| 摘要 |
PURPOSE:To insert a resonance filter and form the bypass of the resonance filter automatically by a method wherein the resistance values of two resistors are so selected as to be neglected compared with the resistances of peripheral circuits in both the situations wherein the resonance filter is attached and the resonance filter is detached. CONSTITUTION:When a resonance filter 4 is connected to a speed feedback control loop, the resonance filter 4 is connected in parallel with two resistors R1 and R2 which are connected to the control loop in series and, at the same time, the common node of the two resistors R1 and R2 is grounded. When the resonance filter 4 is not connected to the speed feedback control loop, the two resistors R1 and R2 only are connected in series to the speed feedback control loop. That is, in both the situations wherein the resonance filter 4 is attached and the resonance filter 4 is detached, the resistance values of the resistors R1 and R2 are so predetermined as to be neglected compared with the resistances of peripheral circuits. |
