Abstract: Methods and systems facilitate network communications between a wireless network-connected thermostat and a cloud-based management server in a manner that promotes reduced power usage and extended service life of an energy-storage device of the thermostat, while at the same time accomplishing timely data transfer between the thermostat and the cloud-based management server for suitable and time-appropriate control of an HVAC system. The thermostat further comprises powering circuitry configured to: extract electrical power from one or more HVAC control wires in a manner that does not require a “common” wire; supply electrical power for thermostat operation; recharge the energy-storage device (if needed) using any surplus extracted power; and discharge the energy-storage device to assist in supplying electrical power for thermostat operation during intervals in which the extracted power alone is insufficient for thermostat operation.

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.

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.

Abstract: A thermostat is described that includes a rechargeable battery, a graphical user interface and a wireless network communication capabilities. During installation, in cases where the rechargeable battery is below a first threshold, the installation procedure is limited so as to avoid energy intensive installation steps which may not be supported by the low battery level. An example of an installation step that is avoided due to low battery level is set up of wireless communication. According to some embodiments, if the battery level is very low during initial installation, the installation process is halted while the battery is charged. An indication such as a flashing LED may be displayed so as to indicate to the user that the battery is being charged.

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.

Abstract: Methods and systems facilitate network communications between a wireless network-connected thermostat and a cloud-based management server in a manner that promotes reduced power usage and extended service life of an energy-storage device of the thermostat, while at the same time accomplishing timely data transfer between the thermostat and the cloud-based management server for suitable and time-appropriate control of an HVAC system. The thermostat further comprises powering circuitry configured to: extract electrical power from one or more HVAC control wires in a manner that does not require a “common” wire; supply electrical power for thermostat operation; recharge the energy-storage device (if needed) using any surplus extracted power; and discharge the energy-storage device to assist in supplying electrical power for thermostat operation during intervals in which the extracted power alone is insufficient for thermostat operation.

Abstract: Methods and systems facilitate network communications between a wireless network-connected thermostat and a cloud-based management server in a manner that promotes reduced power usage and extended service life of a energy-storage device of the thermostat, while at the same time accomplishing timely data transfer between the thermostat and the cloud-based management server for suitable and time-appropriate control of an HVAC system. The thermostat further comprises powering circuitry configured to: extract electrical power from one or more HVAC control wires in a manner that does not require a “common” wire; supply electrical power for thermostat operation; recharge the energy-storage device (if needed) using any surplus extracted power; and discharge the energy-storage device to assist in supplying electrical power for thermostat operation during intervals in which the extracted power alone is insufficient for thermostat operation.

Abstract: An auxiliary hardware box is described that can be installed at or near the HVAC system. The auxiliary box includes a large number of wiring terminals, for example 16 or more, for connecting to a relatively large number of HVAC control wires. The auxiliary box can include a “train map” type graphic display that is visible to the installer and provides a graphical indication as to which relays or switches are currently open and which are currently closed. A small sleek visually pleasing thermostat is also described that can be connected either directly to an HVAC system or to the auxiliary box, and can automatically detect an purpose the connected wires according to which it is connected to.

Abstract: A thermostat for controlling an HVAC system in an enclosure may include a passive infrared sensor, an active infrared sensor, and an electronic display having a first mode and a second mode. The thermostat may also include one or more processors programmed to change a setpoint temperature of the thermostat to an energy-saving temperature upon detection of a non-occupancy condition for the enclosure. The processor(s) may detect the non-occupancy condition based at least in part on readings received from the passive infrared sensor. The processor(s) may also be programmed to change the electronic display from the first mode to the second mode upon detection of a person approaching the thermostat. The processor(s) may detect a person approaching the thermostat based at least in part on readings received from the active infrared sensor.

Abstract: In a multi-sensing, wirelessly communicating learning thermostat that uses power-harvesting to charge an internal power source, methods are disclosed for ensuring that the battery does not become depleted or damaged while at the same time ensuring selected levels of thermostat functionality. Charge status is monitored to determine whether the present rate of power usage needs to be stemmed. If the present rate of power usage needs to be stemmed, then a progression of performance levels and/or functionalities can be scaled back according to a predetermined progressive power conservation algorithm. In one embodiment, a wake-on-proximity function that activates a user interface based on readings from the proximity sensor may be altered while still allowing a HVAC control circuitry to operate as normal.

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.

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.

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 configured 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 powering circuit has a power extraction circuit configured to extract electrical power from one or more of the plurality of received HVAC control wires up to a first level of electrical power, a rechargeable battery, and a power control circuit. The power control circuit is configured to provide the electrical load power using power from the power extraction circuit and the rechargeable battery.

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.

Abstract: A thermostat is described that includes a rechargeable battery, a graphical user interface and a wireless network communication capabilities. During installation, in cases where the rechargeable battery is below a first threshold, the installation procedure is limited so as to avoid energy intensive installation steps which may not be supported by the low battery level. An example of an installation step that is avoided due to low battery level is set up of wireless communication. According to some embodiments, if the battery level is very low during initial installation, the installation process is halted while the battery is charged. An indication such as a flashing LED may be displayed so as to indicate to the user that the battery is being charged.

Abstract: A thermostat is described that includes a rechargeable battery, a graphical user interface and a wireless network communication capabilities. During installation, in cases where the rechargeable battery is below a first threshold, the installation procedure is limited so as to avoid energy intensive installation steps which may not be supported by the low battery level. An example of an installation step that is avoided due to low battery level is set up of wireless communication. According to some embodiments, if the battery level is very low during initial installation, the installation process is halted while the battery is charged. An indication such as a flashing LED may be displayed so as to indicate to the user that the battery is being charged.

Abstract: A thermostat for controlling an HVAC system in an enclosure may include a passive infrared sensor, an active infrared sensor, and an electronic display having a first mode and a second mode. The thermostat may also include one or more processors programmed to change a setpoint temperature of the thermostat to an energy-saving temperature upon detection of a non-occupancy condition for the enclosure. The processor(s) may detect the non-occupancy condition based at least in part on readings received from the passive infrared sensor. The processor(s) may also be programmed to change the electronic display from the first mode to the second mode upon detection of a person approaching the thermostat. The processor(s) may detect a person approaching the thermostat based at least in part on readings received from the active infrared sensor.

Abstract: An electronic thermostat and associated methods are disclosed for power stealing from an HVAC triggering circuit. The methods include making voltage measurements while controlling the amount of current drawn by the power stealing circuitry so as to determine a relationship that can be used to select how much current to draw during power stealing. Through the use of the described methods, the likelihood of inadvertent switching of the HVAC function (on or off) can be significantly reduced.

Abstract: A user-friendly, network-connected learning thermostat is described. The thermostat is made up of (1) a wall-mountable backplate that includes a low-power consuming microcontroller used for activities such as polling sensors and switching on and off the HVAC functions, and (2) separable head unit that includes a higher-power consuming microprocessor, color LCD backlit display, user input devices, and wireless communications modules. The thermostat also includes a rechargeable battery and power-stealing circuitry adapted to harvest power from HVAC triggering circuits. By maintaining the microprocessor in a “sleep” state often compared to the lower-power microcontroller, high-power consuming activities, such as learning computations, wireless network communications and interfacing with a user, can be temporarily performed by the microprocessor even though the activities use energy at a greater rate than is available from the power stealing circuitry.

Abstract: Methods and systems facilitate network communications between a wireless network-connected thermostat and a cloud-based management server in a manner that promotes reduced power usage and extended service life of a energy-storage device of the thermostat, while at the same time accomplishing timely data transfer between the thermostat and the cloud-based management server for suitable and time-appropriate control of an HVAC system. The thermostat further comprises powering circuitry configured to: extract electrical power from one or more HVAC control wires in a manner that does not require a “common” wire; supply electrical power for thermostat operation; recharge the energy-storage device (if needed) using any surplus extracted power; and discharge the energy-storage device to assist in supplying electrical power for thermostat operation during intervals in which the extracted power alone is insufficient for thermostat operation.