Apparatus and methods for power stealing by controllers

• US 9,841,203 B2
• Filed: 11/10/2014
• Issued: 12/12/2017
• Est. Priority Date: 07/17/2014
• Status: Active Grant

• Current Assignee: Copeland Comfort Control LP (Emerson Electric Company)
• Original Assignee: Emerson Electric Company
• Inventors: Pawar, Harshal Manik
• Primary Examiner(s): Wu, Qing Yuan
• Application Number:
  US14/536,922
• Publication Number:
  US 20160018836A1
• Time in Patent Office: 1,128 Days
• Field of Search: None
• CPC Class Codes: F24F 11/30 for purposes related to the operation of the system, e.g. for safety or monitoring
• CPC Class Codes: F24F 11/49 ensuring correct operation, e.g. by trial operation or configuration checks
• CPC Class Codes: F24F 11/62 characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
• CPC Class Codes: F24F 11/63 Electronic processing
• CPC Class Codes: F24F 2110/00 Control inputs relating to air properties
• CPC Class Codes: G05D 23/1902 characterised by the use of a variable reference value
• CPC Class Codes: G05D 23/1919 characterised by the type of controller
• CPC Class Codes: G05F 1/66 Regulating electric power
• CPC Class Codes: H02M 5/00 Conversion of ac power input into ac power output, e.g. for change of voltage, for change of frequency, for change of number of phases
• CPC Class Codes: H02M 7/00 Conversion of ac power input into dc power output; Conversion of dc power input into ac power output

Abstract

A controller for use in a climate control system includes a power stealing circuit connectible with a control of the climate control system and configured for stealing power via a signal from a power source through the control. An overcurrent limiting circuit is configured to limit a first portion of the signal to prevent a false call for operation of the control. The overcurrent limiting circuit is further configured not to limit a second portion of the signal to prevent a false call, where the control is configured to recognize only the first portion as determinative of whether the signal is a call for operation.

Claims

1. A controller configured for use in a climate control system, the controller comprising:

a power stealing circuit configured to be connectible with a control of the climate control system and configured for stealing power from a power source via a signal through the control, without using a common (C) wire from the power source and an RC/RH line where power is drawn when a relay switch in the controller is opened/closed; and

an overcurrent limiting circuit configured to limit a first portion of the signal to prevent a false call for operation of the control;

the overcurrent limiting circuit further configured not to limit a second portion of the signal to prevent a false call, where the control is configured to recognize only the first portion as determinative of whether the signal is a call for operation;

wherein the first portion is a positive portion of the signal and the second portion is a negative portion of the signal.

2. The controller of claim 1, wherein the controller comprises a thermostat.

3. The controller of claim 1, wherein the power stealing circuit is configured to steal power via the first and second portions of the signal when the signal is determined not to be a call for operation.

4. The controller of claim 1, wherein the power stealing circuit is configured to steal power via the second portion of the signal when the signal is determined to be a call for operation.

5. A controller configured for use in a climate control system, the controller comprising:

a power stealing circuit configured to be connectible with a control of the climate control system and configured for stealing power from a power source via a signal through the control, without using a common (C) wire from the power source and an RC/RH line where power is drawn when a relay switch in the controller is opened/closed;

an overcurrent limiting circuit configured to limit a first portion of the signal to prevent a false call for operation of the control, the overcurrent limiting circuit further configured not to limit a second portion of the signal to prevent a false call, where the control is configured to recognize only the first portion as determinative of whether the signal is a call for operation; and

a call generator configured to provide a call for operation of the control, the call including a signal portion configured to be unrecognized by the control as determinative of whether the signal is a call for operation and to provide a voltage for driving power stealing by the power stealing circuit.

6. The controller of claim 5, wherein the first portion is a positive portion of the signal and the second portion is a negative portion of the signal.

7. The controller of claim 5, wherein the call is a call for activating one or more of the following:

a furnace control, a universal control, and an air handler control.

8. A controller configured for use in a climate control system, the controller comprising:

a power stealing circuit configured to be connectible with a control of the climate control system and configured for stealing power from a power source via a signal through the control, without using a common (C) wire from the power source and an RC/RH line where power is drawn when a relay switch in the controller is opened/closed;

an overcurrent limiting circuit configured to limit a first portion of the signal to prevent a false call for operation of the control, the overcurrent limiting circuit further configured not to limit a second portion of the signal to prevent a false call, where the control is configured to recognize only the first portion as determinative of whether the signal is a call for operation; and

a call generator configured to provide a call for operation of the control, the call including a signal portion configured to be unrecognized by the control as determinative of whether the signal is a call for operation and to provide a voltage for driving power stealing by the power stealing circuit;

wherein the power stealing circuit is configured to steal power via a call signal path.

9. A method performed by a controller in a climate control system, the method comprising:

configuring and sending a signal having first and second portions to a control of the climate control system such that only the first portion is determinative of whether the signal is a call for operation of the control;

limiting the first portion to prevent a false call for operation of the control; and

stealing power during at least the second portion, without using a common (C) wire from power source and an RC/RH line where power is drawn when a relay switch in the controller is opened/closed;

wherein the first portion is a positive portion of the signal and the second portion is a negative portion of the signal.

10. The method of claim 9, wherein the controller comprises a thermostat.

11. The method of claim 9, wherein the control is one or more of the following:

a furnace control, a universal control, and an air handler control.

12. The method of claim 9, further comprising:

receiving a power signal from a power source of the climate control system; and

configuring the signal to the control with an amplitude different from an amplitude of the signal from the power source.

13. The method of claim 9, wherein power is stolen during both the positive and negative portions.

14. A method performed by a controller in a climate control system, the method comprising:

configuring and sending a signal having first and second portions to a control of the climate control system such that only the first portion is determinative of whether the signal is a call for operation of the control;

limiting the first portion to prevent a false call for operation of the control;

stealing power during at least the second portion, without using a common (C) wire from power source and an RC/RH line where power is drawn when a relay switch in the controller is opened/closed; and

generating a call for operation of the control, the call including a signal portion configured to be unrecognized by the control as determinative of whether the signal is a call for operation and to provide a voltage for driving power stealing.

15. The method of claim 14, wherein the first portion is a positive portion of the signal and the second portion is a negative portion of the signal.

16. A controller configured for use in a climate control system, the controller comprising:

a power stealing circuit configured to be connectible with a control of the climate control system and configured for stealing power via a signal from a power source through the control, without using a common (C) wire from power source and an RC/RH line where power is drawn when a relay switch in the controller is opened/closed; and

an overcurrent limiting circuit configured to limit only a positive portion of the signal to prevent a false call for operation of the control, where only the positive portion is determinative of whether the control recognizes the signal as a call for operation.

17. The controller of claim 16, further configured to use a voltage across a dropping resistor of the control to drive the power stealing circuit.

18. The controller of claim 16, wherein the controller comprises a thermostat.

19. The controller of claim 16, further comprising a call generator configured to provide a call for operation of the control, the call including a signal portion configured to be filtered out by the control.

20. The controller of claim 19, wherein the call generator comprises a switching device including one or more of the following:

a relay, a triac, a thyristor, a transistor, a diode, a diode in series with a relay, a resistor in series with a relay, a voltage divider, and a MOSFET.