Electrolux Home Products Corporation N.v.

Marco Lorenzi

Paolo Driussi

Alessandro Cecco

Hubert Dorigo

A washing and/or drying appliance includes a heating circuit () for heating a washing liquid and/or a drying air flow. The heating circuit is connected to voltage distribution lines () distributing power inside the appliance and includes at least one heating resistor () in series to switch means () controlled by an appliance control unit () for selectively energizing the heating resistor when required. The switch means of the heating circuit includes first and second switches () in series to the heating resistor, the heating resistor being interposed between the first and second switch. A monitoring circuit arrangement is associated with the heating circuit. The monitoring circuit arrangement includes a resistive network including a first resistor (R) connected to the heating circuit so as to be bypassed when the first switch is closed, the heating resistor, and a second resistor (R) connected to the heating circuit so as to be bypassed when the second switch is closed. The monitoring circuit arrangement further includes a current sensor () arranged to measure a current flowing through the resistive network and to feed an indication of the measured current to the control unit. The monitoring unit is configured for assessing possible faults of the heating circuit based on the indication of the measured current.

Heating circuit with monitoring arrangement for a household appliance

A household appliance has a heating circuit () for heating a fluid including a heating element () that can be selectively energized () to determine the heating of the fluid, and a monitoring unit () for monitoring the operation of the heating circuit. The monitoring unit () is configured to monitor at least one electrical potential internal to the heating circuit (). The at least one electric potential internal to the heating circuit () is at least one among: an internal electric potential detected at a first terminal () of the heating element () connected to an on/off switch () of the heating circuit (); an internal electric potential detected at a second terminal () of the heating element () connected to a main switch () of the appliance or to a safety switch provided for switching the heating circuit off in case of malfunction of the on/off switch (). The monitoring unit () is further configured for: detecting a value of the voltage of the electricity distribution network; and calculating, starting from the detected value of the voltage of the electricity distribution network, first and a second reference electric potentials, comparing the at least one detected internal electric potential with the first and second reference electric potentials; recognizing a state of good operation or malfunction of the heating circuit () in case the at least one detected internal electric potential does not fall within a range of values between the first and second reference electric potentials.

Monitoring faults in the heating circuit of an appliance

A washing and/or drying appliance includes a heating circuit () for heating a washing liquid and/or a drying air flow, connected to voltage distribution lines () distributing power inside the appliance. The heating circuit includes at least one heating resistor () in series to switch means () controlled by an appliance control unit () for selectively energizing the heating resistor when required. The switch means of the heating circuit includes a first and a second switch () in series to the heating resistor, the heating resistor being interposed between the first and second switches. A monitoring circuit arrangement is provided, which includes a first resistor (R) in shunt to the heating resistor and having a resistance substantially higher than that of the heating resistor, and a pull-up network connected between a first terminal () of the heating resistor and one of the voltage distribution lines. The control unit is configured for receiving a voltage corresponding to an electric potential at a second terminal () of the heating resistor.

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Porcia, Italy

Marco Lorenzi