| Popis: |
For some time now devices have existed for automatically plotting the Nyquist amplitude phase characteristics of feedback devices where the significant frequencies were below 100 cycles. These devices were largely electro‐mechanical in nature. There has been a need for a device to plot the Nyquist amplitude phase characteristics of devices which operate at frequencies where electro‐mechanical techniques are no longer usable. The application of the Nyquist criteria to audio amplifiers, and more particularly to the complex feedback paths of modern hearing aids, is discussed as a useful method of analyzing their operation and synthesizing improved designs. For this purpose an electro‐mechanical Nyquist plotter has been constructed which automatically plots the amplitude phase characteristics of feedback devices in the audio frequency range. Details of this device are explained. |
