A Design of Excitation System for Fluxgate Based on Sine Wave

For solving the problem that a flux-gate sensor excited by the square wave would be disturbed by harmonics, a fluxgate excitation system with a sine wave excitation is presented. The system overall scheme, also with the detailed signal generator design, signal conditioning circuit, and the power amplifier circuit, are all given in this paper. At the same time, the key parameters of the excitation signal waveform, like frequency and current design performance indexes, are also presented. The analysis of the flux-gate sensor output waveform variation under different excitation is also illustrated. The results of the experiment show that: the proper frequency of the fluxgate under the sine wave excitation is 16 KHz measured by this system. With this excitation condition, the sensitivity of the flux-gate sensor is 110V/T, and the measurement range is ±500µT.