Comments on “Limitations of the Describing Function Methodâ€

Recently an example to illustrate the misuse of the describing function method was pointed out.1 It is the purpose of this correspondence to show that the order of the harmonic for which there is an appreciable output is quite high for the same example. Further, it is pointed out that the fifth harmonic is not the harmonic with the largest amplitude, but it is the third harmonic. Incidentally, a simulation under CSMP on the digital computer showed that the radian frequency of the limit cycle is about ten percent less. Copyright © 1977 by The Institute of Electrical and Electronics Engineers, Inc.