Abstract: A system for measuring current in an H-Bridge motor drive circuit and using that current to determine the output of a device powered by the motor. A particular embodiment is disclosed for a motor-driven fluid pump. Motor current is measured at predetermined pump pressures and flow rates to create calibration tables relating motor current to pump pressure. Once calibrated, the system determines pump pressure based on motor current by referring to the calibration tables. In an embodiment, the pump is driven to achieve a predetermined fluid dispense profile. The system monitors pump pressure by measuring motor current and determines if the dispense profile is being achieved and sets alarms if predetermined thresholds are not maintained. The system also detects pump wear based on the current measurements and issues warnings to the user in such conditions.

Abstract: A system for measuring current in an H-Bridge motor drive circuit and using that current to determine the output of a device powered by the motor. A particular embodiment is disclosed for a motor-driven fluid pump. Motor current is measured at predetermined pump pressures and flow rates to create calibration tables relating motor current to pump pressure. Once calibrated, the system determines pump pressure based on motor current by referring to the calibration tables. In an embodiment, the pump is driven to achieve a predetermined fluid dispense profile. The system monitors pump pressure by measuring motor current and determines if the dispense profile is being achieved and sets alarms if predetermined thresholds are not maintained. The system also detects pump wear based on the current measurements and issues warnings to the user in such conditions.