| 摘要 |
PURPOSE:To realize motor control corresponding to the load characteristics thereof by providing a circuit for regulating the output current of a current mirror circuit with a source follower circuit comprising a FET and applying a control voltage on the source follower circuit thereby controlling the oscillation frequency at an oscillating section. CONSTITUTION:Upon application of a control voltage Vi on the gate, a MOSFET 26 feeds a drain current corresponding to the control voltage Vi. Consequently, a circuit having an impedance corresponding to the control voltage Vi is formed when viewed from a terminal 22, and the output current I1 from a current mirror circuit section 20 varies in response to the magnitude of the impedance. When the output current I1 is fed, as a control current, to an oscillating section 30, the oscillating section 30 oscillates with a frequency corresponding to the control current. An oscillation frequency signal is then taken out from an output terminal 34 and delivered, as a control signal A, to a servo motor control section 3. According to the constitution, starting, braking and reverse rotation control corresponding to the load characteristics of a motor 1 can be realized. |
