Thermostat circuitry to control power usage

Patent metadata

Field	Value
Publication number	US-9857091-B2
Application number	US-201314088312-A
Country	US
Kind code	B2
Filing date	Nov 22, 2013
Priority date	Nov 22, 2013
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

An operation alteration of a network attached thermostat to control power usage. Control wires for a heating and air conditioning system may be connected to a thermostat control circuit configured to control the system. A power extraction circuit may be coupled to the control wires configured to extract power from the control wires. The power may be put into a storage device. The power may be provided to the thermostat control circuit and a WiFi radio module. The radio module may provide a network connection for the thermostat. Circuitry and techniques may be provided to reduce power usage by the thermostat components.

First claim

What is claimed is:

1. A thermostat comprising:
control wires that control heating, ventilation and air conditioning (HVAC) equipment;
a thermostat control circuit configured to control the HVAC equipment;
a radio module coupled to the thermostat control circuit to provide a network connection for the thermostat; and
a power circuit system coupled to the control wires and providing power to the thermostat control circuit and the radio module; and
wherein the power circuit system comprises:
an extraction circuit configured to extract power from the control wires;
a power storage device configured to store electrical current extracted from the control wires;
common wire detection circuitry configured to detect a presence of a common wire among the control wires; and
load determination circuitry configured to determine the electrical load impedance presented by HVAC equipment;

wherein the thermostat control circuit comprises:
a rules table that correlates thermostat operation to power parameters, the rules table including statements comprising:
if the common wire is absent and the amount of power that can be extracted from the control wires is high, the thermostat control circuit uses more power than when the amount of power that can be extracted from the control wires is normal;
if the common wire is absent and the amount of power that can be extracted from the control wires is low, the thermostat control circuit uses less power than when the amount of power that can be extracted from the control wires is normal; and
wherein high is greater than normal and normal is greater than low; and

wherein the radio module comprises TCP/IP configured to contain networking constants that control socket timeouts and the socket timeouts are adjusted based, at least in part, on a determined electrical load impedance presented by the HVAC equipment.

2. The thermostat of claim 1 , wherein the power circuit system further comprises:
a rules table correlating the amount of power that can be extracted from the control wires with the load impedance of the HVAC equipment for determining the amount of power stored in the power storage device; and
a communications protocol used for communications with the thermostat control circuit and the radio module; and
wherein messages are sent using the communications protocol that informs the thermostat control circuit and radio module of power parameters incorporating presence of the common wire, a charge on the power storage device and an amount of power that can be extracted from the HVAC equipment.

3. The thermostat of claim 1 , wherein the thermostat control circuit comprises:
circuitry configured to control the HVAC equipment;
a display;
circuitry configured to show user information on the display;
circuitry configured to illuminate the display; and
software configured to alter power used by changing the user information and an amount and time of illumination of the display.

4. The thermostat of claim 1 , wherein the rules table further comprises one or more statements of a group consisting of:
if the common wire is present, the thermostat control circuit uses more power than if the common wire is absent;
if the common wire is absent, and the charge on the power storage device is high, the thermostat control circuit uses more power than when the charge on the power storage device is normal; and
if the common wire is absent present, and the charge on the power storage device is low, the thermostat control circuit uses less power than when the charge on the power storage device is normal.

5. The thermostat of claim 1 , wherein the radio module comprises:
circuitry configured to communicate with a WiFi router;
networking algorithms to communication through the WiFi router with a central server;
software configured to group virtually all tasks to be performed in time;
software configured to perform tasks periodically;
software configured to create network channels for transfer of HVAC information between the thermostat control circuit and the central server;
software configured to abort network communications;
software configured to alter the power used by changing the task period, networking constants, allowing or disallowing network channels and aborting network communications; and
a rules table that correlates thermostat operation to power parameters.

6. The thermostat of claim 5 , wherein the rules table comprises one or more statements of a group consisting of:
if the common wire is present, the WiFi radio module uses more power than if the common wire is absent;
if the common wire is not present, and the amount of power that can be extracted from the control wires is high, the WiFi radio module uses more power than when the amount of power is normal;
if the common wire is not present, and the amount of power that can be extracted from the control wires is low, the WiFi radio module uses less power than when the amount of power that can be extracted from the control wires is normal;
if the common wire is not present, and the charge on the power storage device is high, the WiFi radio module uses more power than when the charge on the power storage device is normal;
if the common wire is not present, and the charge on the power storage device is low, the WiFi radio module uses less power than when the charge on the power storage is normal; and
high is greater than normal and normal is greater than low.

7. A method for altering operation of a network attached thermostat to control power usage, comprising:
providing a thermostat for controlling HVAC equipment, wherein:
the thermostat comprises a radio module, a power circuit, and a control circuit; and
the radio module comprises a processor and radio chip;

determining when a next communication task of the radio module will be ready;
comparing a time until the next communication task of the radio module will be ready to a threshold amount of time; and
if the time until the next communication task of the radio module exceeds the threshold amount of time, putting the processor into a stop mode and the radio chip into a power save mode to reduce power in the radio module until the time until the next communication task of the radio module will be ready has expired;
wherein the radio module comprises TCP/IP configured to contain networking constants that control socket timeouts and the socket timeouts are adjusted based, at least in part, on a determined electrical load impedance presented by the HVAC equipment.

8. The method of claim 7 , further comprising:
communicating with a server using the radio module.

9. The method of claim 7 , further comprising:
communicating with a server using the radio module; and
wherein:
communicating with the server comprises:
when thermostat data have changed, the data are sent to the server;
a data session is had with the server; or
there is a performance of a ping check-in as a TCP packet sent to the server.

10. The method of claim 7 , further comprising:
providing power from the power circuit to the radio module; and
wherein:
the power circuit draws a first amount of power from a voltage line when the HVAC equipment is on;
the power circuit extracts a second amount of power when the HVAC equipment is off; and
the first amount of power is greater than the second amount of power.

11. The method of claim 10 , wherein the second amount of power that the power circuit can extract varies inversely with a load impedance with the HVAC equipment off.

12. The method of claim 11 , further comprising:
using the second amount of power to provide a charge to a super capacitor; and
wherein th

Assignees

• Honeywell Int Inc

Inventors

• Robideau Kurt
• Lemire Patrick R
• Juntunen Robert D

Classifications

• F24F11/58

  using Internet communication · CPC title

• F24F11/52

  Indication arrangements, e.g. displays · CPC title

• F24F11/46 Primary

  Improving electric energy efficiency or saving · CPC title

• F24F2011/0071

  Mechanical Engineering · mapped topic

• F24F11/0086 Primary

  Mechanical Engineering · mapped topic