| 摘要 |
<p>PURPOSE:To control the opening of an electric valve precisely by controlling the phase of the driving power source of the electric valve outputted from a thyristor module at a gate-pulse generator. CONSTITUTION:A valve opening command signal (a) is inputted into a subtraction unit 5, in which a deviation is calculated from a valve opening feedback (b) detected by a position detector 3 fixed on a valve spindle 2 of an electric valve 1 for detecting the opening position and signal-converted by a converter 4. This deviation signal is inputted into a decision unit 6, and sent to a gate-pulse generator 7. The generator 7 receives the input of the phase of an input power source (d) to a thyristor module from a phase detector 10, and generates a gate pulse (c) at a proper timing of input voltage on the basis of the value of the deviation inputted from the decision unit 6.</p> |
