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US 4,788,826 AGranted
Method and apparatus for preventing floodback in cooling apparatus
OwnerScott Higdoninventor
Life of this patent
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Abstract
A method and apparatus for preventing flood back in refrigeration systems which include a compressor, expansion valve and evaporator coil, by sensing the temperature differential across the evaporator coil and deactivating the compressor when the differential exceeds in the negative direction a predetermined amount of superheat. A second embodiment uses the sensing to operate flooded systems at peak efficiency at or near 0 superheat. A third embodiment uses all electronic circuitry to operate the system.
Claims1
An apparatus for detecting differential temperatures in a refrigeration system which includes at least one evaporator comprising:
- a power supply connectable to a source of electric current for providing appropriate voltages for all components;
- and,
- a first sensor connected to one side of the evaporator of the said refrigeration system;
- and,
- a second sensor connected to the other side of the evaporator of the said refrigeration system;
- and,
- a bridge circuit connected to said first sensor and said second sensor and said power supply for producing an electrical current when there is a temperature differential between said first sensor and saad second sensor;
- and,
- a differential amplifier connected to said bridge circuit and said power supply for increasing the current produced by said bridge circuit;
- and,
- further amplification means connected to said differential amplifier for furhter increasing the strength of said current produced by said differential amplifier;
- and,
- an output connected to said further amplification means including a light emitting device and a relay;
- and,
- a transistor connnected to saad power supply said further amplication means and said relay for activating said relay;
- and,
- additional further amplication means connected to said differential amplifier and said power supply for further increasing the magnitude of the output of said differential amplifier;
- and,
- zeroing means connected to said further amplification means for creating a baseline state;
- and,
- span adjustment means connected to said further amplification means for adjusting the span of the output of said further amplification means;
- and,
- signal forming means connected to said further amplification means to a condition readable by a microprocessor and computer.
20 more elements
Dependencies are inferred from the claim text.