| 摘要 |
PURPOSE:To suppress effectively the pulsation occurring to a controlled system, by rectifying the alternating carrier signal component among the frequency components of a feedback signal. CONSTITUTION:An amplifying/modulating circuit 1 gives the modulation of pulse width to a deviation signal Sepsilon with a rectangular wave Sm, i.e. a carrier signal. A subtractor circuit 4 is provided between the circuit 1 and a driving circuit 3 of an electromagnetic direction switching valve 2. The circuit 4 subtracts the rectifying output Sd of the signal Sf corresponding to the pulsation given from a position detector 6 of a hydraulic cylinder 5 from the waveheight value of the input signal Sp. As a result, the valve 2 is driven without its spool reaching the stroke end. |
