Proposed amplifier has direct three-phase 400V power supply which consists only of diodes and uses neither filtering capacitors nor transformer. Proposed amplifier consists of 3 modules. The first module is a conventional Class-D digital audio amplifier, which can work on high voltage supply. The second module is a simple 3-phase diode rectifier which rectifies alternating voltage of a 400 V three-phase system. The third module is a negative feedback system that nearly eliminates the ripple voltage in the output signal. With the help of the third module (negative feedback for the power supply ripple) the first module (conventional class-D amplifier) actually behaves as it has power supply with the voltage equal to DC component Vdc of the rectified three-phase voltage.
This paper costs $33 for non-members and is free for AES members and E-Library subscribers.