| 摘要 |
A coin detection system comprises an excitation coil (3), a radial magnetic gradiometer (5), an axial magnetic gradiometer (6), a signal excitation source (1), a drive circuit (2), an analog front-end circuit (7) and a processor (8). After the excitation coil (3) is excited by the signal excitation source (1) and the drive circuit (2), the excitation coil (3) generates an excitation magnetic field (10) parallel to the axial direction of a coin (4), and under the effect of the excitation magnetic field (10), the coin (4) generates an induced magnetic field (11) through eddies generated in the coin (4); the radial magnetic gradiometer (5) and the axial magnetic gradiometer (6) detect the magnetic field components of the magnetic field (11) in the radial direction and the axial direction of the coin (4), and the detected signal is transmitted to the analog front-end circuit (7) for amplification; the processor (8) processes and then outputs the amplified signal transmitted by the analog front-end circuit (7), and the material, design and color and denomination, etc. of the coin (4) are obtained according to the resonance amplitude, phase and other information of the output signal. |
