The present invention provides a system to regulate fluid flow having a light switch that controls a light, wherein the light switch is in electrical communication with a wireless transmitter; and at least one valve interposed on at least one fluid supply line wherein said at least one valve is normally closed, cutting off the flow of fluid in the at least one fluid supply line, wherein the at least one valve is in electrical communication with a wireless receiver such that when the light switch is activated the wireless transmitter signals the wireless receiver to open the valve, allowing flow of fluid in the fluid supply line. The present invention also provides another system using a photocell switch to actuate the valve.

A valve control device includes a housing provided with a control shaft, a motor for driving the control shaft to rotate, a control circuit board connected to the motor, and a sensor for detecting a rotational position of the control shaft. The sensor is connected to the control circuit board, which controls the motor to drive the control shaft to rotate in response to a position signal returned by the sensor. The valve control device may further include a position pointer, an indicating light, or a buzzer to facilitate observation of the opening and closing position of the valve.

A flow control device for use in a heat exchange system, including: a housing, a movable valve member and a drive control member, the housing being formed to have a mounting cavity, a first interface and a second interface, while the drive control member includes a control unit, a power output unit, a magnetic element and a detection element; the power output unit provides power to the movable valve member, while the detection element and the control unit are electrically connected, and the magnetic element and the power output unit are mutually assembled and oppositely fixed, the power output unit may drive the magnetic element to rotate; the detection element and the magnetic element are oppositely disposed, the detection element being located within the range of the magnetic field of the magnetic element, the detection element may sense a magnetic pole change of the magnetic element.

A valve without position indicating switches. Positions of the valve are detected from current magnitude measurements and current profile analytics. The current profile may be learned initially and relearned and adapted at each operation. The valve may be opened and closed by a driver that is actuated by an electrical current to control the opening and closing of the valve. The current may be regulated by a controller to open and close the valve appropriately.

An air turbine start system includes an air supply duct, an air turbine starter, a starter air valve, a stepper motor, and a controller. The air turbine starter is coupled to the air supply duct to selectively receive a flow of pressurized air therefrom. The starter air valve is mounted on the air supply duct and is movable between a closed position and a plurality of open positions. The stepper motor is coupled to the starter air valve and is configured, in response to valve position commands, to move the starter air valve between the closed position and one or more of the plurality of open positions. The controller is coupled to the stepper motor and is configured to supply the valve position commands to the stepper motor and determine a position of the starter air valve based on the valve position commands supplied to the stepper motor.

A control system for regulating fluid flow and pressure downstream a waterworks main valve includes a variable orifice device disposed upstream a pressure reducing pilot. The variable orifice device is in fluid communication with the pressure reducing pilot and a cover chamber of the main valve. Opening and closing the variable orifice device causes the main valve to modulate and the pressure of fluid downstream the main valve to be changed while avoiding pressure oscillations during the transition between pressure setpoints.

A force actuator including an actuator housing, in which, via transmission elements, an electric motor is arranged to drive a displaceable roller screw along the longitudinal axis of the force actuator, and in which a rotatable roller cage which is in engagement with the transmission elements is provided with at least one threaded roller, the threaded roller being in threaded engagement with the roller screw, and the roller screw being prevented from rotating around the longitudinal axis.

A method for operating a control valve using an HVAC actuator is described, the method comprises a circuit of the HVAC actuator executing the steps of: monitoring (S1) a rotation angle (ϕ) associated with a drive torque (M.sub.drive) applied by the HVAC actuator for moving the valve member; detecting (S2) a blocking of the control valve, if the applied drive torque (M.sub.drive) effects a change of the rotation angle (Δϕ) which is smaller than a threshold angle (ϕ.sub.th); upon detection of the blocking, controlling the HVAC actuator to repeatedly change the applied drive torque (M.sub.drive) between a first torque value (M1) and a second torque value (M2); and controlling the HVAC actuator to periodically modulate (S4) the first torque value (M1) between a third torque value and a fourth torque.

One implementation is a device for determining the position of a valve. The device uses a current profile including at least the magnitude of current, and an analysis module for using the current profile and the state of the valve to perform at least one action.

An electric linear drive for a gear rack including a stepping motor, a holding plate, a motor output gear, and a gearing. The holding plate, the stepping motor, the motor output gear, and the gearing form a drive unit that, together with a basic housing, form an overall housing. The overall housing has an opening for the insertion of the gear rack. Drive electronics are fixed to the holding plate such that electrical connections are present on the outside of the overall housing. The stepping motor has a rotor axis arranged parallel to the holding plate. During assembly, a rack belonging to a device to be driven can be pushed into a lateral opening of the overall housing, and the device to be driven can be connected to the overall housing. The electric linear drive is compact, allowing devices to be driven to be located close to one another.