Power management in single circuit hvac systems and in multiple circuit hvac systems

Patent metadata

Field	Value
Publication number	US-2016363942-A1
Application number	US-201615248725-A
Country	US
Kind code	A1
Filing date	Aug 26, 2016
Priority date	Nov 19, 2010
Publication date	Dec 15, 2016
Grant date	—

Abstract

A thermostat includes a plurality of HVAC (heating, ventilation, and air conditioning) wire connectors for receiving a plurality of HVAC control wires corresponding to an HVAC system. The thermostat also includes a thermostat processing and control circuit operative to at least partially control the operation of the HVAC system and a powering circuit coupled to the HVAC wire connectors and configured to provide an electrical load power to the thermostat processing and control circuit. The thermostat includes circuitry and methods for maximizing efficiency of energy harvested from the HVAC system connected to the thermostat, and depending on which system is connected to the thermostat, different power schemes can be implemented in order to obtain power from the HVAC system.

First claim

1 .- 27 . (canceled)

28 . A thermostat for use in connection with a HVAC (heating, ventilation, and air conditioning) system, the HVAC system having a single circuit system, a multiple circuit system, or a common wire system, the thermostat comprising:
insertion sensing circuitry operative to provide insertion sensing signals indicative of a wiring scheme associated with the HVAC system being connected to the thermostat; and control circuitry operative to:
receive the insertion sensing signals; and
engage in single circuit power stealing, multi-circuit power stealing, or common wire power utilization for obtaining power from the HVAC system based on the received insertion sensing signals, wherein:
the single circuit power stealing is characterized by using both active and inactive power stealing from a single HVAC control wire;
the multi-circuit power stealing scheme is characterized by only using inactive power stealing on a non-enabled circuit within the multiple circuit system; or
the common wire system is characterized by using neither active power stealing nor inactive power stealing.

29 . The thermostat of claim 28 , wherein the active power stealing is characterized in harvesting power from the HVAC system while it is engaged in an active HVAC function.

30 . The thermostat of claim 28 , further comprising a switching circuit for controlling a HVAC function, wherein a closed switching circuit activates the HVAC function, wherein the active power stealing is performed during times when the HVAC function is active, wherein during active power stealing, the switching circuit opens for a time interval, wherein:
power is harvested from the HVAC system during the time interval; and the time interval is short enough that the HVAC function remains active without interruption during the time interval.

31 . The thermostat according to claim 28 , wherein active power stealing is characterized by momentarily opening a closed contact during an enabled phase of the single circuit system.

32 . The thermostat according to claim 31 , wherein the contact is closed during a majority of each duty cycle when the single circuit system is in the enabled phase.

33 . The thermostat according to claim 28 , wherein active power stealing is characterized by receiving power from an enabled HVAC relay circuit in a manner that does not untrip the enabled HVAC relay circuit.

34 . The thermostat according to claim 28 , wherein inactive power stealing is characterized by receiving power from a non-enabled HVAC relay circuit in a manner that does not trip the non-enabled HVAC relay circuit.

35 . A thermostat for use in connection with a HVAC (heating, ventilation, and air conditioning) system, the HVAC system having a single circuit system, a multiple circuit system, or a common wire system, the thermostat comprising:
insertion sensing circuitry operative to provide insertion sensing signals indicative of a wiring scheme associated with the HVAC system being connected to the thermostat; and control circuitry operative to:
receive the insertion sensing signals; and
engage in single circuit power stealing, multi-circuit power stealing, or common wire power utilization for obtaining power from the HVAC system based on the received insertion sensing signals, wherein:
the single circuit power stealing is characterized by using both active and inactive power stealing from a single HVAC control wire, wherein active power stealing is characterized in harvesting power from the HVAC system by fast switching a transistor;
the multi-circuit power stealing scheme is characterized by only using inactive power stealing on a non-enabled circuit within the multiple circuit system, wherein inactive power stealing is characterized in harvesting power from the HVAC system by not fast switching the transistor; or
the common wire system is characterized by using neither active power stealing nor inactive power stealing.

36 . The thermostat of claim 35 , wherein an HVAC function is activated when the transistor is closed, wherein the active power stealing is performed during times when the HVAC function is active, wherein during active power stealing, the transistor opens for a time interval, wherein:
power is harvested from the HVAC system during the time interval; and the time interval is short enough that the HVAC function remains active without interruption during the time interval.

37 . The thermostat of claim 36 , wherein a length of the time interval is determined by:
monitoring a voltage associated with a charge level of a capacitive element; beginning the time interval when the voltage is below a lower threshold; charging the capacitive element during the time interval; and ending the time interval when the voltage exceeds an upper threshold.

38 . A thermostat for use in connection with a HVAC (heating, ventilation, and air conditioning) system, the HVAC system having a single circuit system, a multiple circuit system, or a common wire system, the thermostat comprising:
insertion sensing circuitry operative to provide insertion sensing signals indicative of a wiring scheme associated with the HVAC system being connected to the thermostat; and control circuitry operative to:
receive the insertion sensing signals; and
engage in single circuit power stealing, multi-circuit power stealing, or common wire power utilization for obtaining power from the HVAC system based on the received insertion sensing signals, wherein:
the single circuit power stealing is characterized by using both active and inactive power stealing from a single HVAC control wire, wherein active power stealing is characterized in harvesting power from the HVAC system by duty cycling a field effect transistor;
the multi-circuit power stealing scheme is characterized by only using inactive power stealing on a non-enabled circuit within the multiple circuit system, wherein inactive power stealing is characterized in harvesting power from the HVAC system by not duty cycling switching the field effect transistor; or
the common wire system is characterized by using neither active power stealing nor inactive power stealing.

Assignees

• Google Inc

Inventors

• Warren Daniel Adam
• Fiennes Hugo B
• Dutra Jonathan Alan
• Bell David
• Fadell Anthony Michael
• Rogers Matthew Lee
• Smith Ian C
• Satterthwaite Jr Edwin H
• Erickson Grant Michael
• Mucignat Andrea
• Palmer Joseph E

Classifications

• G05B2219/2614

  HVAC, heating, ventillation, climate control · CPC title

• F24F11/61

  using timers · CPC title

• F24F2120/14

  Activity of occupants · CPC title

• F24F11/30

  for purposes related to the operation of the system, e.g. for safety or monitoring · CPC title

• F24F2110/10

  Temperature · CPC title