| 摘要 |
PURPOSE: To measure the starting voltage and fluctuation in rotation of a three- phase motor accurately by varying the drive voltage while fixing the frequency thereof at a predetermined value. CONSTITUTION: A DC voltage is fed from a variable power supply 8 to a DC power supply input terminal 1 thence fed, as a drive voltage, to an output drive stage 2 which feeds a three-phase drive signal to the winding 4U, 4V, 4W of a motor through terminals 3U, 3V, 3W. A rotor 5 is arranged, alternatively, with parts 5N, 5S magnetized with N pole and S pole, respectively. The output drive stage 2 generates a three-phase waveform at a frequency based on an oscillation signal from a self oscillation circuit 7 having frequency fixed to a relatively low value. The winding 4U, 4V, 4W is connected with nothing. Output potential of the variable power supply 8 is then measured by means of a voltmeter 9. With such method lowest starting voltage of the motor can be measured accurately. |
