Abstract: A wind instrument such as a saxophone, a clarinet or an oboe comprises touchpieces actuating covers via linkages. In this instrument, which can comprise two bodies side by side, shanks of the covers are fixed to the links by a removable fixing so as to allow the covers to be removed and aligned at least angularly with respect to the corresponding links.

Abstract: Systems, methods and apparatus for stabilizing resistance measurements in electroporation systems so as to achieve high-accuracy measurements, and for controlling the pulse duration, or time constant, of electroporation pulses. Circuitry is provided to accurately determine the resistance of a sample in the electroporation system, for example a sample provided in an electroporation cuvette. Additionally, a resistance control system is provided to automatically measure the resistance of a sample, determine a capacitance and determine a parallel add-on resistance that substantially provides a desired pulse duration (time constant) for an electroporation pulse.

Abstract: A DC motor drive circuit, includes a switching circuit that drives the coils of a small permanent magnetic DC motor. The drive circuit is preferably implemented in an integrated circuit device, such as a silicon CMOS device. Integrated into the same integrated circuit device is a magnetic sensor arranged to detect the position of the permanent magnet as it passes a defined point, or points, in its revolution, and control circuitry to derive the timing waveforms for driving the coils. The integrated power devices for driving the coils are also arranged to limit the rise and fall times of the applied voltages and currents so as to reduce or eliminate the generation of unwanted RFI. Additional circuitry is also integrated into the same integrated circuit device to derive the necessary power to operate the magnetic sensor, the control circuitry and the switching circuitry from the connections between the switching circuitry and the coils so as to remove the need for a separate power supply connection.