As shown in
a sensor unit 20 including a Hall sensor 21 which inducts a magnetic field and produces square signals on the principle of Hall effect, wherein the Hall sensor 21 produces “Hi” signals when it inducts a magnetic pole N while produces “Low” signals when it inducts a magnetic pole S;
a signal display unit 30 which includes an amplifying transistor 31 for transmitting signals generated by said sensor unit 20 to a display component 32 and driving the display component 32 to reflect the alternation of the signals; wherein the display component 32 is at least one LED component which is darkened when sensor unit 20 produces “Hi” signals and is brightened when sensor unit 20 produces “Low” signals; and
a signal output unit 40 having a bipolar op amplifier 41 which comprises an op amplifier 42, a power source 43 with reference voltage and a amplifying resistance 44 for transferring signals from said sensor unit 20 into a set of Z and /Z signals for measuring usage of the machine tool. As shown in
Referring to
Moreover, since the LED component 33 is darkened when sensor unit 20 produces “Low” signals and is brightened when sensor unit 20 produces “Hi” signals, as the sensor 10 moves along the surface of the scale 50 widthways within the magnetic field of the scale 50, the LED component 33 twinkles corresponding to the alternation between NS polarities of the scale 50 it detects. Thus, an operator can confirm that the magnetic sensor 10 works normally.
Although a particular embodiment of the invention has been described in detail for purposes of illustration, it will be understood by one of ordinary skill in the art that numerous variations will be possible to the disclosed embodiments without going outside the scope of the invention as disclosed in the claims.