Thermostat with wiring terminals configured for spatial compactness and ease of wire installation

Abstract

A wall-mountable programmable electronic thermostat for controlling an HVAC system is described. The thermostat includes a circular wall-mountable backplate with a central opening to allow for the passage of HVAC wires for electrical connection to the thermostat. The head unit body is also circular and is removeably mountable to the back plate. A plurality of wedge-shaped wiring terminals are mounted on the backplate for making a tool-free connection to HVAC wires. Each wiring terminal has button that a user can depress while a wire is inserted in a wire hole. The terminals are arranged along one or more circular arcs about the central opening of the backplate such that the wire holes face the central opening and the buttons are located close to the outer periphery of the backplate.

What is claimed is: 
     
         1 . A thermostat for controlling an HVAC system comprising:
 a backplate adapted to be mounted on a wall, the backplate having a central opening to allow for insertion a plurality of HVAC wires through the backplate for electrical connection to the thermostat, the central opening being large enough to allow a user's fingers to insert the plurality of HVAC wires through the central opening;   a head unit including a display for displaying information to a user, the head unit being removeably mountable to the back plate;   a plurality of wiring terminals each configured to make an electrical connection with an HVAC wire, the plurality of wiring terminals being mounted on the backplate and arranged along one or more arcs about the central opening of the backplate, each wiring terminal having a wire hole facing the central opening; and   a connection sensing module coupled to said plurality of wiring terminals, said connection sensing module being configured to determine the identities of a first subset of the plurality of wiring terminals into which corresponding HVAC wires have been inserted so as to determine a configuration of the HVAC system to be controlled.   
     
     
         2 . The thermostat of  claim 1 , further comprising a processing system disposed within the housing, the processing system being configured to process said identities of said first subset of wiring terminals to determine a configuration of the HVAC system to be controlled. 
     
     
         3 . The thermostat of  claim 2 , wherein the processing system is in operative communication with one or more temperature sensors for determining an ambient air temperature, in operative communication with one or more input devices for determining a setpoint temperature value, and in still further operative communication with the HVAC system to control the HVAC system based at least in part on a comparison of a measured ambient temperature and the setpoint temperature value. 
     
     
         4 . The thermostat of  claim 1 , wherein each wiring terminal includes a button member positioned nearer to an outer periphery of the backplate than said wire hole, said button member being operable by said user to make an electrical connection with the HVAC wire without the use of tools by pressing the button member on the wiring terminal and inserting the HVAC wire into the wire hole's fingers to enable insertion of the HVAC wire into the wiring terminal. 
     
     
         5 . The thermostat of  claim 4 , further comprising a backplate cover configured to cover the backplate, the backplate cover having a plurality of openings through which said button members protrude to allow access thereto by said user's fingers, whereby the user can access said button members without their fingers coming into contact with said backplate. 
     
     
         6 . The thermostat of  claim 4 , wherein each of the wiring terminals is generally wedge-shaped having the wire hole facing the central opening and the button member being positioned near the outer periphery of the backplate circuit board. 
     
     
         7 . The thermostat of  claim 1 , wherein each of the wiring terminals is configured such that the physical presence of a wire inserted into the wiring terminal can be mechanically detected. 
     
     
         8 . The thermostat of  claim 7 , wherein the mechanical detection includes switching of a loop of an electrical circuit that does not include the inserted HVAC wire. 
     
     
         9 . The thermostat of  claim 1 , wherein each wiring terminal is positioned on the backplate such that the distance from the center of the central opening to each wire hole is equivalent. 
     
     
         10 . A thermostat comprising:
 a backplate including a backplate circuit board, the backplate circuit board having a plurality of electrical components mounted thereon, the backplate adapted for mounting on a wall, the backplate circuit board having a central opening that is large enough to allow a user's fingers to insert a plurality of HVAC wires through the central opening for electrical connection to the thermostat;   a head unit including a display for displaying information to a user, the head unit being removeably mountable to the back plate;   a plurality of wiring terminals each configured to make an electrical connection with an HVAC wire, the plurality of wiring terminals being mounted on the backplate circuit board and arranged along one or more arcs about the central opening of the backplate circuit board, each wiring terminal having a wire hole facing the central opening;   a connection sensing module coupled to said plurality of wiring terminals, said connection sensing module being configured to determine the identities of a first subset of the plurality of wiring terminals into which corresponding HVAC wires have been inserted so as to determine a configuration of the HVAC system to be controlled; and   a processing system disposed within the housing, the processing system being configured to process said identities of said first subset of wiring terminals to determine a configuration of the HVAC system to be controlled.   
     
     
         11 . The thermostat of  claim 10 , wherein the wiring terminals include a button member positioned nearer to an outer periphery of the backplate circuit board than said wire hole, the wiring terminals being configured to allow the user to make an electrical connection with the HVAC wire without the use of tools by pressing the button member and inserting the HVAC wire into the wire hole. 
     
     
         12 . The thermostat of  claim 11 , further comprising a backplate cover configured to cover said plurality of electrical components, the backplate cover having a plurality of openings through which said button members protrude to allow access thereto by the user's fingers such that the user can access said button members without their fingers coming into contact with said electrical components. 
     
     
         13 . The thermostat of  claim 11 , wherein the wire hole and the button member are on opposite sides of the wiring terminal, and the wiring terminal is generally wedge-shaped such that the side of the terminal including the wire hole is shorter than a side of the terminal including the button member. 
     
     
         14 . The thermostat of  claim 10 , wherein the processing system is in operative communication with one or more temperature sensors for determining an ambient air temperature, in operative communication with one or more input devices for determining a setpoint temperature value, and in still further operative communication with the HVAC system to control the HVAC system based at least in part on a comparison of a measured ambient temperature and the setpoint temperature value. 
     
     
         15 . A thermostat comprising:
 a backplate including a backplate circuit board, the backplate circuit board having a plurality of electrical components mounted thereon, the backplate adapted for mounting on a wall, the backplate circuit board having a central opening that is large enough to allow a user's fingers to insert a plurality of HVAC wires through the central opening for electrical connection to the thermostat;   a head unit including a display for displaying information to a user, the head unit being removeably mountable to the back plate;   a plurality of wiring terminals each configured to make an electrical connection with an HVAC wire, the plurality of wiring terminals being mounted on the backplate circuit board and arranged along one or more arcs about the central opening of the backplate circuit board, each wiring terminal having a wire hole facing the central opening; and   a connection sensing module coupled to said plurality of wiring terminals, said connection sensing module being configured to determine the identities of a first subset of the plurality of wiring terminals into which corresponding HVAC wires have been inserted so as to determine a configuration of the HVAC system to be controlled.   
     
     
         16 . The thermostat of  claim 15 , further comprising a processing system disposed within the housing, the processing system being configured to process said identities of said first subset of wiring terminals to determine a configuration of the HVAC system to be controlled. 
     
     
         17 . The thermostat of  claim 16 , wherein the processing system is in operative communication with one or more temperature sensors for determining an ambient air temperature, in operative communication with one or more input devices for determining a setpoint temperature value, and in still further operative communication with the HVAC system to control the HVAC system based at least in part on a comparison of a measured ambient temperature and the setpoint temperature value. 
     
     
         18 . The thermostat of  claim 15 , wherein the wiring terminals include a button member positioned nearer to an outer periphery of the backplate circuit board than said wire hole, the wiring terminals being configured to allow the user to make an electrical connection with the HVAC wire without the use of tools by pressing the button member and inserting the HVAC wire into the wire hole. 
     
     
         19 . The thermostat of  claim 18 , further comprising a backplate cover configured to cover said plurality of electrical components, the backplate cover having a plurality of openings through which said button members protrude to allow access thereto by the user's fingers such that the user can access said button members without their fingers coming into contact with said electrical components. 
     
     
         20 . The thermostat of  claim 18 , wherein the wire hole and the button member are on opposite sides of the wiring terminal, and the wiring terminal is generally wedge-shaped such that the side of the terminal including the wire hole is shorter than a side of the terminal including the button member.