Apparatus responsive to the amount of refrigerant flow in a refrigerant flow in a refrigerant circulating system

摘要

An apparatus responsive to the amount of refrigerant flow in a refrigerant circulating system includes a sensing capacitor mounted in a refrigerant passage, the capacitance of the sensing capacitor being varied depending on a change in the dielectric constant of the refrigerant which in turn being dependent on the amount of the refrigerant. The sensing capacitor forms an element of a resistance-capacitance oscillatory circuit and it also forms a ring oscillator together with another capacitor and a plurality of inverters and resistors. The oscillation frequency of the ring oscillator is detected to determine the amount of the refrigerant flowing through the refrigerant passage.