Programmable time varying control system and method

• US 4,071,745 A
• Filed: 03/04/1977
• Issued: 01/31/1978
• Est. Priority Date: 03/04/1977
• Status: Expired due to Term

• Current Assignee: Burness C. Hall
• Original Assignee: B. C. Hall
• Inventors: Hall, B. C.
• Primary Examiner(s): Botz, Eugene G.
• Application Number:
  US05/774,393
• Time in Patent Office: 333 Days
• Field of Search: 236/46 R, 236/68 B, 165/22, 165/26, 165/11, 235/151, 340/172.5
• US Class Current: 700/16
• CPC Class Codes: G05B 19/075 for delivering a step function, a slope or a continuous function G05B19/06 takes precedence
• CPC Class Codes: G05D 23/1904 variable in time
• CPC Class Codes: G05D 23/20 with sensing elements having variation of electric or magnetic properties with change of temperature G05D23/13 takes precedence

Abstract

An electronic system and method are disclosed for controlling a measured temperature during a sequence of time intervals, in accordance with a sequence of selected reference temperatures, each corresponding to one of the intervals. The values of the reference temperatures are programmable and changeable by the user. The system and method can thus be used to establish thermostatic control in conformity with a referenced temperature that varies throughout the day, for example, hour by hour.

Claims

1. A system for controlling a measured temperature during a sequence of time intervals in accordance with a sequence of selected reference temperatures, each corresponding to one of the intervals, comprising:

means for storing a plurality of digital numbers, each representing a value of one of the reference temperatures;

means connectable to respond to a reference frequency source for repeatedly generating a digital number representative, at each generation, of the present time of day;

means for storing a digital number representative of a value of hysteresis;

updating means for repeatedly determining, from said time of day number, when one of said intervals embraces the present time and identifying the one of said reference temperatures corresponding to said embracing interval and for storing, as a current reference temperature value, a digital number representing the value of said identified reference temperature, said updating means including means for determining that as soon as said present time exceeds the last interval in said sequence, said time becomes embraced by the first interval in the sequence;

means connectable to be responsive to a sensor of said measured temperature for generating an electrical signal representation of said measured temperature;

comparison means responsive to said signal representation, to the current reference temperature number, and to the hysteresis number, for repeatedly generating control signals suitable for controlling thermal means affecting said measured temperature.

2. The system of claim 1, when there are twenty-four of said intervals, each interval having a duration of one hour.

3. The system of claim 1, further including means, accessible to a user, for entering the reference temperature numbers.

4. The system of claim 1, further including

means, accessible to a user, for selecting a time of day and for displaying the value of the reference temperature corresponding to the interval embracing the selected time and

means, accessible to a user, for entering a selected reference temperature value replacing the displayed value.

5. The system of claim 1,

further including means, accessible to a user, for entering a digital number representing a reference temperature adjustment and

wherein said comparison means includes means for performing said generating of control signals, with the current reference temperature value modified by the value of said adjustment number.

6. The system of claim 1, further including means for storing a digital number representative of an anticipator value;

and wherein said comparison means includes

means for generating said control signals capable of activating said thermal means, dependent on the relation of the measured temperature to the current reference temperature value as modified by the hysteresis value; and

means for generating said control signals, capable of deactivating said thermal means, dependent on the relation of the measured temperature to the current reference temperature value as modified by the anticipator value.

7. The system of claim 1, wherein said comparison means includes

means for generating a signal capable of initiating heating, when the measured temperature is less than the current reference temperature value minus the hysteresis value and

means for generating a signal capable of terminating heating, when the measured temperature becomes substantially equal to the current reference temperature value.

8. The system of claim 1, wherein said comparison means includes

means for generating a signal capable of initiating cooling, when the measured temperature is greater than the current reference temperature value plus the hysteresis value and

means for generating a signal capable of terminating cooling, when the measured temperature decreases to the current reference temperature value.

9. The system of claim 1, wherein said comparison means includes:

means for generating a signal capable of initiating heating, when the measured temperature is less than the current reference temperature value minus the hysteresis value and

means for generating a signal capable of terminating heating, when the measured temperature increases to the current reference temperature value;

means for generating a signal capable of initiating cooling, when the measured temperature is greater than the current reference temperature value plus the hysteresis value; and

means for generating a signal capable of terminating cooling, when the measured temperature decreases to the current reference temperature value.

10. The system of claim 1,

wherein said reference temperatures, including said current reference temperature, are relatively higher reference temperatures;

further including means, accessible to a user, for entering and storing a sequence of digital numbers, each representing a value of a relatively lower reference temperature and each corresponding to one of said intervals;

wherein said updating means further includes means for identifying the one of the lower reference temperatures corresponding to said embracing interval and for storing, as a current lower reference temperature value, a digital number representing the value of said identified lower reference temperature; and

wherein said comparison means includes

means for generating a signal capable of initiating heating, when the measured temperature is less than the current lower reference temperature value minus the hysteresis value and

means for generating a signal capable of terminating heating, when the measured temperature increases to the current lower reference temperature value,

means for generating a signal capable of initiating cooling, when the measured temperature is greater than the current higher reference temperature value plus the hysteresis value, and

means for generating a signal capable of terminating cooling, when the measured temperature decreases to the current higher reference temperature value.

11. The system of claim 1, further including

means for storing a digital number representative of a change to be produced in the measured temperature by said affecting means in response to said control signals;

and

means, responsive to the measured temperature signal representation and to the condition of said control signals and to said number representative of a change, for generating an alarm indication if said change is not actually produced in response to said control signals.

12. The system of claim 1,

further including means, accessible to a user, for entering a digital number representing a reference temperature adjustment;

means for repeatedly generating a digital number representative of the present value of an external temperature; and

wherein said comparison means includes means for performing, in response to said external temperature number, said generating of control signals with the current reference temperature value modified by the value of said adjustment number.

13. The system of claim 1,

wherein said control signals include an analog of a linear function of the measured temperature and the current reference temperature.

14. The system of claim 1,

including means for storing a digital number representative of the value of a parameter for multiple stage operation;

wherein the comparison means includes means for generating said control signals capable of commanding said thermal means to affect the measured temperature at a rate dependent on a comparison between said parameter value and the deviation of the measured temperature from the current reference temperature value.

15. A system for controlling a measured temperature during a sequence of time intervals in accordance with a sequence of selected reference temperatures, each corresponding to one of the intervals, comprising:

means, accessible to a user, for entering and storing a plurality of digital numbers, each representing a value of one of the reference temperatures;

means, accessible to a user, for entering and storing a digital number determining the duration of each of said intervals;

means connectable to respond to a reference frequency source for repeatedly generating a digital number representative, at each generation, of the present time of day;

means, accessible to a user, for entering and storing a digital number representative of a selected value of hysteresis;

updating means for repeatedly determining, from said time of day number, when one of said intervals embraces the present time and identifying the one of said reference temperatures corresponding to said embracing interval and for storing, as a current reference temperature value, a digital number representing the value of said identified reference temperature;

means connectable to be responsive to a sensor of said measured temperature for generating an electrical signal representation of said measured temperature;

comparison means, responsive to said signal representation, to the current reference temperature number, and to the hysteresis number, for repeatedly generating controlled signals suitable for thermal means affecting said measured temperature.

16. The system of claim 15,

wherein said reference temperatures, including said current reference temperature, are relatively higher temperatures;

and

further including means, accessible to a user, for entering and storing a sequence of digital numbers, each representing a value of a relatively lower reference temperature and each corresponding to one of said intervals; and

means, accessible to a user, for entering and storing a digital code indicative of a selected mode of operation; and

wherein said updating means further includes means for identifying the one of said lower reference temperatures corresponding to said embracing interval and for storing, as a current lower reference temperature value, a digital number representing the value of said identified lower reference temperature; and

wherein said comparison means further includes

means for generating, in response to a first value of said code, signals for controlling heating,

means for generating, in response to a second value of said code, signals for controlling cooling,

means for generating, in response to a third value of said code, signals for controlling heating in accordance with said current lower reference temperature value and cooling in accordance with said current higher reference temperature value, and

means for generating, in response to a fourth value of said code, signals for controlling both heating and cooling in accordance with the same one of said reference temperature values during all of said intervals.

17. The system of claim 15,

wherein said signal representation is an electrical analog signal;

and

said comparison means further includes means for coverting said signal to a sequence of digital representations.

18. A system for controlling a measured temperature in each of a plurality of zones, during a sequence of time intervals, comprising:

means for storing values, for each zone, of a sequence of reference temperatures, each corresponding to one of the time intervals;

means for selecting from the reference temperature values, for each zone, and during each interval, a current reference temperature value;

means for generating signals suitable for controlling means affecting the temperature of air delivered to the collection of zones, dependent on the relation of the measured temperatures, in the zones to the current reference temperatures of the zones; and

means for generating signals suitable for controlling means affecting the temperature of air delivered to each zone, dependent on the relation of measured temperature in the affected zone to the current reference temperature thereof.

19. A method for the control of a measured temperature during a sequence of time intervals in accordance with a sequence of selected reference temperatures, each corresponding to one of the intervals, comprising:

storing, in electronically readable form, a plurality of digital numbers, each representing a value of one of the reference temperatures;

repeatedly generating, in electronic form, a digital number representing the present time of day at each generation;

storing, in electronically readable form, a digital number representative of a value of hysteresis;

repeatedly determining, by an electronic comparison including the time of day number, when one of said intervals embraces the present time, including determining that as soon as said present time exceeds the last interval in said interval sequence, said time becomes embraced by the first interval in the sequence;

identifying the one of said reference temperatures corresponding to said embracing interval;

storing, in electronically readable form, as a current reference temperature value, a digital number representing the value of said identified reference temperature;

generating an electrical signal representation of said measured temperature;

electronically computing a digital number representing a function of the current reference temperature and the hysteresis number;

electronically comparing the function number and the representation of measured temperature; and

responsive to the results of the last mentioned comparing, generating signals suitable to control means affecting the measured temperature.