It is inherent in any switching action involving fast times that the switch, not being a perfect device, will change the input signal. In many instances this will not be imporant, but for other applications it may prove to be detrimental to the performance of the circuit. One such case is the circuit of a signal switched through a transformer to a load such as a spark gap. It is convenient to know the optimum performance obtainable, as well as how the circuit parameters may be varied in order to optimize the circuit. The solution for a ramp function type of switching between a voltage source and the primary of a pulse transformer is presented. The analysis shows how pulse transformers may be designed with a maximum of tolerance to poor switching characteristics. (auth)