Abstract: A polyphase variable frequency inverter with output voltage control provides a polyphase AC output from a constant potential DC supply, and comprises a chopper circuit and an inverter circuit. The chopper circuit further comprises a silicon controlled rectifier in parallel with a reverse biased diode. The anode of the silicon controlled rectifier and the cathode of the reverse biased diode are connected to the positive terminal of the constant potential DC supply while the cathode of the silicon controlled rectifier and the anode of the reverse biased diode are connected to the respective silicon controlled rectifiers and reverse biased diodes of the inverter circuit. The inverter circuit further comprises a plurality of branches, each including a first silicon controlled rectifier in series with a second silicon controlled rectifier, each such silicon controlled rectifier having in parallel therewith a reverse biased diode.