ME 360 Midterm: ME 360 Alabama Test3 S09
Document Summary
Piezoelectric accelerometers work by converting the force applied to a known mass (a=f/m) into a resistance change measured by a wheatstone bridge. Pwm stands for pulse-width-modulation - a way to vary the speed of an electric motor. The speed of an ac motor depends only on input frequency and the number of poles. Potentiometers and lvdt"s are used to measure linear displacement. Accelerometers are frequently used to measure low frequency vibrations ( < 100 hz). When used as a tachometer, a dc motor will produce a voltage that is proportional to the angular position. Short answer questions - use the space provided for written answers: [6] the setup below is used to measure angular velocity of a shaft. In a 0. 80 second period, a total of 375 pulses are counted. 0 1 2 3 4 5 6 7 8 9 372 373 374 375.
