| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of detecting the abnormality of a coil in use of a three-phase linear motor. <P>SOLUTION: A current flowing through two or more coils of W phases is detected by the voltage across a resistor R1, and it is amplified with an operational amplifier OP1, and is inputted into a divider OP2. On the other hand, voltage applied to two or more coils of W phases is detected, and it is divided with resistors R6 and R7, and is inputted into the divider OP2. The divider OP2 divides the inputted partial voltage value by the output of the operational amplifier OP1, and outputs values corresponding to the resistance values of two or more coils of W phases. A controller switches on a switch SW1 when the mobile velocity of a moving member becomes zero. Thereupon, the output of the divider OP2 is amplified with an operational amplifier OP3. Two reference voltages are severally inputted in advance into two comparators CP1 and CP2. The output of the operational amplifier OP3 is inputted into these two comparators CP1 and CP2, and is compared with the reference voltages, and when it is outside the range between the two reference voltages, abnormality output is made. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
