I/P converter with simulated compensation
AssigneeRosemount Inc.
InventorBruce D. Rovner
Life of this patent
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Abstract
A current-to-pressure converter sets line pressure to a desired pressure indicated by the current. A circuit senses the line pressure and the current, receives compensation, and outputs a compensated difference between line and desired pressures. A first driver circuit provides actuator drive based on the compensated output. The actuator controls the line pressure, but presents a temperature sensitive, reactive load to the actuator drive. A simulated load simulates a resistive part of the actuator load. A second driver provides simulated drive to the simulated load. The second driver generates the compensation which simulates actuator drive parameters, but is isolated from reactive effects and temperature sensitivity of the actuator.
Claims15
A converter controlling a line pressure according to a signal received by the converter indicating a desired pressure, comprising:
- sensing means for sensing the line pressure and the signal, the sensing means receiving compensation and providing a compensated output representative of the line and desired pressures;
- first driver means for providing an actuator drive as a function of the compensated output;
- actuator means for controlling the line pressure as a function of the actuator drive, the actuator means presenting an actuator load to the actuator drive;
- a simulation circuit including a simulated load simulating a desired portion of the actuator load and a second driver providing drive thereto as a function of the compensated output and generating the compensation representative of the actuator drive but isolated from the actuator load.
A converter controlling a line pressure according to a signal received by the converter indicating a desired pressure, comprising:
- sensing means for sensing the line pressure and the signal, the sensing means receiving compensation and providing a compensated output representative of the line and desired pressures;
- first driver means for providing an actuator drive as a function of the compensated output;
- an actuator controlling the line pressure as a function of the actuator drive, the actuator presenting an actuator load to the actuator drive;
- a simulated load simulating a desired portion of the actuator load;
- and
- second driver means for providing a simulated drive to the simulated load as a function of the compensated output, the second driver means further generating the compensation as a function of the simulated drive such that the compensation is representative of the actuator drive but isolated from the actuator load.
Dependencies are inferred from the claim text.