Piezoelectric element driving circuit

A pump comprising:

• a signal generation unit that generates a sinusoidal signal;
• a transformer that receives the sinusoidal signal generated by the signal generation unit on a primary side, and includes a first terminal and a second terminal on a secondary side and a third terminal led from a midpoint between the first terminal and the second terminal;
• a piezoelectric element including a first electrode connected to the first terminal;
• a first capacitor including a first electrode connected to a second electrode of the piezoelectric element and a second electrode connected to the second terminal;
• a second capacitor including a first electrode connected to a connection point of the second electrode of the piezoelectric element and the first electrode of the first capacitor;
• a first diode including a cathode connected to a second electrode of the second capacitor and an anode connected to the third terminal;
• a second diode including a cathode connected to a connection point of the second electrode of the second capacitor and the cathode of the first diode, and an anode connected to a connection point of the first electrode of the piezoelectric element and the first terminal;
• a third diode including a cathode connected to the connection point of the first electrode of the piezoelectric element, the first terminal, and the anode of the second diode, and an anode connected to the connection point of the second electrode of the piezoelectric element, the first electrode of the first capacitor, and the first electrode of the second capacitor;
• and
• a space a volume of which changes by driving of the piezoelectric element, the space including an inlet and an outlet of a fluid.