Adaptive power-stealing thermostat

Patent metadata

Field	Value
Publication number	US-10082307-B2
Application number	US-201615006969-A
Country	US
Kind code	B2
Filing date	Jan 26, 2016
Priority date	Sep 14, 2010
Publication date	Sep 25, 2018
Grant date	Sep 25, 2018

Abstract

A method of harvesting power from a heating, ventilation, and air conditioning (HVAC) system using an HVAC controller may include harvesting power from the HVAC system and measuring an electrical characteristic of the HVAC controller. The electrical characteristic may indicate whether the power harvested from the HVAC system is high enough to risk interfering with a normal operation of the HVAC system. The method may also include increasing the power harvested from the HVAC system until the electrical characteristic indicates that the HVAC controller is at risk of interfering with the normal operation of the HVAC system.

First claim

What is claimed is:

1. A method of harvesting power from a heating, ventilation, and air conditioning (HVAC) system using an HVAC controller, the method comprising:
harvesting, by the HVAC controller, power from the HVAC system;
measuring, by the HVAC controller, an electrical characteristic of the HVAC controller, wherein the electrical characteristic indicates whether the power harvested from the HVAC system is high enough to risk interfering with a normal operation of the HVAC system; and
increasing, by the HVAC controller, the power harvested from the HVAC system until the electrical characteristic indicates that the HVAC controller is at risk of interfering with the normal operation of the HVAC system.

2. The method of claim 1 , further comprising, in response to the electrical characteristic indicating that the HVAC controller is at risk of interfering with the normal operation of the HVAC system, decreasing the power harvested from the HVAC system until the electrical characteristic indicates that the HVAC controller is no longer at risk of interfering with the normal operation of the HVAC system.

3. The method of claim 1 , wherein the power harvested from the HVAC system is increased periodically by predetermined increments.

4. The method of claim 3 , wherein, following each increase in the power harvested from the HVAC system, a measurement of the electrical characteristic is made to determine whether the electrical characteristic indicates that the HVAC controller is at risk of interfering with the normal operation of the HVAC system.

5. The method of claim 1 , wherein interfering with the normal operation of the HVAC system comprises inadvertently causing an HVAC triggering circuit to activate an HVAC function.

6. The method of claim 1 , wherein interfering with the normal operation of the HVAC system comprises inadvertently causing an HVAC triggering circuit to deactivate an HVAC function.

7. The method of claim 1 , wherein the electrical characteristic comprises a voltage across a capacitor that stores charge from the power harvested from the HVAC system.

8. The method of claim 7 , wherein increasing the power harvested from the HVAC system comprises causing a programmable current controller to draw more current from the HVAC system.

9. The method of claim 8 , wherein the capacitor is in series between a voltage rectifier circuit and the programmable current controller.

10. The method of claim 1 , wherein the power harvested from the HVAC system is harvested from an HVAC triggering circuit of the HVAC system.

11. A heating, ventilation, and air conditioning (HVAC) controller comprising:
a power-harvesting circuit that harvests power from the HVAC system; and
a measurement circuit that measures an electrical characteristic of the HVAC controller, wherein the electrical characteristic indicates whether the power harvested from the HVAC system is high enough to risk interfering with a normal operation of the HVAC system;
wherein the power-harvesting circuit increases the power harvested from the HVAC system until the electrical characteristic indicates that the HVAC controller is at risk of interfering with the normal operation of the HVAC system.

12. The HVAC controller of claim 11 , wherein, in response to the electrical characteristic indicating that the HVAC controller is at risk of interfering with the normal operation of the HVAC system, the power harvesting circuit decreases the power harvested from the HVAC system until the electrical characteristic indicates that the HVAC controller is no longer at risk of interfering with the normal operation of the HVAC system.

13. The HVAC controller of claim 11 , wherein the power harvested from the HVAC system is increased periodically by predetermined increments.

14. The HVAC controller of claim 13 , wherein, following each increase in the power harvested from the HVAC system, a measurement of the electrical characteristic is made to determine whether the electrical characteristic indicates that the HVAC controller is at risk of interfering with the normal operation of the HVAC system.

15. The HVAC controller of claim 11 , wherein interfering with the normal operation of the HVAC system comprises inadvertently causing an HVAC triggering circuit to activate an HVAC function.

16. The HVAC controller of claim 11 , wherein interfering with the normal operation of the HVAC system comprises inadvertently causing an HVAC triggering circuit to deactivate an HVAC function.

17. The HVAC controller of claim 11 , wherein the electrical characteristic comprises a voltage across a capacitor that stores charge from the power harvested from the HVAC system.

18. The HVAC controller of claim 17 , wherein increasing the power harvested from the HVAC system comprises causing a programmable current controller to draw more current from the HVAC system.

19. The HVAC controller of claim 18 , wherein the capacitor is in series between a voltage rectifier circuit and the programmable current controller.

20. The HVAC controller of claim 11 , wherein the power harvested from the HVAC system is harvested from an HVAC triggering circuit of the HVAC system.

Assignees

• Google Llc

Inventors

• Warren Daniel Adam
• Smith Ian C
• Satterthwaite Jr Edwin H
• Palmer Joseph E

Classifications

• F24F11/89

  Arrangement or mounting of control or safety devices · CPC title

• G05D23/19

  characterised by the use of electric means {(G05D23/1393 takes precedence)} · CPC title

• F24F11/52

  Indication arrangements, e.g. displays · CPC title

• F24F11/56

  Remote control · CPC title

• G05B13/0265

  the criterion being a learning criterion · CPC title