Temperature control device with automatically adjustable backlighting

• US 10,416,749 B2
• Filed: 11/07/2018
• Issued: 09/17/2019
• Est. Priority Date: 05/26/2015
• Status: Active Grant

• Current Assignee: Lutron Technology Company LLC
• Original Assignee: Lutron Technology Company LLC
• Inventors: Killo, Jason C., Mosebrook, Donald R., Steiner, James P.
• Primary Examiner(s): Sherman, Stephen G
• Application Number:
  US16/183,674
• Publication Number:
  US 20190073019A1
• Time in Patent Office: 314 Days
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/46 Improving electric energy efficiency or saving
• CPC Class Codes: F24F 11/52 Indication arrangements, e.g. displays
• CPC Class Codes: F24F 11/523 for displaying temperature data
• CPC Class Codes: F24F 11/56 Remote control
• CPC Class Codes: F24F 11/61 using timers
• CPC Class Codes: F24F 11/66 Sleep mode
• CPC Class Codes: F24F 2110/10 Temperature
• CPC Class Codes: F24F 2120/00 Control inputs relating to users or occupants
• CPC Class Codes: G05B 2219/2614 HVAC, heating, ventillation, climate control
• CPC Class Codes: G05D 23/1902 characterised by the use of a variable reference value
• CPC Class Codes: G06F 1/3234 Power saving characterised by the action undertaken
• CPC Class Codes: G06F 3/04847 Interaction techniques to control parameter settings, e.g. interaction with sliders or dials
• CPC Class Codes: G09G 2320/0626 for control of overall brightness
• CPC Class Codes: G09G 3/2003 Display of colours specific for liquid crystal displays G09G3/3607

Abstract

A temperature control device (e.g., a thermostat) may be configured to control an internal heat-generating electrical load so as to accurately measure a present temperature in a space around the temperature control device. The temperature control device may comprise a temperature sensing circuit configured to generate a temperature control signal indicating the present temperature in the space, and a control circuit configured to receive the temperature control signal and to control the internal electrical load. The control circuit may be configured to energize the internal electrical load in an awake state and to cause the internal electrical load to consume less power in an idle state. The control circuit may be configured to control the internal electrical load to a first energy level (e.g., a first intensity) during the awake state and to a second energy level (e.g., second intensity) that is less than the first during the idle state.

Claims

1. A method for controlling an HVAC system by a control circuit of a temperature control device, the method comprising:

receiving a temperature control signal indicating a temperature in a space around the temperature control device;

receiving a set point temperature;

controlling, in an idle state, an internal electrical load to a first state;

sampling, in the idle state, the temperature control signal;

determining, in the idle state, a sampled temperature based on the temperature control signal;

storing, in the idle state, the sampled temperature in memory;

controlling, in an awake state, the internal electrical load to a second state, wherein the internal electrical load consumes more power in the second state than in the first state;

ceasing sampling of the temperature control signal, in the awake state;

retrieving, in the awake state, the sampled temperature stored in the memory during the idle state;

comparing the retrieved sampled temperature to the set point temperature; and

based on comparing the retrieved sampled temperature to the set point temperature, controlling the HVAC system.

2. The method of claim 1, further comprising:

entering the awake state in response to an actuation of a button.

3. The method of claim 2, wherein controlling the internal electrical load comprises controlling a button backlight circuit configured to illuminate the button with a first duty cycle during the awake state and with a second duty cycle during the idle state, the second duty cycle having a decreased on time percentage compared to the first duty cycle, the decreased on time percentage of the second duty cycle being greater than zero percent.

4. The method of claim 3, further comprising:

controlling the button backlight circuit in response to an ambient light level around the temperature control device measured by a light detector circuit.

5. The method of claim 4, further comprising adjusting the second duty cycle of the button backlight circuit during the idle state in response to the ambient light level.

6. The method of claim 4, further comprising turning off the button backlight circuit when the ambient light level exceeds an ambient light threshold during the idle state.

7. The method of claim 3, further comprising waiting for a period of time after the actuation of the button before returning to the idle state.

8. The method of claim 7, wherein the period of time is a predetermined value stored in the memory.

9. The method of claim 7, wherein the period of time is a function of the first duty cycle during the awake state.

10. The method of claim 1, further comprising displaying a present temperature on a visual display.

11. The method of claim 1, wherein the internal electrical load comprises a visual display for displaying information for a user, further wherein controlling the internal electrical load to the first state comprises turning the visual display off during the idle state;

and wherein controlling the internal electrical load to the second state comprises turning the visual display on during the awake state.

12. The method of claim 1, wherein the internal electrical load comprises a display backlight circuit for a visual display, further wherein controlling the internal electrical load to the first state comprises turning the display backlight circuit off during the idle state;

and wherein controlling the internal electrical load to the second state comprises turning the display backlight circuit on during the awake state.

13. A method comprising:

sampling a temperature signal, the temperature signal indicating a temperature in a space around a temperature control device;

determining, in an idle state, a sampled temperature based on the temperature signal;

storing, in the idle state, the sampled temperature in memory;

controlling, in the idle state, an internal electrical load to a first state; and

controlling, in an awake state, the internal electrical load to a second state, wherein the internal electrical load consumes more power in the second state than in the first state;

ceasing sampling of the temperature signal, in the awake state;

retrieving, in the awake state, the sampled temperature stored in the memory during the idle state;

comparing the retrieved sampled temperature to a set point temperature; and

based on comparing the retrieved sampled temperature to the set point temperature, controlling an HVAC system.

14. The method of claim 13, further comprising transitioning from the idle state to the awake state in response to an actuation of a button;

and

waiting for a period of time after the actuation of the button before returning to the idle state, the period of time being a predetermined value stored in the memory or a function of an intensity during the awake state.

15. The method of claim 13, further comprising:

measuring, via a light detector circuit, an ambient light level; and

controlling a button backlight circuit in response to the measured ambient light level.

16. The method of claim 15, further comprising adjusting an intensity of the button backlight circuit during the idle state in response to the measured ambient light level.

17. A method comprising:

sampling a temperature signal, the temperature signal indicating a temperature in a space around a temperature control device;

determining, in an idle state, a sampled temperature based on the temperature signal;

storing, in the idle state, the sampled temperature in memory;

controlling, in the idle state, an internal electrical load to a first state;

receiving an actuation of a button;

in response to receiving the actuation, transitioning from the idle state to an awake state;

controlling, in the awake state, the internal electrical load to a second state, wherein the internal electrical load consumes more power in the second state than in the first state;

ceasing sampling of the temperature signal, in the awake state;

retrieving, in the awake state, the sampled temperature stored in the memory during the idle state;

comparing the retrieved sampled temperature to a set point temperature; and

based on comparing the retrieved sampled temperature to the set point temperature, controlling an HVAC system.

18. The method of claim 17, wherein controlling, in the idle state, the internal electrical load to the first state comprises decreasing a duty cycle of a button backlight circuit in response to a measured ambient light level.

19. The method of claim 17, wherein retrieving, in the awake state, the sampled temperature stored in the memory during the idle state comprises retrieving a most recent sampled temperature stored in the memory.