| 摘要 |
PURPOSE:To speed up a pull-in response time and to record with less recording position drift, by connecting parallelly diodes different in direction each other to the capacitor of a phase compensation circuit in a phase control circuit system. CONSTITUTION:A switch circuit 38 is composed of FET transistor 39, resistor 40 and diode 41, and the output of a motor lock detection circuit 29 is connected to the cathode side of the diode 41. The anode side of it is connected to the gate of the transistor 39, and the resistor 40 is connected between the gate and a drain terminal. Also for lease, cathode/anode of the diodes 27, 28 are connected to one terminal of a capacitor 26. Therefore, when the large phase difference signal is generated, the output of the motor lock detection circuit 29 is turned to 'H', and diodes 27, 28 are connected between the terminals of capacitor of the 1st phase compensation circuit 15, the application of high voltage to the terminal of capacitor 26 is prevented. Therefore, the discharge time is shortened, and the pull-in response time is improved. |
