Optical Theremin

As part of the National Instruments Tinker, Learn, and Do Engineering with NI myDAQ course ware, the hands on experiments demonstrate the wide range of possibilities of using NI myDAQ hardware. The 10 lab experiments cover a wide range of topics including analog and digital circuits, sensors and signal processing of audio sound tracks. View all o
Optical Theremin - schematic

f the labs for the Tinker, Learn, And Do Engineering With NI myDAQ course ware. In the 1950s and 1960s, a new spooky background sound was introduced to fans of ScFi and horror TV shows and movies. It was not a new sound but a rebirth of the Theremin invented in 1928 by Professor Leon Theremin using 1050s electronics (Fig. 1). The Theremin was the first electronic musical instrument. It had two antennae which were part of resonant RLC oscillators. When you placed you hand near an antenna, the electric field was disturbed, resulting in a shift of the resonant frequency. One antenna controlled the frequency or pitch, while the other antenna modified the amplitude of the sound. The Theremin now has a cult following, and you can see and hear the early sounds in some of the references. This lab uses myDAQ and two optical sensors to build an optical Theremin with its own unique sound. One hand moves over a photodiode to change the pitch. The other hand moves over a second photodiode to change the amplitude. There is a lot of scope in this project to make your sound unique and to let your creative juices flow. Download the files aboveto access the courseware pertaining to this lesson that illustrate how the mDAQ can be used with NI LabVIEW covering a range of tools from introductory level exercises to design challenges. A photodiode (when radiated by a light source) generates a very small (microamp) current. The signal level can...

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