DEVICE FOR DETECTING A LOAD TYPE

• US 20130187631A1
• Filed: 01/24/2013
• Published: 07/25/2013
• Est. Priority Date: 01/25/2012
• Status: Active Grant

• Current Assignee: Snap One LLC (Resideo Technologies, Inc.)
• Original Assignee: Control4 Corporation (Resideo Technologies, Inc.)
• Inventors: Russell, James K., Bytheway, David Lynn, Schonle, William Richard
• Granted Patent: US 9,279,835 B2
• Time in Patent Office: Days
• US Class Current: 324/76.77
• CPC Class Codes: G01R 19/175 Indicating the instants of passage of current or voltage through a given value, e.g. passage through zero
• CPC Class Codes: G01R 19/2506 Arrangements for conditioning or analysing measured signals, e.g. for indicating peak values G01R19/003 takes precedence; Details concerning sampling, digitizing or waveform capturing displaying waveforms G01R13/00; analog sampling G01R19/0053
• CPC Class Codes: H02M 1/081 wherein the phase of the control voltage is adjustable with reference to the AC source

Abstract

A method for detecting a load type is described. The method includes placing an electronic device in a forward phase mode. The method also includes operating a load at a maximum allowable level. The method additionally includes capturing a voltage waveform. The method further includes capturing a current waveform. The method also includes obtaining a voltage zero-cross based on the voltage waveform. The method additionally includes obtaining a current zero-cross based on the current waveform. The method further includes determining the load type based on the voltage zero-cross and the current zero-cross.

Claims

1. A method for detecting a load type, comprising:

placing an electronic device in a forward phase mode;

operating a load at a maximum allowable level;

capturing a voltage waveform;

capturing a current waveform;

obtaining a voltage zero-cross based on the voltage waveform;

obtaining a current zero-cross based on the current waveform; and

determining a load type based on the voltage zero-cross and the current zero-cross.

2. The method of claim 1, wherein if the current zero-cross is less than the voltage zero-cross, then the load type is capacitive.

3. The method of claim 1, wherein if the voltage zero-cross is less than the current zero-cross, then the load type is inductive.

4. The method of claim 1, wherein if the voltage zero-cross equals the current zero-cross, then the method further comprises determining whether the electronic device is in a switch leg mode.

5. The method of claim 4, wherein if the electronic device is not in a switch leg mode, then the load type is resistive.

6. The method of claim 4, wherein if the electronic device is in a switch leg mode, the method further comprises determining whether a slope of the current waveform at the voltage zero-cross is greater than a threshold, wherein if the slope is greater than the threshold, then the load type is inductive, and wherein if the slope is less than the threshold, then the load type is resistive.

7. The method of claim 1, further comprising determining whether to drive the load connected to the electronic device in a forward phase mode or a reverse phase mode based on the load type.

8. The method of claim 7, wherein if the load type is inductive, then the load is driven in the forward phase mode, and wherein if the load type is capacitive, then the load is driven in the reverse phase mode.

9. An electronic device for detecting a load type, comprising:

a voltage sensor module, wherein the voltage sensor module captures a voltage waveform;

a current sensor module, wherein the current sensor module captures a current waveform;

a computing module coupled to the voltage sensor module and to the current sensor module, wherein the computing module;

places the electronic device in a forward phase mode;

operates a load at a maximum allowable level;

obtains a voltage zero-cross based on the voltage waveform;

obtains a current zero-cross based on the current waveform; and

determines a load type based on the voltage zero-cross and the current zero-cross.

10. The electronic device of claim 9, wherein if the current zero-cross is less than the voltage zero-cross, then the load type is capacitive.

11. The electronic device of claim 9, wherein if the voltage zero-cross is less than the current zero-cross, then the load type is inductive.

12. The electronic device of claim 9, wherein if the voltage zero-cross equals the current zero-cross, then the computing module determines whether the electronic device is in a switch leg mode.

13. The electronic device of claim 12, wherein if the electronic device is not in a switch leg mode, then the load type is resistive.

14. The electronic device of claim 12, wherein if the electronic device is in a switch leg mode, the computing module determines whether a slope of the current waveform at the voltage zero-cross is greater than a threshold, wherein if the slope is greater than the threshold, then the load type is inductive, and wherein if the slope is less than the threshold, then the load type is resistive.

15. The electronic device of claim 9, further comprising the computing module determining whether to drive the load connected to the electronic device in a forward phase mode or a reverse phase mode based on the load type.

16. The electronic device of claim 15, wherein if the load type is inductive, then the load is driven in the forward phase mode, and wherein if the load type is capacitive, then the load is driven in the reverse phase mode.

17. A computer-readable medium comprising executable instructions for:

placing an electronic device in a forward phase mode;

operating a load at a maximum allowable level;

capturing a voltage waveform;

capturing a current waveform;

obtaining a voltage zero-cross based on the voltage waveform;

obtaining a current zero-cross based on the current waveform; and

determining a load type based on the voltage zero-cross and the current zero-cross.

18. The computer-readable medium of claim 17, wherein if the current zero-cross is less than the voltage zero-cross, then the load type is capacitive, and wherein if the voltage zero-cross is less than the current zero-cross, then the load type is inductive.

19. The computer-readable medium of claim 17, wherein if the voltage zero-cross equals the current zero-cross, then the instructions are further executable for determining whether the electronic device is in a switch leg mode, wherein if the electronic device is not in a switch leg mode, then the load type is resistive.

20. The computer-readable medium of claim 19, wherein if the electronic device is in a switch leg mode, the instructions are further executable for determining whether a slope of the current waveform at the voltage zero-cross is greater than a threshold, wherein if the slope is greater than the threshold, then the load type is inductive, and wherein if the slope is less than the threshold, then the load type is resistive.