Abstract: Piezoelectric ceramic loads work through the principle of inverse piezoelectric effect, and the driving voltage of the load often adopts AC output. By changing the voltage amplitude of the AC output, the swing amplitude control of a cantilever beam based on piezoelectric ceramics can be achieved, often used in engineering fields such as turbulence and active heat dissipation. If analog gear control is used for amplitude modulation control, there will be high switching current stress, limited optional swing, and high cost. Proposes a virtual isolation digital controlled PWM duty cycle regulation method, which achieves stepless regulation of output voltage by controlling the current size of the bus voltage feedback loop, and also solves the problem of high current stress during switching. This scheme realizes that the peak to peak value of AC output voltage can be dynamically adjustable between 12 V and 430 V at 12 V input, with low cost, and also analyzes the overall conversion efficiency.

Key words: Piezoelectric ceramic, Virtual isolation, Dynamic stepless voltage regulation