A signal generator has a generator output. The signal generator is configured to generate first and second signals at the generator output. The first signal has a first frequency, and the second signal has a second frequency. Switching circuitry has a circuitry input and a circuitry output. The circuitry input is coupled to the generator output. The circuitry output is adapted to be coupled to an ultrasonic transducer mechanically coupled with a surface. The switching circuitry is configured to: provide the first signal to the ultrasonic transducer at the first frequency to reduce a fluid droplet on the surface from a first size to a second size; and provide the second signal to the ultrasonic transducer at the second frequency to reduce the fluid droplet from the second size to a third size.

A system (1) for generating hydrogen gas comprises a reaction vessel (101) containing an aqueous solution (102) and a cathode (105) and an anode (107) each positioned at least partly in the reaction vessel (101). The system (1) comprises first and second ultrasonic transducers (215-220) which emit ultrasonic waves in the direction of the cathode (105) and the anode (107) respectively. Each ultrasonic transducer (215-220) is driven by a respective transducer driver (202) to optimise the operation of the system (1) for generating hydrogen gas by sonoelectrolysis.

Methods and apparatus for ultrasonic lens cleaner using configurable filter banks are disclosed. In certain described examples, the methods and apparatus can expel fluid from a droplet on an optical surface using an ultrasonic transducer mechanically coupled to the optical surface and having first and second resonant frequency bands.

Methods and apparatus for using two stage ultrasonic lens cleaning for water removal are disclosed. An apparatus can expel fluid from a droplet on an optical surface using an ultrasonic transducer mechanically coupled to the optical surface and having first and second resonant frequency bands. A signal generator can generate a first signal including a first frequency to be coupled with the ultrasonic transducer mechanically coupled to the surface, and can generate a second signal including a second frequency to be coupled with the ultrasonic transducer mechanically coupled to the surface. Switching circuitry can activate the ultrasonic transducer at the first frequency to reduce the droplet from a first size to a second size, and to activate the ultrasonic transducer at the second frequency to reduce the droplet from the second size to a third size.

A method and apparatus for delivering energy during a surgical procedure such as phacoemulsification is provided. The method and apparatus include applying energy during at least one pulsed energy on period, typically sufficient or intended to rapidly induce and beneficially employ transient cavitation. Applying energy during the pulsed energy on period comprises applying energy during a first high energy period, and applying energy during a second nonzero lower energy period.

A method and apparatus for delivering energy during a surgical procedure such as phacoemulsification is provided. The method and apparatus include applying energy during at least one pulsed energy on period, typically sufficient or intended to rapidly induce and beneficially employ transient cavitation. Applying energy during the pulsed energy on period comprises applying energy during a first high energy period, and applying energy during a second nonzero lower energy period.

The present invention relates to a driver device (40) for driving a load (52) having a plurality of separate capacitive load elements (52), in particular an ultrasound transducer having a plurality of transducer elements (52), comprising: input terminals (44, 46) for connecting the driver device (40) to power supply (48); a plurality of output terminals (50) each for connecting the driver device (40) to one of load elements (52), a first controllable switch (54) connected to a first of the input terminals (44), and a plurality of driving elements (42) each having a second controllable switch (60) and a resistor (58) connected in series to each other, wherein each of the driving elements (42) is connected in series with the first controllable switch (54) and to a second of the input terminals (46), and wherein each of the output terminals (50) is connected to one of the driving elements (42) for powering the load elements (52).

A method and apparatus for delivering energy during a surgical procedure such as phacoemulsification is provided. The method and apparatus include applying energy during at least one pulsed energy on period, typically sufficient or intended to rapidly induce and beneficially employ transient cavitation. Applying energy during the pulsed energy on period comprises applying energy during a first high energy period, and applying energy during a second nonzero lower energy period.

An ultrasound system includes a transmit-receive switch. The transmit-receive switch includes a combined transmit-receive and return-to-zero (RTZ) path. The combined transmit-receive and RTZ path includes a transistor with a first current terminal, a second current terminal, and a control terminal. The second current terminal of the transistor is coupled to a ground node via a first switch and is coupled to a receive node via a second switch. The ultrasound system also includes a receiver front-end circuit coupled to the receive node.

In the IC card, the control circuit includes the microcomputer generating the square-pulse drive signal and the transistor boosting the square-pulse drive signal generated at the microcomputer, and the drive signal boosted by the transistor is used as the drive signal for driving the piezoelectric element. Since the drive signal generated by the transistor is boosted more than the drive signal generated at the microcomputer, the improvement of the vibration intensity of the piezoelectric element can be implemented.