Control device for a piezoelectric ultrasonic actuator and method of operation

The device has a resonance inductor (Lp) in series with a bridge of four switches (P11,P12,P21,P22) and connected parallel to two end terminals (B1,B2). Each switch is associated to a diode (d11,d12,d21,d22) for blocking a current path in one direction of charging of the inductor. The bridge has two arms, each having two switches in series and a middle point connected to a piezo-electric actuator (Ai). An independent claim is also included for a method of implementing a device for controlling an ultrasonic piezo-electric actuator.