Patent ID: 7934518
Filing Date: 2011-05-03
Classification: F16K,Y10T

Abstract:
1. A device for sensing an opening degree of a valve installed inside a fluid transfer pipe to control a flow rate of a fluid, the device comprising: a case defining an inner space; a shaft extending through the case to be exposed in the space, the shaft transmitting a movement of the valve by means of rotation; a main gear installed inside the case and coupled around the shaft; a potentiometer comprising a meter gear installed to engage with the main gear and rotate and a meter for converting rotation of the meter gear into an electric signal; and a control circuit board comprising an operation unit for receiving an input of a command, a control circuit, and a band gap setting means, wherein the control circuit receives the electric signal from the potentiometer and sets limit values based on the input and the electric signal from the potentiometer, the limit values comprising upper and lower limit values, the upper limit value corresponding to a position of the valve in a fully open condition and to a maximum flow rate of the fluid, the lower limit value corresponding to a position of the valve in a closed condition and to a minimum or zero flow rate of the fluid, the control circuit converts the electric signal between the upper and lower limit values at a predetermined proportion to calculate a degree of opening, and the band gap setting means enables the control circuit to recognize an angle or a position near the limit values as one of the fully open and closed conditions.