| 摘要 |
<p>PURPOSE:To reduce the power consumption of a magnetic sensor by exciting the sensor with use of burst waves which are made higher in amplitude for the first plural waves, and lower for the succeedings. CONSTITUTION:A magnetic sensor mounted on an unmanned carrier causes an excitation coil 2 to produce an AC magnetic field by supplying drive voltage pulses Vin to a driving source 1 and guides the carrier by detecting deviations from ferrite markers installed along the course of the carrier from the difference between detecting voltages induced in a right and left detecting coils 3 and 3'. When burst waves which are made higher in amplitude for the first plural waves as shown in Fig. (a) are supplied to the excitation coil 2 as the driving voltage Vin, the time during which the detecting voltages of the coils 3 and 3' reach a fixed level can be reduced as shown in Fig. (b). Therefore, the power consumption can be reduced when the duty ratio of the burst waves is set smaller.</p> |
