| 摘要 |
PROBLEM TO BE SOLVED: To detect magnetic field intensity having no relation to polarity of a magnetic field and complying with bipolarity by means of a simple structure while reducing current consumption. SOLUTION: This magnetic field sensor is provided with a Hall element 11 generating a Hall voltage in proportion to density of a passing magnetic flux, a voltage amplifier 12 amplifying an output voltage from the Hall element 11, a Schmitt trigger circuit 13 receiving an amplification signal from the voltage amplifier and outputting different output voltages according to its threshold, and a logic latch circuit 15 latching the Schmitt trigger circuit by receipt of an output signal from it. A switch circuit 14 reversing polarity of the amplification signal is arranged between the voltage amplifier 12 and the Schmitt trigger circuit 13. The Schmitt trigger circuit 13 reverses polarity of a hysteresis voltage deciding a reference value for the magnetic field intensity according to first and second synchronous signals serving as triggers for detection of the magnetic field.
|
