초록 ▼

Presented is a control device which may be added to an already existing air conditioning refrigeration system, or which may be built into the air conditioning refrigeration system at the factory and which monitors the temperature and pressure of a refrigerant flowing in the refrigeration system to d

Presented is a control device which may be added to an already existing air conditioning refrigeration system, or which may be built into the air conditioning refrigeration system at the factory and which monitors the temperature and pressure of a refrigerant flowing in the refrigeration system to determine increases or decreases in the ratio of pressure change to temperature change above or below a predetermined and desirable super-heat temperature for the particular system involved. The increase or decrease of this super-heat beyond predetermined upper and lower limits sustained for a predetermined interval, initiates deactivation of the refrigeration system so as to prevent damage thereto.

대표청구항 ▼

Apparatus for quantitatively monitoring the amount of super-heat contained in the refrigerant vapor of an air conditioning refrigeration system and locking-out the refrigeration system in response to sustained variation for longer than a selected interval of the super-heat above or below predetermin

Apparatus for quantitatively monitoring the amount of super-heat contained in the refrigerant vapor of an air conditioning refrigeration system and locking-out the refrigeration system in response to sustained variation for longer than a selected interval of the super-heat above or below predetermined quantitative limits defining a “deadband”comprising: (a) means for independently sensing the temperature and pressure of the refrigerant vapor and reflecting the sensed values of the temperature and pressure as values of electrical resistance; (b) a power supply adapted to provide a predetermined regulated output; (c) a bridge circuit connected to said power supply and to said temperature and pressure sensors and responsive to said values of electrical resistance and calibrated to balance said values of electrical resistance to produce a predetermined electrical output signal correlated quantitatively to said super-heat; (d) a preamplifier connected to receive said predetermined electrical output signal from said bridge circuit; (e) a preamplifier bias circuit connected to receive the output from said preamplifier, said preamplifier bias circuit being calibrated to produce a zero voltage output from said preamplifier when said bridge circuit produces said predetermined electrical output signal; (f) an integrator circuit connected to receive the output signal of the preamplifier bias circuit and adapted to produce either a positive or negative output when said super-heat varies from said predetermined value; (g) a pair of comparator circuits connected to receive the output from said integrator circuit and adapted to produce an output signal through one or the other of two output circuits depending upon whether the output from said integrator is positive or negative and of a predetermined value; and (h) lock-out means responsive to variations in said bridge circuit output above or below said predetermined quantitative limits whereby lock-out timing becomes a function of the amount that said predetermined quantitative limits of super-heat are exceeded.