficiency of 73% overall is shown to be obtained, using commercially available ferrite materials. Interfacing of the circuit to the TEA CO₂ laser is discussed.