Thermostat

• US 5,396,048 A
• Filed: 04/23/1992
• Issued: 03/07/1995
• Est. Priority Date: 04/23/1992
• Status: Expired due to Fees

• Current Assignee: Cadet Manufacturing Co. (Glen Dimplex Europe Holdings Ltd.)
• Original Assignee: Cadet Manufacturing Co. (Glen Dimplex Europe Holdings Ltd.)
• Inventors: King, Frederick J., Rochat, William V., Mosher, Vance C.
• Primary Examiner(s): Paschall, Mark H.
• Application Number:
  US07/872,698
• Time in Patent Office: 1,048 Days
• Field of Search: 219/492, 219/493, 219/481, 219/482, 219/494, 219/507, 219/508, 219/511, 219/501, 307/117
• US Class Current: 219/494
• CPC Class Codes: G05D 23/1904 variable in time
• CPC Class Codes: G05D 23/24 the sensing element having a resistance varying with temperature, e.g. a thermistor

Abstract

A thermostat for cyclically regulating actual ambient temperature, Ta, to either of two values, T1 and T2, for selectable durations. A switch allows T1 to be selected and deselected and a sensor detects Ta, while a controller is connected to the switch and the sensor. The controller is capable of defining T1 and T2 values. The controller further has a memory to store a cycle period duration, a detector to detect when the switch selects or deselects T1, and a timer which establishes T1 duration based on the time between T1 selection and deselection, and establishes T2 duration as at least a portion of the remainder of the cycle period. The controller automatically cyclically repeats the established T1 and T2 durations during each cycle period until T1 is again selected by the switch. A signal generator in the controller generates a control signal corresponding to the difference between Ta and T1 or T2 during their respective durations. A power interface for a thermostat supplies power for thermostat components by a power control switch and a power storage circuit.

Claims

1. A thermostat which generates a control signal for cyclically regulating actual ambient temperature Ta, to either of two values, T1 and T2, for selectable durations, comprising:

(a) a switch for selecting and deselecting T1;

(b) a sensor for detecting Ta;

(c) a controller connected to said switch and said sensor, said controller having;

a means for defining T1 and T2 values;

a memory to store a cycle period duration;

a detector to detect when the switch selects or deselects T1;

a timer which establishes T1 duration based on the time between T1 selection and deselection, and establishes T2 duration as an least a portion of the remainder of the cycle period, and automatically cyclically repeats the established T1 and T2 durations during each cycle period until T1 is again selected by the switch;

a signal generator which generates a control signal corresponding to the difference between Ta and T1 or T2 during their respective durations.

2. A thermostat as defined in claim 1 wherein the means for defining T1 and T2 values comprises a T1 selector which allows T1 to be varied by a user.

3. A thermostat as defined in claim 2 wherein the cycle period duration stored by said controller is 24 hours.

4. A thermostat as defined in claim 3 wherein said timer establishes T1 duration as the time between T1 selection and deselection plus an initial period of no more than 1 hour.

5. A thermostat as defined in claim 3 wherein said timer establishes T1 duration as the time between T1 selection and deselection plus an initial period of about 15 minutes.

7. A thermostat as defined in claim 3 wherein said timer establishes T2 duration as the cycle period minus T1 duration.

8. A thermostat as defined in claim 2 wherein the switch for selecting and deselecting T1 is a pushbutton switch.

9. A thermostat as defined in claim 7 wherein the cycle period duration stored by said controller is 24 hours.

10. A thermostat as defined in claim 9 wherein T1 duration is established as the time between T1 selection and deselection plus an initial period of no more than 1 hour.

11. A thermostat as defined in claim 10 wherein the means for defining T1 and T2 values defines T2 as T1 minus a numerical value.

12. A thermostat as defined in claim 11 wherein said timer establishes T2 duration as the cycle period minus T1 duration.

6. A thermostat as defined in claim wherein the means for defining T1 and T2 values defines T2 as T1 minus a numerical value.

13. A thermostat for cyclically controlling an electric heater to regulate actual ambient temperature, Ta, to either of two values, T1 and T2, for selectable durations, comprising:

(a) a switch for selecting and deselecting T1;

(b) a sensor for detecting Ta;

(c) a controller connected to said switch and said sensor, said controller having;

a selector which allows T1 to be defined by a user;

a means for defining T2 value;

a memory to store a cycle period duration;

a detector to detect when the switch selects or deselects T1;

a timer which establishes T1 duration based on the time between T1 selection and deselection, and establishes T2 duration as at least a portion of the remainder of the cycle period, and automatically cyclically repeats the established T1 and T2 durations during each cycle period until T1 is again selected by the switch;

a signal generator which generates a control signal corresponding to the difference between Ta and T1 or T2 during their respective durations;

(d) a power interface for connection to the heater which provides heater current of a value or duration corresponding to the control signal.

14. An electric heating system comprising an electric heater and a thermostat connected to said heater to regulate actual ambient temperature, Ta, to either of two values, T1 and T2, for selectable durations, said thermostat comprising:

(a) a switch for selecting and deselecting T1;

(b) a sensor for detecting Ta;

(c) a controller connected to said switch and said sensor, said controller having;

a selector which allows T1 to be defined by a user;

a means for defining T2 value;

a memory to store a cycle period duration which is 24 hours;

a detector to detect when the switch selects or deselects T1;

a timer which establishes T1 duration based on the time between T1 selection and deselection, and establishes T2 duration as at least a portion of the remainder of the cycle period, and automatically cyclically repeats the established T1 and T2 durations during each cycle period until T1 is again selected by the switch;

a signal generator which generates a control signal corresponding to the difference between Ta and T1 or T2 during their respective durations;

(d) a power interface connected to the heater which provides heater current of a value or duration corresponding to the control signal.

15. An electric heating system as defined in claim 14 wherein the means for defining T1 and T2 values defines T2 as T1 minus a numerical value, and wherein said timer establishes T1 duration as the time between T1 selection and deselection plus an initial period.

16. An electric heating system as defined in claim 14 wherein said timer establishes T2 duration as the cycle period minus T1 duration.

17. An electric heating system as defined in claim 14 wherein the switch for selecting and deselecting T1 is a pushbutton switch.

18. A thermostat for controlling an electrical load, said thermostat having a power interface comprising:

(a) a power control switch connectable between a first side of the load and a first side of a power source for the load, and which controls power therethrough in response to a signal; and

(b) a power storage circuit to provide power for thermostat components and which is connected across the switch so as to be charged when the power control switch is off.

19. A thermostat as defined in claim 18, wherein said power storage circuit comprises a capacitor and associated charging circuit.

20. A thermostat as defined in claim 19 wherein the capacitor charging circuit includes a rectifier and the capacitor is connected across the power control switch through the rectifier.

21. A thermostat as defined in claim 19 wherein the capacitor charging circuit additionally includes a voltage reduction circuit to reduce the maximum voltage to which the capacitor can be charged below that of the power source, and wherein the power interface additionally comprises a voltage regulator connected to regulate voltage between the power storage circuit and thermostat components.

23. A thermostat as defined in claim 21, wherein said power storage circuit comprises a capacitor and associated charging circuit.

25. A thermostat as defined in claim 23 wherein the capacitor charging circuit additionally includes a voltage reduction circuit to reduce the maximum voltage to which the capacitor can be charged below that of the power source, and wherein the power interface additionally comprises a voltage regulator connected to regulate voltage between the power storage circuit and thermostat components.

22. A thermostat for controlling an electrical load to regulate ambient temperature to a desired value, said thermostat comprising:

(a) a sensor for detecting ambient temperature;

(b) a controller connected to said switch and said sensor, said controller having a signal generator which generates a control signal corresponding to the difference between the ambient and desired temperature;

(c) a power interface for use with a power control switch which can control power therethrough in response to the control signal, the power interface having a power storage circuit to provide power for thermostat components and which is connectable across the switch so as to be charged when the power control switch is off.

24. A thermostat as defined in claim 22 wherein the capacitor charging circuit includes a rectifier and the capacitor is connectable across the power control switch through the rectifier.

26. A thermostat for cyclically regulating actual ambient temperature, Ta, to either of two values, T1 and T2, for selectable durations, comprising:

(a) a switch for selecting and deselecting T1;

(b) a sensor for detecting Ta;

(c) a controller connected to said switch and said sensor, said controller having;

a means for defining T1 and T2 values which includes a T1 selector which allows T1 to be varied by a user

a memory to store a cycle period duration;

a detector to detect when the switch selects or deselects T1;

a timer which establishes T1 duration based on the time between T1 selection and deselection, and establishes T2 duration as at least a portion of the remainder of the cycle period, and automatically cyclically repeats the established T1 and T2 durations during each cycle period until T1 is again selected by the switch;

a signal generator which generates a control signal corresponding to the difference between Ta and T1 or T2 during their respective durations; and

(d) a power interface comprising;

a power control switch connectable between a first side of the load and a first side of a power source for the load, and which controls power therethrough in response to the control signal;

a power storage circuit to provide power for thermostat components and which is connected across the switch so as to be charged when the power control switch is off, said power storage circuit comprising a capacitor and associated charging circuit.

27. A thermostat as defined in claim 26 wherein the cycle period duration stored by said controller is 24 hours.

28. A thermostat as defined in claim 27 wherein the means for defining T1 and T2 values defines T2 as T1 minus a numerical value, and wherein said timer establishes T1 duration as the time between T1 selection and deselection plus an initial fixed period.

29. A thermostat as defined in claim 27 wherein said timer establishes T2 duration as the cycle period minus T1 duration.

30. A thermostat as defined in claim 27 wherein the switch of selecting and deselecting T1 is a pushbutton switch.

31. A heating system including an electric heater one side of which is connected to a first side of a power source, and including a thermostat for cyclically regulating actual ambient temperature, Ta, to either of two values, T1 and T2, for selectable durations, the thermostat comprising:

(a) a switch for selecting and deselecting T1;

(b) a sensor for detecting Ta;

(c) a controller connected to said switch and said sensor, said controller having;

a means for defining T1 and T2 values which includes a T1 selector which allows T1 to be varied by a user

a memory to store a cycle period duration;

a detector to detect when the switch selects or deselects T1;

a timer which establishes T1 duration based on the time between T1 selection and deselection, and establishes T2 duration as at least a portion of the remainder of the cycle period, and automatically cyclically repeats the established T1 and T2 durations during each cycle period until T1 is again selected by the switch;

a signal generator which generates a control signal corresponding to the difference between Ta and T1 or T2 during their respective durations; and

(d) a power interface comprising;

a power control switch connected between a second side of the power source and the heater and which controls power therethrough to the heater in response to the control signal;

a power storage circuit to provide power for thermostat components and which is connected across the switch so as to be charged when the power control switch is off, said power storage circuit comprising a capacitor and associated charging circuit,