Modulated temperature control for environmental chamber
AssigneeLab-Line Instruments, Inc.
InventorsJohn A. Benevelli, Michael L. Murray, Duane C. Drinkwine
Life of this patent
Estimating the term…
Loading patent…
AssigneeLab-Line Instruments, Inc.
InventorsJohn A. Benevelli, Michael L. Murray, Duane C. Drinkwine
Estimating the term…
A temperature-controlled environmental chamber includes a resistance heater controlled by a solid state relay and a refrigeration unit including an electronically controlled suction throttling valve connected in the refrigerant line between the evaporator and the inlet of the compressor. A temperature controller senses the temperature in the chamber and compares it to a set point temperature and outputs a pulse-width modulated control signal indicative of the difference between the two temperatures. The control signal directly controls the heater relay for substantially continuous variation between minimum and maximum heating conditions. The control signal is converted to an analog signal for controlling the throttling valve of the refrigeration unit for substantially continuous variation between maximum and minimum cooling conditions, so that the amount of cooling provided is inversely proportional to the amount of heating provided. A hot gas bypass is provided for maintaining a minimum input pressure on the condenser and a refrigerant bypass is provided to maintain the input temperature of the compressor below a predetermined maximum.
Apparatus for controlling the air temperature of a served space which is equipped with a heat source and a cold source, said apparatus comprising:
Apparatus for controlling the air temperature of a served space which is equipped with a heat source and a cold source, said apparatus comprising:
A method for controlling the air temperature of a served space which is equipped with a heat source and a cold source, said method comprising the steps of:
Dependencies are inferred from the claim text.