Method and Circuit for Determining Faults in Appliances

Patent metadata

Field	Value
Publication number	US-2016377673-A1
Application number	US-201315102948-A
Country	US
Kind code	A1
Filing date	Dec 9, 2013
Priority date	Dec 9, 2013
Publication date	Dec 29, 2016
Grant date	—

Abstract

A washing and/or drying appliance ( 100 ) is proposed. The washing and/or drying appliance ( 100 ) has a circuit system ( 200 ) comprising: an electric load ( 205 ) adapted to be energized by electrical coupling between first (T L ) and second (T N ) supply terminals of an electric power supply; first (SW L ) and second (SW N2 ) switching elements operable between respective closed/opened states for coupling/decoupling the first (T L ) and second (T N ) power supply terminals to/from first (T 1 ) and second (T 2,205 ) load terminals of the electric load ( 205 ); a control unit ( 215 ) for operating the first (SW L ) and second (SW N1 ,SW N2 ) switching elements, and a conditioning arrangement (D 1 ,220 1 ,R 1A -R 1C ). The conditioning arrangement (D 1 ,220 1 ,R 1A -R 1C ) has a unidirectional signal flow element (D 1 ) coupled between the first supply terminal (T L ) for receiving a supply signal (V SUPPLY ) and the second load terminal (T 2,205 ), and an impedance arrangement ( 220 I,RIA-RIC) coupled between the first load terminal (T 1 ) and the control unit ( 215 ). With the first (SW L ) and second (SW N2 ) switching elements in the opened-states the first supply terminal (T L ), the unidirectional signal flow element (Di), the electric load ( 205 ) and the impedance arrangement ( 220 1 ,R 1A -R 1C ) define a conductive path providing a check signal (S 1 ) to the control unit ( 215 ), the control unit ( 215 ) being configured for determining a fault in the circuit system ( 200 ) based on the check signal (S 1 ).

First claim

1 . Washing and/or drying appliance ( 100 ) having a circuit system ( 200 ) comprising:
an electric load ( 205 ) adapted to be energized by electrical coupling between first (T L ) and second (T N ) supply terminals of an electric power supply, first (SW L ) and second (SW N2 ) switching elements operable between respective closed/opened states for coupling/decoupling the first (T L ) and second (T N ) power supply terminals to/from first (T 1 ) and second (T 2,205 ) load terminals of the electric load ( 205 ), a control unit ( 215 ) for operating the first (SW L ) and second (SW N1 ,SW N2 ) switching elements, and a conditioning arrangement (D 1 , 220 1 ,R 1A -R 1C ) having
a unidirectional signal flow element (D 1 ) coupled between the first supply terminal (T L ) for receiving a supply signal (V SUPPLY ) and the second load terminal (T 2,205 ), and
an impedance arrangement ( 220 1 ,R 1A -R 1C ) coupled between the first load terminal (T 1 ) and the control unit ( 215 ), wherein, with the first (SW L ) and second (SW N2 ) switching elements in the opened-states the first supply terminal (T L ), the unidirectional signal flow element (D 1 ), the electric load ( 205 ) and the impedance arrangement ( 220 1 ,R 1A -R 1C ) define a conductive path providing a check signal (S 1 ) to the control unit ( 215 ),
and wherein the control unit ( 215 ) is configured for determining a fault in the circuit system ( 200 ) based on the check signal (S 1 ).

2 . Appliance ( 100 ) according to claim 1 , wherein the impedance arrangement ( 220 1 ,R 1A -R 1C ) is a voltage divider, so that the check signal (S 1 ) is scaled, with respect to the supply signal (V SUPPLY ), by a scaling factor (SF 1 ) of the voltage divider.

3 . Appliance ( 100 ) according to claim 1 or 2 , wherein the impedance arrangement ( 220 1 ,R 1A -R 1C ) is powered between a reference voltage (GND) and an operative voltage (V CC ), so that the check signal (S 1 ) is also shifted, with respect to the supply signal (V SUPPLY ), by a shifting voltage (SV) depending on said operative (V CC ) and reference (GND) voltages.

4 . Appliance ( 100 ) according to claim 3 , wherein the control unit ( 215 ) is powered between said operative (V CC ) and reference (GND) voltages so that the check signal (S 1 ) falls between an operation swing of the control unit ( 215 ).

5 . Appliance ( 100 ) according to any of the preceding claims, wherein the first switching element (SW L ) is a door switch, and wherein in the closed-state the door switch allows a mechanical lock of an appliance door ( 120 ) for preventing access to a treatment chamber ( 110 , 115 ) of the appliance ( 100 ).

6 . Appliance ( 100 ) according to any of the preceding claims, wherein
in absence of faults in the circuit system ( 200 ) the check signal (S 1 ) has a predetermined trend (S 1,EXP ) deriving from supply signal (V SUPPLY ) passage through said conductive path, a fault in the circuit system ( 200 ) affecting the conductive path causing the trend of the check signal (S 1 ) to mismatch said predetermined trend (S 1,EXP ), and wherein the control unit ( 215 ) is configured for determining, with the first (SW L ) and second (SW N2 ) switching elements in the opened-states, a fault in the circuit system ( 200 ) based on a mismatch between the trend of the check signal (S 1 ) and the respective predetermined trend (S 1,EXP ).

7 . Appliance ( 100 ) according to claim 6 ,
wherein the supply signal (V SUPPLY ) has an alternating full-wave periodic waveform, and wherein with the first (SW L ) and second (SW N2 ) switching elements in the opened-states:
the predetermined trend (S 1,EXP ) of the check signal (S 1 ) has a half-wave periodic waveform,
the control unit ( 215 ) is configured for determining a leakage between the electric load ( 205 ) and the first supply terminal (T L ) when the actual trend of the check signal (S 1 ) takes the full-wave periodic waveform.

8 . Appliance ( 100 ) according to claim 6 or 7 , wherein
with the first (SW L ) and second (SW N2 ) switching elements in the opened-states:
the predetermined trend (S 1,EXP ) of the check signal (S 1 ) has a predetermined peak value depending on sizing of the impedance arrangement ( 220 1 ,R 1A -R 1C ),
the control unit ( 215 ) is configured for determining a leakage between the electric load ( 205 ) and the second supply terminal (T N ) when the actual trend of the check signal (S 1 ) takes the half-wave periodic waveform with a peak value lower than said predetermined peak value by a predefined threshold amount.

9 . Appliance ( 100 ) according to any claim from 6 to 8 , further comprising a first further conditioning arrangement ( 220 2 ,R 2A -R 2B ,D 2 ) for providing a first further check signal (S 2 ),
and wherein with the first (SW L ) and second (SW N2 ) switching elements in the opened-states:
the predetermined trend (S 1,EXP ) of the check signal (S 1 ) has a shifting voltage (SV) given by first impedance arrangement ( 220 1 ,R 1A -R 1C ) powering, and the predetermined trend (S 2,EXP ) of the first further check signal (S 2 ) has the half-wave periodic waveform according to supply signal (V SUPPLY ) passage across the unidirectional signal flow element (D 1 ) and the first further conditioning arrangement ( 220 2 ,R 2A -R 2B ,D 2 ),
the control unit ( 215 ) is configured for determining a non-conductivity of the electric load ( 205 ) when the actual trend of the check signal (S 1 ) takes a constant trend at said shifting voltage (SV) and the actual trend of the first further check signal (S 2 ) matches the respective predetermined trend (S 2,EXP ).

10 . Appliance ( 100 ) according to claim 9 , wherein with the first (SW L ) and second (SW N2 ) switching elements in the off-states:
the control unit ( 215 ) is configured for determining an unwanted on-state of the second switching element (SW N2 ) when the actual trend of the check signal (S 1 ) takes the constant trend at said shifting voltage (SV) and the actual trend of the first further check signal (S 2 ) takes a constant trend at the reference voltage (GND).

11 . Appliance ( 100 ) according to claim 9 or 10 , further comprising a further electric load ( 210 ) between the first load terminal (T 1 ) and a third load terminal (T 2,210 ),
a third switching element (SW N1 ) operable for being switched to the second load terminal (T 2,205 ) or to the third load terminal (T 2,210 ), the closed/opened state of the second switching element (SW N2 ) allowing coupling/decoupling thereof to/from the third switching element (SW N2 ), and
a second further conditioning arrangement ( 220 3 ,R 3A -R 3B ) for providing a second further check signal (S 3 ),
wherein with the first (SW L ) and second (SW N2 ) switching elements in the off-states:
the predetermined trend (S 3,EXP ) of the second further check signal (S 3 ) has the half-wave periodic waveform deriving from passage of the supply signal (V SUPPLY ) across unidirectional signal flow element (D 1 ) and the second further conditioning arrangement ( 220 3 ,R 3A -R 3B ,D 3 ),
the control unit ( 215 ) is configured for determining a non-conductivity of the further electric load ( 210 ) when the actual trend of check signal (S 1 ) matches the respective predetermined trend (S 1,EXP ), and the actual trend of the second further check signal (S 3 ) takes the constant trend at the reference voltage (GND).

12 . Appliance ( 100 ) according to claim 11 , wherein, the first further ( 220 2 ,R 2A -R 2B ,D 2 ) and second further ( 220 3 ,R 3A -R 3B ,D 3 ) conditioning arrangements comprise first further (D 2 ) and second further (D 3 ) unidirectional signa

Assignees

• Electrolux Appliances AB

Inventors

• Cecco Alessandro
• Driussi Paolo

Classifications

• A47L2501/26

  Indication or alarm to the controlling device or to the user · CPC title

• A47L2401/30

  Variation of electrical, magnetical or optical quantities · CPC title

• A47L15/0049

  Detection or prevention of malfunction, including accident prevention (arrangements to prevent clogging of filters A47L15/4208; safety arrangements for preventing water damage A47L15/421) · CPC title

• D06F2105/58

  Indications or alarms to the control system or to the user · CPC title

• D06F58/50

  Responding to irregular working conditions, e.g. malfunctioning of blowers · CPC title