Control system for an air conditioner

• US 4,024,725 A
• Filed: 05/28/1975
• Issued: 05/24/1977
• Est. Priority Date: 05/29/1974
• Status: Expired due to Term

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Kamejima, Kohji, Kano, Minoru, Uzuhashi, Hideo, Uchida, Motokazu, Hosoda, Taisei
• Primary Examiner(s): Wayner, William E.
• Application Number:
  US05/581,710
• Time in Patent Office: 727 Days
• Field of Search: 236/68 B, 236/3, 236/91 E, 236/91 G, 236/91 R, 62/176 E, 62/209, 219/499, 219/497
• US Class Current: 62/176.6
• CPC Class Codes: G05D 23/1931 to control the temperature of one space

Abstract

A control system for an air conditioner having detectors for detecting at least the radiation temperature in a room or controlled space, a device for setting a desired room air parameter in response to the detected radiation temperature, and a controller for controlling the air conditioner in accordance with the desired room air parameter.

Claims

1. A system for controlling an air conditioner comprising first means for detecting the radiation temperature in a controlled space and providing an output indicative thereof, second means for setting a desired air parameter value in response at least to the output of said first means corresponding to the detected radiation temperature and providing an output indicative of the set air parameter, and a third means for controlling said air conditioner in accordance with the set air parameter from said second means, and further comprising fourth means for detecting the actual air parameter in the controlled space and providing an output indicative thereof, and fifth means for comparing the set air parameter from said second means with the actual air parameter from said fourth means and providing an output signal to the difference therebetween, said third means being responsive to the difference signal from said fifth means for controlling said air conditioner in accordance therewith.

2. A system according to claim 1 wherein air temperature is the air parameter set by said second means and detected by said fourth means.

3. A system according to claim 1, wherein the controlled space is a room.

4. A system according to claim 1, wherein said second means further includes bridge circuit means having said first means arranged therein, means for supplying voltage to said bridge circuit means, and means for differentially amplifying outputs of said bridge circuit means.

5. A system according to claim 1, further comprising sixth means for detecting the actual relative humidity in the controlled space and for providing an output indicative thereof, said second means being responsive to the output of said first means corresponding to the detected radiation temperature and to the output of said sixth means corresponding to the relative humidity for setting the desired air parameter in accordance therewith, said second means providing the set desired air parameter to said fifth means.

6. A system according to claim 5, wherein air temperature is the air parameter set by said second means.

7. A system according to claim 1, further comprising sixth means for setting a desired air flow velocity in response to the detected radiation temperature from said first means, and seventh means for controlling said air conditioner in accordance with the set air flow velocity from said sixth means.

8. A system according to claim 1, further including sixth means for detecting the actual relative humidity in the controlled space and providing an output indicative thereof, seventh means for setting a desired relative humidity in response to the output of said first means, eighth means for comparing the set relative humidity from said seventh means with the actual relative humidity from said sixth means and providing an output signal of the difference therebetween, and ninth means for controlling said air conditioner in accordance with the difference signal output from said eighth means.

9. A system according to claim 8, further comprising tenth means for setting a desired air flow velocity in response to the output of said first means, and eleventh means for controlling said air conditioner in accordance with the set air flow velocity from said tenth means.

10. A system according to claim 4, wherein said second means further includes means for limiting the lower value of the output of said amplifying means to a predetermined value.

15. A system according to claim 10, wherein said second means further includes means for limiting the upper value of the output of said amplifying means to a predetermined value.

11. A system for controlling an air conditioner comprising first means for detecting the radiation temperature in a controlled space and providing an output indicative thereof, second means for setting a desired air parameter value in response at least to the output of said first means corresponding to the detected radiation temperature and providing an output indicative of the set air parameter, and a third means for controlling said air conditioner in accordance with the set air parameter from said second means, and said first means including at least one thermistor for detecting the radiation temperature, and said second means including a power source having one terminal connected to one terminal of said thermistor, a first resistor connected to one terminal of said thermistor, a first resistor connected between the other terminal of said thermistor and the other terminal of said power source, a second resistor having one terminal coupled to the one terminal of said power source, a third resistor coupled between the other terminal of said second resistor and the other terminal of said power source, a differential amplifier having first and second input terminals connected respectively to a connection point between said thermistor and said first resistor and to a connection point between said second and third resistors, and a fourth resistor connected between the output terminal and the first input terminal of said differential amplifier.

12. A system according to claim 11, wherein said first resistor is a variable resistor.

13. A system according to claim 11, wherein said second means further includes a fifth resistor having one terminal coupled to the one terminal of said power source, a sixth resistor coupled between the other terminal of said fifth resistor and the other terminal of said power source, and a diode connected between the other terminal of said fifth resistor and the output terminal of said differential amplifier.

14. A system according to claim 13, wherein said first and sixth resistors are variable resistors.

16. A system according to claim 11, wherein air temperature is the air parameter set by said second means.