The 50 kHz signal generated by this circuit is applied to a low impedance inductive transducer. A power PNP transistor like the TIP32 can be used in the driver stage sourcing some watts to a 4 to 8 Ω transducer. The frequency can be changed by the capacitor C2. Values in the range between 1 nF and 4n7 can be used. Current drain is about 500 mA, but more power can be obtained using a power MOSFET. Figure bellow shows the simulation in the MultiSIM. The waveshapes for the signal in the transducers are displayed by the virtual oscilloscope found in the MultiSIM.
To download the simulation files and Netlist - click here (ni0008.zip)