An improved rotary spool control system for a closed hydrostatic circuit and method to use the same. The control spool utilizes metering of the spool notches and specifically the metering of the servo drain notch wherein the drain notch is of irregular cross sectional shape. Because of the metering and irregular cross sectional shape, this spool is able to provide an aggressive response while still having smooth linear control. The method of creating the feedback control includes displacing pressurized fluid through the hydrostatic circuit rotating the control spool to create an error signal removing the error signal with a control sleeve and metering the servo piston drain with the irregularly shaped metering porting notch.

 
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< Valve arrangement in a hydraulic circuit, use of the same and arrangement for controlling a hydraulic vehicle drive

< Hydraulic spool valve for use in a hydraulic vehicle drive

> Motor controller incorporating an electronic circuit for protection against inrush currents

> Bent axis hydrostatic module with multiple yokes

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