The Relationship of Magnetic Material Properties to the Operation of a Magnetic Sense Amplifier Device

摘要

The operation of a magnetic sense amplifier device is examined and a mathematical model is developed which relates the properties of the magnetic materials to the device operation. The magnetic materials utilized are 'square-loop' ferromagnetic materials in the form of torroidal cores. The development of the model is based upon the observed behavior of the magnetic material during device operation. The magnetic sense amplifier device is capable of the detection of a small signal current which occurs at a known instant in time. By means of capacitor current feedback during cyclic excursions of the B-H loop, a voltage on an output winding can be made to 'build up' in a parametron-like manner. The output voltage, after a known time delay, is of the polarity as the original signal current, but has significantly greater voltage than that due to the signal current. The analysis method used is the analysis of the waveforms during device operation. The waveforms are considered to be piecewise analytic functions of time. The capacitor charges and core flux linkages are matched at the boundaries of the intervals over which the analytic functions are valid waveform representations. The material properties which are significant during the time when amplification takes place are characterized in terms of the S-Curves, which are defined in this work. A circuit 'gain' is defined in terms of the flux linking an output winding. This 'gain' is found to depend on the material properties as determined from the S-Curves, the circuit element values, the drive pulse widths and the drive pulse amplitudes. Experimental 'gain' data given confirms the theoretical model. (Author)