An analytical basis for the design of a ferroresonant transformer is developed. A normal ferroresonant transformer without any control winding is considered, and piece-wise linear approximations are assumed for the magnetization curve of the material. An equivalent electrical circuit for the secondary of the transformer is obtained, and the basic concept leading to the equivalent circuit is also discussed. The circuit is then analyzed, utilizing linear circuit theory, for both no load and resistive load assuming a square wave input (as in the case of dc to ac conversion). The results obtained from the analysis of the equivalent circuit are utilized in deriving expressions for 1) the number of primary turns N
pfor a given input voltage, 2) the number of secondary turns N
s, 3) the value of the capacitance

required for the maximum power output, and 4) the relation between the capacitance and the ratio of air gap area to air gap length. A set of curves is provided to facilitate the choice of capacitance.