Experimentation with polyphasic voltages is greatly simplified when microcontrollers are used to generate multiple square waves with fixed phase offsets. Each square wave is sent through a simple second-order Sallen–Key filter to produce an approximately sinusoidal voltage signal. The microcontroller allows the reproduction of split-phase and three-phase voltage relationships, mirroring those commonly distributed on the North American power grid, at safe voltage levels.
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C language source code available for download at ⟨http://www.chemphys.armstrong.edu/baird/tiny13_3phase.c⟩.
8.
Compiler/editor available from ⟨http://winavr.sourceforge.net/⟩. A substantial online community, including discussions and tutorials focused on the Atmel AVR microcontrollers, can be found at ⟨http://www.avrfreaks.net⟩.
© 2010 American Association of Physics Teachers.
2010
American Association of Physics Teachers
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