If I have four 100Hz sinewaves with a 0, 90, 180, 270 degree phase relationship and apply one each to four coils in a circular array, what is the actual frequency of the applied wave?
I know the rotational speed will be 100Hz, but is there a 400Hz field component?
Ken Sutton
No. If any of the core materials were likely to saturate, you might get some odd harmonic content - from symmetrical non-linear distortion
- but getting any 400Hz component seems very unlikely.
-- Bill Sloman, Nijmegen
The simple trig formula for the linear addition of sinusoids will give the proper answer.
Bob
There is a nice animation of this about halfway down this page.
Ken
Are you concerned with time behavior? Then no, no 400 Hz would be generated. Or, is this about the field in the middle of the array? That would depend on any pole pieces you use in addition to the coils. A rotor inside a four-pole stator could have any magnetic-material nonlinear response, including a combination of rotation and saturation that would give some
400 Hz induction.Ken Sutton schrieb:
Hello,
the same 100 Hz. By the way, you only need two sinewave signal with 90 ° phase shift, the rest is done easily with proper connection to the four coils. 270 degrees phase shift result from the 90 ° signal connected with both ends changed.
Bye
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