Abstract: A PWM control circuit includes a first PWM driver, a duty cycle compensator, and a second PWM driver. The first PWM driver receives duty cycle commands and generates a first PWM driver signal having a duty cycle that varies based on the duty cycle commands. The duty cycle compensator receives the first PWM driver signal and a sensor signal representative of a value of a sensed physical parameter. The duty cycle compensator supplies compensated duty cycle commands based on the duty cycle of the first PWM driver signal and the value of the sensed physical parameter. The second PWM driver receives the compensated duty cycle commands and generates a hybrid PWM driver signal having a duty cycle that varies based on the compensated duty cycle commands. The resulting hybrid signal provides improved resolution for control that cannot be provided by a single PWM driver alone.

Abstract: A valve assembly includes mechanical hard stops that are integral with the actuator assembly. The valve assembly includes a valve body, a valve element, and an actuator assembly. The valve element is disposed within the valve body and is moveable between an open position and a closed position. The actuator assembly is coupled to the valve element and is adapted to receive one or more position control signals, and is operable to selectively move the valve element between the open and closed positions. An engagement structure is coupled to the valve element and is moveable therewith. A stop structure is fixedly coupled to the actuator assembly and is configured to engage the engagement structure when the valve is at least in one of the open and closed positions.

Abstract: A valve assembly includes a fully-integrated actuator assembly. The actuator assembly includes, within a single housing assembly, a torque source, a position sensor, a gear train, and an output shaft. The torque source is adapted to receive one or more position control signals and, in response, to supplies a drive force. The position sensor is coupled to receive the drive force and, in response, supplies a signal representative of valve position. The output shaft is coupled to receive the drive force from the torque source, and thereby selectively moves the valve, upon receipt of the drive force, between the open and closed positions.

Abstract: A plug valve assembly includes a plug and a segment seal assembly. The segment seal assembly is configured to reduce the differential pressure load across the segment seal assembly when the valve is closed. The segment seal includes an opening in fluid communication with a sealed vent region that is formed between the segment seal and the plug.