摘要 |
<p>An apparatus for controlling liquid level, comprising containment means for containing and dispensing liquid, flow varying means operable for varying flow of liquid into the containment means, stepper motor means for operating the flow varying means, sensor means for sensing level of liquid in the containment means, and PDD controller means connected between the sensor means and the stepper motor means for controlling liquid level.</p> |
申请人 |
ALUMINUM COMPANY OF AMERICA, PITTSBURGH, PA., US |
发明人 |
KNAPP, DAVID JAMES, PITTSBURGH PENNSYLVANIA, US;WALTZ, MARION DWAIN, TARENTUM PENNSYLVANIA, US;CLARKE, DAVID WILLIAM, HEADINGTON OXFORD 0X3 7NP, GB |