| 摘要 |
PURPOSE:To attain measurement of loop gain without disconnecting a servo circuit by grounding the 1st resistor set between an error amplifier circuit and a drive amplifier circuit by means of the 2nd resistor and supplying a disturbance signal to the 1st resistor to obtain the loop gain. CONSTITUTION:A resistor 5 is connected between a drive amplifier circuit 1 and an error amplifier circuit 3 of a servo circuit, and connection terminals 6a and 6b are set at both ends of the resistor 5. For measurement of loop gain of this servo circuit, a resistor 7 is provided to the terminal 6b and grounded. At the same time, a disturbance signal VG is supplied from a disturbance signal source 8 for measurement via a resistor 9. Then the voltage VY between the terminal 6a and the ground is measured together with the voltage VX between the terminal 6b and the ground. Thus it is possible to obtain open and close loop gains GO and GC from both voltages VY and VX as well as resistance values of resistors 5, 7 and 9 without disconnecting the servo circuit. |
