A method and apparatus for generating an AC voltage in a system frequency range from a DC input voltage. Two opposite-pole, pulse-width modulated (PWM) rectangular pulses having a high switching rate are applied to the primary winding of a transformer. Every pulse is modulated to correspond to a half-wave of the AC voltage to be generated. On the secondary side of the transformer, the impulses of both PWM pulse trains are rectified to create a pulse train of a single polarity, the pulse width modulation of which corresponds to subsequent half-waves of the AC voltage to be generated. The pulse train so obtained is periodically commutated at double the frequency of the AC voltage to be generated so that a PWM signal representative of the AC output voltage is obtained with respect to amplitude, frequency, and polarity.