| 摘要 |
A magnetism detecting device that can achieve a high gain and can also detect magnetism without being affected by an offset voltage, and a banknote identifying apparatus that includes such a magnetism detecting device are configured. A magnetism detecting device (101) includes a magnetic sensor (1) that is provided with a resistive voltage divider circuit including a magnetoresistive element (Rl), an alternating current amplifier circuit (20) that subjects an output signal of the magnetic sensor (1) to alternating current amplification, an integrating circuit (30) that integrates an output signal of the alternating current amplifier circuit (20), and a differential amplifier circuit (40) that subjects the output signal of the alternating current amplifier circuit (20) and an output signal of the integrating circuit (30) to differential amplification. |
