Automatic analyzer and control method thereof

An automatic analyzer comprising:

• a piezoelectric element configured to generate ultrasonic waves for stirring a sample and a reagent;
• an amplifier configured to drive the piezoelectric element;
• a relay switch provided between the piezoelectric element and the amplifier;
• and
• a control unit configured to control the amplifier and the relay switch, wherein
• the piezoelectric element includes a first piezoelectric element and a second piezoelectric element,
• the relay switch includes a first relay switch provided between the first piezoelectric element and the amplifier, and a second relay switch provided between the second piezoelectric element and the amplifier,
• the first relay switch includes a positive voltage-side switch that turns on and off a connection between a positive voltage-side electrode of the first piezoelectric element and the amplifier, and a GND-side switch that turns on and off a connection between a GND electrode of the first piezoelectric element and the amplifier,
• the second relay switch includes a positive voltage-side switch that turns on and off a connection between a positive voltage-side electrode of the second piezoelectric element and the amplifier, and a GND-side switch that turns on and off a connection between a GND electrode of the second piezoelectric element and the amplifier,
• when the first piezoelectric element is driven, the control unit turns on the positive voltage-side switch and the GND-side switch in the first relay switch, and turns off the positive voltage-side switch and the GND-side switch in the second relay switch, and
• when the second piezoelectric element is driven, the control unit turns on the positive voltage-side switch and the GND-side switch in the second relay switch, and turns off the positive voltage-side switch and the GND-side switch in the first relay switch.