Abstract: A polyphase line voltage regulator which uses polyphase pulse saturable ferroresonant reactors in series with three separate and equal input chokes. The line voltage regulator is particularly suitable for computer operations which impose a variable current demand on the power source. The input chokes are directly coupled with an unregulated a.c. source and are provided with controlled non-linearity. LC tuned circuits inhibit the second and third harmonics from the regulated a.c. voltage. An isolation transformer is connected across the polyphase pulse saturable ferroresonant reactors and delivers a voltage regulated a.c. output voltage to a load.