Patent ID: 9509243
Filing Date: 2016-11-29
CPC Classification: F16K,H02P

Claim Text:
1. A self-calibrating linear actuator configured to control a spring return valve with variable stroke, wherein the actuator comprises: a motor; a spindle coupled to an output of the motor; a motor controller coupled to the motor; a microcontroller coupled to the motor controller; a back electromotive force (BEMF) circuit, coupled to the motor, configured to provide to the microcontroller a BEMF value for each motor step, wherein the microcontroller is configured to cause the actuator to: wherein the microcontroller is configured to subtract the second predetermined number of motor steps and the second number of motor steps from the first number of motor steps, and store the difference of number of motor steps, wherein the difference of number of motor steps is calibrated touch point for the actuator.