Abstract: A static inverter has a chopper transistor between a unidirectional source and the inverter load current carrying semiconductor switches, time ratio controlling means including a constant frequency oscillator for modulating the chopper at the constant oscillator frequency and for regulating the width of pulses conducted by the chopper as a function of the magnitude of an analog command signal, means for modulating the inverter semiconductor switches at a frequency which is a function of the analog command signal to establish the inverter output frequency, and means for synchronizing the switching of the chopper to the inverter output frequency so that the chopper is reset at the beginning of each half cycle of inverter output frequency.