SINGLE LINE CONTROL FOR HVAC ACTUATOR

• US 20080058966A1
• Filed: 09/05/2006
• Published: 03/06/2008
• Est. Priority Date: 09/05/2006
• Status: Active Grant

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Wacker, Paul C.
• Granted Patent: US 7,787,994 B2
• Time in Patent Office: Days
• US Class Current: 700/57
• CPC Class Codes: H02P 23/0077 Characterised by the use of a particular software algorithm

Abstract

Methods and systems for controlling an HVAC actuator using a single output control signal are disclosed. In one illustrative embodiment, the single output control signal may be a digital signal that serially encodes desired position data (either an absolute position or a relative position) for the HVAC actuator. In some cases, the single output control signal is provided by a controller remote from the HVAC actuator, and is received by the HVAC actuator. The HVAC actuator may include a controller for decoding the serially encoded data contained in the single output control signal, and for controlling the HVAC actuator accordingly.

Claims

1. A controller for controlling a position of an HVAC actuator using a single output control signal, the controller comprising:

an output port; and

a processor for causing a serial bit stream to be impressed upon the single output control signal at the output port, wherein the serial bit stream encodes a value that is related to a desired position of the HVAC actuator;

wherein the HVAC actuator includes;

an actuated part;

a motor coupled to the actuated part, the motor adapted to drive the actuated part to various positions;

an input port coupled to the output port of the controller;

a second controller for receiving the serial bit stream that is impressed on the single output control signal at the input port; and

the second controller adapted to decode the serial bit stream and determine a desired position of the HVAC actuator, and provide one or more control signals to the motor to drive the actuated part to the desired position.

2. The controller of claim 1 wherein the serial bit stream encodes an absolute position of the HVAC actuator.

3. The controller of claim 1 wherein the serial bit stream encodes a relative position of the HVAC actuator.

4. The controller of claim 1 further comprising a switch, wherein the processor controls the switch, and the switch controls the serial bit stream that is impressed on the single output control signal at the output port.

5. The controller of claim 4 wherein the switch, when open, provides an AC signal on the single output control signal, and when closed, prevents the AC signal from reaching the single output control signal.

6. The controller of claim 4 wherein the switch, when open, provides a logic “

one”

on the single output control signal, and when closed, provides a logic “

zero”

on the single output control signal.

7. The controller of claim 4 wherein the switch, when open, provides a logic “

zero”

on the single output control signal, and when closed, provides a logic “

one”

on the single output control signal.

8. The controller of claim 4 wherein the switch is a Triac.

10. The controller of claim 1 wherein the motor is a DC brushless motor, and the second controller is adapted to control commutation of the motor.

9. (canceled)

11. An HVAC actuator, comprising:

an actuated part;

a motor coupled to the actuated part, the motor adapted to drive the actuated part to various positions;

an input port;

a controller for receiving a serial bit stream that is impressed on an input control signal at the input port, wherein the serial bit stream encodes a value that is related to a desired position of the HVAC actuator; and

the controller further adapted to decode the serial bit stream on the input control signal and determine a desired position of the HVAC actuator, and provide one or more control signals to the motor to drive the actuated part to the desired position.

12. The HVAC actuator of claim 11 wherein the motor is a DC brushless motor, and the controller is adapted to control commutation of the motor.

13. A method for controlling an HVAC actuator having a motor and an actuated part, the method comprising the steps of:

encoding a serial bit stream on a single output control signal, wherein the serial bit stream encodes a value that is related to a desired position of the HVAC actuator;

sending the encoded serial bit stream to the HVAC actuator;

decoding the serial bit stream to determine a desired position of the HVAC actuator; and

providing one or more control signals to the motor to drive the actuated part to the desired position.

14. The method of claim 13 wherein the decoding step is performed by a processor.

15. The method of claim 14 wherein the processor also controls commutation of the motor.

16. The method of claim 15 wherein the motor is a DC brushless motor.

17. The method of claim 13 wherein the encoding step includes selectively switching on and off a switch.

18. The method of claim 17 wherein the switch is a Triac, and a processor selectively switches the Triac on and off.

19. The method of claim 17 wherein the switch is a Triac, and a processor selectively switches the Triac on and off to encode the serial bit stream on the single output control signal.

20. The method of claim 19 wherein the switch is a Triac coupled to an AC signal, and the Triac passes the AC signal onto the single output control signal when the Triac is “

on” and

blocks the AC signal from reaching the single output control signal when the Triac is “

off”

.