Method and circuit for determining dispersion of electric power towards ground in electric appliances

Patent metadata

Field	Value
Publication number	US-9817052-B2
Application number	US-201414780350-A
Country	US
Kind code	B2
Filing date	Mar 25, 2014
Priority date	Mar 28, 2013
Publication date	Nov 14, 2017
Grant date	Nov 14, 2017

Abstract

An electric appliance ( 100 ) is disclosed. The electric appliance has an electric load ( 205 ), and a driving element ( 215 ) for selectively energizing/de-energizing the electric load ( 205 ). The driving element ( 215 ) has a first driving terminal (A 1 ) coupled to a first load terminal (T 1 ) of the electric load, a second driving terminal (A 2 ) coupled to a first power supply terminal (T N ), and a control terminal (G) for switching on/off the driving element ( 215 ) thereby allowing said selective energization/de-energization, respectively. The electric appliance also has a switching element ( 230 ) for selectively coupling a second power supply terminal (T L ) to a second load terminal (T 2 ) of the electric load ( 205 ). The electric appliance ( 100 ) further has a detection arrangement ( 210,220 ) configured for detecting a first electrical quantity (V A1 ) at the first driving terminal (A 1 ), and at least one between a second electrical quantity (V T2,CL ,V T2,OP ) at the second load terminal (T 2 ) and a power supply electrical quantity (V MAINS ) at the second power supply terminal (T L ). The detection arrangement ( 210,220 ) has a coupling element ( 220 ) coupling the first driving terminal (A 1 ) to the second load terminal (T 2 ), and a control unit ( 210 ) coupled to the first driving terminal (A 1 ), and to at least one between the second load terminal (T 2 ) and the second power supply terminal (T L ). The control unit ( 210 ) is further configured for determining dispersion of electric power towards ground in the electric load ( 205 ) according to the detected electrical quantities.

First claim

The invention claimed is:

1. An electric appliance comprising:
an electric load;
a driving element for selectively energizing and de-energizing the electric load, the driving element having a first driving terminal (A 1 ) coupled to a first load terminal (T 1 ) of the electric load, a second driving terminal (A 2 ) coupled to a first power supply terminal (T N ), and a control terminal (G) for switching on and off the driving element to energize and de-energize the electric load, respectively;
a switching element for selectively coupling a second power supply terminal (T L ) to a second load terminal (T 2 ) of the electric load;
a coupling element coupling the first driving terminal (A 1 ) to the second load terminal (T 2 ); and
a control unit coupled to the first driving terminal (A 1 ), and to at least one of the second load terminal (T 2 ) and the second power supply terminal (T L ), the control unit being configured for:
determining a first value of a first electrical quantity (V A1 ) at the first driving terminal (A 1 );
determining a second value of a second electrical quantity (V T2,CL , V T2,OP , V MAINS ) at one of the second load terminal (T 2 ) and the second power supply terminal (T L ); and
determining, based on the first value of the first electrical quantity (V A1 ) and the second value of a second electrical quantity (V T2,CL , V T2,OP , V MAINS ), that there is dispersion of electric power towards ground in the electric load.

2. The electric appliance according to claim 1 , wherein the control unit is configured for:
comparing the first value of the first electrical quantity (V A1 ) to the second value of the second electrical quantity (V 12,CL ,V T2,OP , V MAINS ), and
determining that there is dispersion of electric power towards ground in the electric load according to a result of the comparing.

3. The electric appliance according to claim 2 ,
wherein the determining the first value of the first electrical quantity (V A1 ) at the first driving terminal (A 1 ) comprises extracting a first pick value (V A1 ) among values of electrical quantities at the first driving terminal (A 1 ),
wherein the determining the second value of the second electrical quantity (V T2,CL , V T2,OP , V MAINS ) comprises extracting a second pick value (V T2,CL ,V T2,OP , V MAINS ) among values of electrical quantities at one of the second load terminal (T 2 ) and the second power supply terminal (T L ), and
wherein the comparing comprises comparing the first pick value (V A1 ) to the second pick value (V T2,CL , V T2,OP , V MAINS ).

4. The electric appliance according to claim 3 ,
wherein the switching element is operable to allow and prevent electrical coupling between the second load terminal (T 2 ) and the second power supply terminal (T L ) according to a closed configuration and an opened configuration, respectively, of an appliance door,
wherein the extracting the second pick value (V 12,CL , V T2,OP ) comprises taking a first peak value (V T2,CL ) indicative of the closed configuration, or a second peak value (V T2,OP ) indicative of the opened configuration.

5. The electric appliance according to claim 4 , wherein in the closed configuration:
said comparing comprises:
comparing the first pick value (V A1 ) to the first peak value (V T2,CL ), and

said determining comprises:
determining that there is dispersion of electric power towards ground in the electric load if the first pick value (V A1 ) exceeds the first peak value (V T2,CL ) at least by a first threshold value (V TH1 ).

6. The electric appliance according to claim 5 , wherein in the opened configuration:
said comparing comprises:
comparing the first pick value (V A1 ) to the second peak value (V T2,OP ); and
comparing the first pick value (V A1 ) to a third peak value (V MAINS ) of electrical quantities (V MAINS ) at the second power supply terminal (T L ), and

said determining comprises:
determining that there is dispersion of electric power towards ground in the electric load if the first pick value (V A1 ) exceeds the second peak value (V T2,OP ) at least by a second threshold value (V TH2 ) and exceeds the third peak value (V MAINS ) at least by a third threshold value (V TH3 ).

7. The electric appliance according to claim 6 , wherein
in the closed configuration, the second power supply terminal (T L ) and the second load terminal (T 2 ) are substantially short-circuited to each other so that the first peak value (V T2,CL ) substantially equals the third peak value (V MAINS ), and
in the opened configuration, the second power supply terminal (T L ) and the second load terminal (T 2 ) are substantially isolated from each other so that the second peak value (V T2,OP ) is lower than the third peak value (V MAINS ).

8. The electric appliance according to claim 4 , wherein in the opened configuration:
said comparing comprises:
comparing the first pick value (V A1 ) to the second peak value (V T2,OP );and
comparing the first pick value (V A1 ) to a third peak value (V MAINS ) of electrical quantities (V MAINS ) at the second power supply terminal (T L ), and

said determining comprises:
determining that there is dispersion of electric power towards ground in the electric load if the first pick value (V A1 ) exceeds the second peak value (V T2,OP ) at least by a second threshold value (V TH2 ) and exceeds the third peak value (V MAINS ) at least by a third threshold value (V TH3 ).

9. The electric appliance according to claim 8 , wherein:
in the closed configuration, the second power supply terminal (T L ) and the second load terminal (T 2 ) are substantially short-circuited to each other so that the first peak value (V T2,CL ) substantially equals the third peak value (V MAINS ), and
in the opened configuration, the second power supply terminal (T L ) and the second load terminal (T 2 ) are substantially isolated from each other so that the second peak value (V T2,OP ) is lower than the third peak value (V MAINS ).

10. The electric appliance according to claim 3 , wherein
said comparing comprises:
comparing the first pick value (V A1 ) to the second pick value (V MAINS ) among the electrical quantities at the second power supply terminal (T L ), and

said determining comprises:
determining that there is dispersion of electric power towards ground in the electric load if the first pick value (V A1 ) exceeds the second pick value (V MAINS ) at least by a threshold voltage (V TH4 ).

11. The electric appliance according to claim 1 , wherein the driving element comprises a triac.

12. The electric appliance according to claim 1 , wherein the electric load comprises an electric motor.

13. The electric appliance according to claim 1 , wherein the electric appliance comprises a washing machine, a drying machine, or a washing/drying machine.

14. The electric appliance according to claim 11 , wherein the electric appliance comprises a rotating drum adapted to house laundry to be washed and/or dried, and wherein the electric load comprises an electric motor for drum rotation.

15. The electric appliance according to claim 1 ,
wherein the control unit is directly coupled to the first driving terminal (A 1 ) such that a voltage at the first driving terminal (A 1 ) substantially equals a voltage at a first input of the control unit, and
wherein the control unit is directly coupled to at least one of the second load terminal (T 2 ) and the second power supply terminal (TL) such that a voltage at the second load terminal (T 2 ) substantially equals a voltage at a second input of the control unit or a voltage at the

Assignees

• Electrolux Appliances AB

Inventors

• Cecco Alessandro
• Driussi Paolo

Classifications

• G05B9/02 Primary

  electric · CPC title

• H02H3/162

  for AC systems · CPC title

• G01R31/2825

  in household appliances or professional audio/video equipment (testing LAN's H04L43/50; testing TV systems H04N17/00; testing loudspeakers H04R29/00) · CPC title

• D06F37/42

  Safety arrangements, e.g. for stopping rotation of the receptacle upon opening of the casing door · CPC title

• D06F37/304

  Arrangements or adaptations of electric motors · CPC title