Furnace control board architecture

Patent metadata

Field	Value
Publication number	US-9946239-B2
Application number	US-201514843620-A
Country	US
Kind code	B2
Filing date	Sep 2, 2015
Priority date	Sep 2, 2015
Publication date	Apr 17, 2018
Grant date	Apr 17, 2018

Abstract

A system and method are disclosed that provide for a dual processor architecture in a furnace or HVAC controller. One processor can control non-safety-critical components and is operable to receive software updates. The other processor can control safety-critical components and is not capable of being updated. Safety-critical components can comprise a flame sensor, gas valve and an igniter.

First claim

What is claimed is:

1. A controller board for a furnace comprising:
a communication interface comprising a connection to a central HVAC controller;
an application processor comprising a memory and a connection to a plurality of non-safety-critical components, the application processor able to process software updates for the non-safety-critical components;
a safety processor comprising a memory and a connection to a flame sensor, a gas valve, and an igniter, wherein the safety processor and associated software are not updateable; and
an interprocessor interface comprising a connection between the application processor and the safety processor.

2. The controller board of claim 1 further comprising a motor controller, the motor controller in communication with the application processor and the safety processor.

3. The controller board of claim 1 wherein the application processor and the safety processor both comprise a UART.

4. The controller board of claim 1 wherein the application processor comprises a connection to an air sensor.

5. The controller board of claim 1 further comprising a read-only memory.

6. The controller board of claim 1 wherein the application processor comprises a connection to a humidifier.

7. The controller board of claim 1 wherein the application processor comprises a connection to an HVAC accessory.

8. The controller board of claim 1 wherein the application processor comprises a connection to an air filter.

9. A controller board for an HVAC system comprising:
a communication interface operable to communicate with a plurality of servers;
a connection to a thermostat;
an application processor comprising a memory and operable to receive a software update from the plurality of servers, the application processor further comprising a connection to a plurality of non-safety-critical components, the application processor able to process software updates for the non-safety-critical components;
a safety processor comprising a memory and a connection to a flame sensor, a gas valve, and an igniter, wherein the safety processor and associated software are not updateable; and
an interprocessor interface comprising a connection between the application processor and the safety processor.

10. The controller board of claim 9 further comprising a motor controller, the motor controller in communication with the application processor and the safety processor.

11. The controller board of claim 9 wherein the application processor and the safety processor both comprise a UART.

12. The controller board of claim 9 wherein the application processor comprises a connection to an air sensor.

13. The controller board of claim 9 further comprising a read-only memory.

14. The controller board of claim 9 wherein the application processor comprises a connection to a humidifier.

15. The controller board of claim 9 wherein the application processor comprises a connection to an HVAC accessory.

16. The controller board of claim 9 wherein the application processor comprises a connection to an air filter.

17. A method of manufacturing a furnace controller for an HVAC system comprising:
providing a controller board;
providing an application processor, the application processor comprising a memory and a connection to a central HVAC controller, the application processor operable to receive a software update;
providing a safety processor, the safety processor comprising a memory and a connection to a flame sensor, a gas valve, and an igniter; and
providing an interprocessor interface comprising a connection between the application processor and the safety processor.

18. The method of claim 17 further comprising providing a motor controller.

19. The method of claim 17 wherein the connection to the central HVAC controller is wireless.

20. The method of claim 17 further comprising connecting the application processor to non-safety-critical components of the furnace.

Assignees

• Lennox Ind Inc

Inventors

• Sakai Takeshi
• Engler Michael
• Vendt Stephen J

Classifications

• F24F11/0086

  Mechanical Engineering · mapped topic

• G05B15/02 Primary

  electric · CPC title

• F24F11/63

  Electronic processing · CPC title

• F24F11/58

  using Internet communication · CPC title

• F24F11/52

  Indication arrangements, e.g. displays · CPC title