MONITORING AND RECOVERABLE PROTECTION OF THERMOSTAT SWITCHING CIRCUITRY

• US 20140175181A1
• Filed: 12/13/2013
• Published: 06/26/2014
• Est. Priority Date: 09/21/2012
• Status: Active Grant

• Current Assignee: Google LLC (Alphabet Inc.)
• Original Assignee: Nest Labs Incorporated (Alphabet Inc.)
• Inventors: Warren, Daniel Adam, Conner, Brian J., Smith, Ian C.
• Granted Patent: US 9,935,455 B2
• Time in Patent Office: Days
• US Class Current: 236/51
• CPC Class Codes: F24D 5/02 operating with discharge of hot air into the space or area to be heated
• CPC Class Codes: F24D 5/12 using heat pumps
• CPC Class Codes: G01R 31/74 Testing of fuses
• CPC Class Codes: G05D 23/19 characterised by the use of electric means G05D23/1393 takes precedence
• CPC Class Codes: G05D 23/1902 characterised by the use of a variable reference value
• CPC Class Codes: H01H 2300/03 Application domotique, e.g. for house automation, bus connected switches, sensors, loads or intelligent wiring
• CPC Class Codes: H01H 85/0241 Structural association of a fuse and another component or apparatus switches with built-in fuses H01H9/10, spark-gap arresters H01H85/44, transformers and inductances H01F27/402, capacitors H01G2/14, lamps H01K1/66, semiconductors H01L23/5256 or H01L23/62
• CPC Class Codes: H01H 85/32 Indicating lamp structurally associated with the protective device
• CPC Class Codes: H02H 7/20 for electronic equipment for converters H02H7/10; for electric measuring instruments G01R1/36; for dc voltage or current semiconductor regulators G05F1/569; for amplifiers H03F1/52; for electronic switching circuits H03K17/08
• CPC Class Codes: H05B 1/0205 using a fusible material
• CPC Class Codes: Y02B 30/13 Hot air central heating systems using heat pumps
• CPC Class Codes: Y02B 90/20 Smart grids as enabling technology in buildings sector smart grids supporting the management or operation of end-user stationary applications in general, or like technologies with no associated climate change mitigation effect Y04S20/00
• CPC Class Codes: Y04S 20/14 Protecting elements, switches, relays or circuit breakers

Abstract

A method of automated sensing of an electrical anomaly associated with a thermostat may include switching a switching circuit within the thermostat to an on state. The switching circuit may be configured to activate an HVAC function when switched to the on state. The method may also include monitoring one or more electrical properties associated with the switching circuit. The method may additionally include determining if an electrical anomaly is associated with the switching circuit based at least in part on the monitored one or more electrical properties. The method may further include switching the switching circuit to an off state if an electrical anomaly is detected.

Claims

1-25. -25. (canceled)

26. A method of automated sensing of an electrical anomaly associated with a thermostat, the method comprising:

switching a switching circuit within the thermostat to an on state, the switching circuit configured to activate an HVAC function when switched to the on state;

monitoring one or more electrical properties associated with the switching circuit;

determining if an electrical anomaly is associated with the switching circuit based at least in part on the monitored one or more electrical properties; and

switching the switching circuit to an off state if an electrical anomaly is detected.

27. A method according to claim 26, wherein the electrical anomaly comprises excessive current through the switching circuit.

28. A method according to claim 26, further comprising:

determining that an anomalous wiring condition is present; and

causing a message to be transmitted to a user device indicating the anomalous wiring condition.

29. A method according to claim 28, wherein the message is transmitted using technology of a type selected from a group consisting of:

transmission to a web application for viewing on a computer, transmission to a mobile application for viewing on a smart phone, and transmission to a mobile application for viewing on a tablet computer.

30. A method according to claim 26, further comprising causing information to be transmitted to a manufacturer of the thermostat indicating the electrical anomaly.

31. A method according to claim 30, wherein the information transmitted to the manufacturer includes diagnostic information that facilitates a diagnosis performed by the manufacturer of the thermostat.

32. A method according to claim 31, further comprising displaying a message on a user interface of the thermostat, the message offering expert assistance based at least in part on the diagnosis performed by the manufacturer of the thermostat.

33. A thermostat comprising:

a switching circuit configured to operate in an on state and an off state, the switching circuit further configured to activate an HVAC function when switched to the on state;

a monitoring circuit configured to monitor one or more electrical properties associated with the switching circuit; and

a processor coupled to the switching circuit and the monitoring circuit, the processor being programmed to;

cause the switching circuit to switch to the on state to activate the HVAC function;

determine if an electrical anomaly associated with the switching circuit is present based at least in part on the monitored one or more electrical properties provided by the monitoring circuit; and

cause switching circuit to switch to the off state if an electrical anomaly is detected.

34. A thermostat according to claim 33, wherein the switching circuit comprises a first Field Effect Transistor (FET).

35. A thermostat according to claim 34, wherein the monitored one or more electrical properties includes a voltage level of a node associated with a drain of the first FET.

36. A thermostat according to claim 34, wherein the switching circuit comprises a second FET that is switched on and off with the first FET.

37. A thermostat according to claim 33, wherein the processor is further programmed to determine if the electrical anomaly is caused by an anomalous wiring condition.

38. A thermostat according to claim 37, further comprising a user interface, wherein the processor is further programmed to display an error message on the user interface indicating the anomalous wiring condition.

39. A thermostat according to claim 33, wherein the processor is further programmed to:

determine if the electrical anomaly has been corrected; and

subsequent to the determination of the correction, cause the switching circuit to switch to the on state.

40. A thermostat comprising:

a first Field Effect Transistor (FET);

a second FET, wherein;

the first FET and the second FET are connected in series; and

turning on the first FET and the second FET activates an HVAC function;

a monitoring circuit that monitors the voltage level at a node between the first FET and the second FET to detect when the voltage level surpasses a threshold voltage;

a processor that is programmed to;

cause the first FET and the second FET to turn on and activate the HVAC function;

receive an indication from the monitoring circuit that an electrical anomaly is present based on the voltage level surpassing the threshold voltage; and

cause the first FET and the second FET to turn off when the electrical anomaly is present.

41. A thermostat according to claim 40, wherein the monitoring circuit electrically isolates the processor from a 24VAC voltage line of an HVAC system.

42. A thermostat according to claim 40, wherein the monitoring circuit is powered by a differential clock signal from the processor.

43. A thermostat according to claim 40, wherein the voltage level surpassing the threshold voltage indicates excessive current in the first or second FET.

44. A thermostat according to claim 40, wherein the processor comprises a backplate microprocessor that communicates with a head unit microprocessor.

45. A thermostat according to claim 40, wherein the thermostat further comprises a wireless communication module configured to communicate with a cloud-based thermostat management server.