| 摘要 |
PURPOSE:To improve the responsiveness and the control accuracy for various types of control systems using the hydraulic pressure, by using directly electricity to perform the control driving. CONSTITUTION:The liquid level in a controlled system tank 1 is detected by a level detector 2 and then fed to a controller 3 in the form of a level signal SL. Then a deviation is calculated between the signal SL and a controller setting signal SS obtained by setting previously the liquid level. Thus a control signal SC which shows a proper opening of a control valve 7 is calculated. The signal SC is fed to an electric positioner 34 using a thyristor, and a deviation is calculated between the signal SC and a feedback signal SF of a gear mechanism 32 of an electric driving part. Based on this deviation, an AC power supply AC is controlled by the gate ignition control of the thyristor. That is, the power supply AC is converted into an AC signal SAC of a specific waveform and supplied to a motor 30 through the positioner 34. |
