WO2013098015A2

WO2013098015A2 - A household appliance protected from mains over voltage

Info

Publication number: WO2013098015A2
Application number: PCT/EP2012/073637
Authority: WO
Inventors: Ufuk Levan Yakut; Baris Ocak; Ovunc Doruk Izgen
Original assignee: Arcelik Anonim Sirketi
Priority date: 2011-12-26
Filing date: 2012-11-26
Publication date: 2013-07-04
Also published as: WO2013098015A3; EP2798722A2

Abstract

The present invention relates to a household appliance (1) comprising a power control circuitry (2), connected to the AC mains voltage, that operates the components (B) like motor, compressor, fan, heater, LED and display with suitable voltages, a microcontroller (3) that controls the switching elements (11) like relay, triac which drive the components (B), a power source unit (10) that provides the microcontroller (3) and the switching elements (11) to be fed, an energy outage detection circuit (4) that detects whether or not AC mains voltage exists, that provides the microcontroller (3) and the switching elements (11) to be kept energized in short term mains electricity outages, providing the power control circuitry (2) to be kept in active state in order to resume the implemented program when the mains energy comes back on and an energy storage unit (5) that provides the microcontroller (3) and the switching elements (11) to be kept energized in energy outages.

Description

A HOUSEHOLD APPLIANCE PROTECTED FROM MAINS OVER VOLTAGE

The present invention relates to a household appliance wherein the power control circuitry operating the components like the motor, the compressor and the heater is protected from mains over voltage.

Household appliances, for example refrigerators, washers like laundry washer or dishwasher and cooking devices operate with a certain operating voltage by receiving the required electrical energy from the mains Voltage values other than the specified standard values are observed due to various breakdowns that happen in the mains. The household appliances are adversely affected by the voltage fluctuations in the mains since they are generally connected to the mains during their expected lives. In most cases, protective devices and/or methods are used against the said high/low voltage circumstances on the electronic control systems of the household appliances. The energy required for functioning of the electronic control systems used in household appliances is supplied by the power control circuitry through the mains electricity. The power control circuitry produces the rectified and decreased voltage and/or the current necessary for itself and the remainder of the electronic control system. In over voltage situations of the mains, operation of the above mentioned power control circuitry is stopped and it is protected from probable damages. The power control circuitry is also stopped in mains voltage outage and the electronic control system provides the power required from the capacitors. However, in most situations, the amount of energy that can be stored by the capacitors is not at a level necessary for allowing the system to operate for a sufficiently long period of time. Therefore, if the said over voltage situation lasts longer than a critical time period, the electronic system is deprived of the energy required for sustaining its function since the power control circuitry also stops operation during this time period. The power control circuitry, that starts to operate after the mains over voltage situation is eliminated, produces output again and activates the entire electronic control system; however, if a program was being implemented in the household appliance before occurrence of over voltage situation (like washing of laundry for washing machine, cooking food for the oven etc), in most cases, the program cannot be continued without user intervention due safety and/or product constraints after reactivation or the information about the program that is operated can be lost. Requiring user intervention for the household appliance to continue operation or losing the program information of the ongoing program is an unwanted situation in terms of consumer satisfaction. In household appliances, precautions are taken for the power control circuitry, left without energy while protecting itself from over voltage conditions, to continue operating with the energy storage components for the longest time period possible. For example, supercapacitors are used however, the cost of supercapacitors is quite high.

In the International Patent Application No. WO03065535, the voltage at mains inlet is detected by a voltage divider in the DC line, the voltage in the DC line is compared with a reference voltage value by means of a comparator. When over voltage is detected, a trigger signal is generated providing the earth leakage circuit breaker to operate. Consequently, over voltage protection is provided by deactivating the live (L) and neutral (N) wires of the DC power source.

In the International Patent Application No. WO2004068686, a power control circuitry that precisely regulates the excessive voltage and excessive temperature protection level is described. The switch mode power supply (SMPS) is controlled by detecting heat protection, excessive current and voltage protection by means of a Schottky barrier diode, LED and photo transistor.

The aim of the present invention is the realization of a household appliance that is protected from over voltage by low cost power control circuitry, supplying power to its components, is provided to be kept in active mode during this protection duration.

The household appliance like refrigerator, cooking device, washing machine or dishwasher, realized in order to attain the aim of the present invention, explicated in the first claim and the respective claims thereof, comprises a power control circuitry that operates the components like motor, compressor, fan heater and display with suitable voltages, an energy outage detection circuit that detects whether or not mains voltage exists, an energy storage unit like capacitor that provides the microcontroller and the electronic switching elements which operate the components during energy outages to keep energized and an over voltage detection circuit that detects mains voltage higher than a specified value like 220 - 230, stops operation of the power source unit upon detection of mains over voltage and at the same time provides the microcontroller to be informed about the over voltage situation by sending signal to the microcontroller. The microcontroller, upon detection of over voltage situation, provides the power control circuitry to be fed from the storage unit for some more time and to stay active so that the program being implemented at the household appliance is resumed without user intervention when the over voltage state is eliminated. During this time period, the microcontroller is provided to store the program that is being implemented in its memory.

In an embodiment of the present invention, the microcontroller, upon detection of over voltage situation, implements the actions performed in “short term energy outage” situation, for keeping the power control circuitry alive for some more time.

In another embodiment of the present invention, the household appliance comprises a first microcontroller outlet that connects the over voltage detection unit to the microcontroller and that delivers over voltage detection signal.

In another embodiment of the present invention, the household appliance comprises a second microcontroller outlet that delivers signal from the energy outage detection circuit to the microcontroller and a logic gate that joins the first microcontroller outlet and the second microcontroller outlet and delivers to the microcontroller as a single signal. The logic gate applies “AND” operation between the over voltage detection signal and energy outage detection signal and delivers to the microcontroller.

In another embodiment of the present invention, an outlet of the over voltage detection unit is connected to the switching elements that operates the components and cuts off the energy of the switching elements independently from the microcontroller when mains over voltage is detected.

In the household appliance of the present invention, the power control circuitry is provided to be kept active for some more time when mains over voltage is detected, and when over voltage situation is eliminated, the program being implemented in the household appliance is resumed without requiring user intervention. When mains over voltage occurs, the connection of the electronic switching elements with the mains voltage is rapidly cut off and protected against over voltage, furthermore the staying active duration of the power control circuitry is increased.

The household appliance realized in order to attain the aim of the present invention is illustrated in the attached figures, where:

Figure 1 – is the schematic view of a household appliance.

Figure 2 – is the schematic view of a household appliance in an embodiment of the present invention.

Figure 3 – is the schematic view of a household appliance in another embodiment of the present invention.

The elements illustrated in the figures are numbered as follows:

Household appliance
Power control circuitry
Microcontroller
Energy outage detection circuit
Energy storage unit
Over voltage detection circuit
First microcontroller outlet
Second microcontroller outlet
Logic gate
Power source unit
Switching element

The household appliance (1) comprises a power control circuitry (2), connected to the AC mains voltage, that operates the components (B) like the motor, compressor, fan, heater, LED and display with suitable voltages, one or more than one electronic switching element (11) like relay, triac operating the components (B), a microcontroller (3) that controls the switching elements (11), a power source unit (10), preferably SMPS (Switched Mode Power Supply), having a rectifier (R) that converts AC mains voltage into DC voltage and a DC-DC converter (D), providing the microcontroller (3) and the switching elements (11) to be fed by generating low value DC voltages (like 5V - 15V), an energy outage detection circuit (4) connected to AC mains voltage, generating square wave signals by monitoring zero crossings of the AC mains voltage and detecting whether or not mains voltage exists, keeping the microcontroller (3) and the switching elements (11) energized in short term (momentary) mains electricity outages, providing the microcontroller (3) to store the implemented program in its memory so that the program implemented in the household appliance (1) is resumed when the mains energy comes back on and to perform actions of changing the switching elements (11) to deenergized/off mode (for example blackening of the display) in order to prolong the staying active duration of the power control circuitry (2) and an energy storage unit (5) like capacitor, that provides the microcontroller (3) to be fed and provides the switching elements (11) to be kept energized (to be ready for turning off) in short term energy outages.

The household appliance (1) of the present invention comprises an over voltage detection circuit (6) that detects mains over voltage from the rectifier (R) outlet, stops the operation of the power source unit (10) upon detection of mains over voltage, sends signals to the microcontroller (3) and provides the microcontroller (3) to keep the power source unit (10) active until the over voltage situation is eliminated.

The microcontroller (3), upon detection of over voltage situation by the over voltage detection circuit (6), performs the actions carried out in “short term energy outage”, existing in its software like:

- storing the program being implemented in the memory and

-changing the switching elements (11) to deenergized/off mode in order to prolong the staying active duration of the power control circuitry (2).

There is a software in the microcontroller (3) that switches into active state in short term energy outages and provides the microcontroller (3) to keep the power control circuitry (2) active for some more time, for example a few hundred milliseconds more, in order to resume the program being implemented in the household appliance (1) when energy comes back on; and when over voltage is detected by the over voltage detection circuit (6) the microcontroller (3) is provided to perform the “same” actions as in the energy outage situation by delivering signal to the microcontroller (3). In the microcontroller (3), using separate software or making changes in the software is not required for performing the actions in order to prolong the staying active duration of the power control circuitry (2) in short term over voltage state or short term energy outage situation, the microcontroller (3) is provided to give the same response in both over voltage state and also the energy outage situation with the present software. When mains over voltage is detected, operation of the power source unit (10) is stopped by the over voltage detection circuit (6) and first of all the power control circuitry (2) is protected from over voltage. When mains over voltage is detected, the signal generated by the over voltage detection circuit (6) is delivered to both the power source unit (10) and the microcontroller (3) and the microcontroller (3) is provided to perform the actions performed when energy is cut off also in the over voltage situation. When any one of the “mains over voltage” or “mains energy absent” situations occur, the same warning is generated for the microcontroller (3) and the power control circuitry (2) is provided to remain active for the longest time possible (in milliseconds) by performing the same action.

In an embodiment of the present invention, the household appliance (1) comprises a first microcontroller outlet (7) that connects the over voltage detection circuit (6) to any one pin of the microcontroller (3), that delivers logic “1” or “0” signal or current/voltage in analogue level, and the microcontroller (3) decides whether or not over voltage situation exists by evaluating the signal/voltage delivered from the first microcontroller outlet (7) (Figure 1).

In another embodiment of the present invention, the household appliance (1) comprises a second microcontroller outlet (8) that delivers logic “1” or “0” signal or current/voltage in analogue level from the energy outage detection circuit (4) to the microcontroller (3) and a logic gate (9) that joins the first microcontroller outlet (7) and the second microcontroller outlet (8), delivers to the microcontroller (3) as a single signal (Figure 2). Thus, the microcontroller (3) detects the situations of mains over voltage and energy outage by means of a single pin and it is not required to use separate pin inlets for two different situations.

In this embodiment, the logic gate (9) performs the logic “AND” operation between the over voltage detection signal and the energy outage detection signal and delivers to the microcontroller (3). For example:

Mains over voltage = “0”

Normal mains voltage = “1”

Mains voltage absent = “0”

Mains voltage present = “1”

When evaluated with the above signals, if the mains over voltage is present (“0”), “0” signal is delivered to the microcontroller (3) even if the energy outage detection circuit (4) sends “1” or “0” signal. Similarly, in energy outage situation (“0”), even if the over voltage detection circuit (6) delivers “1” or “0” signal, “0” signal is delivered to the microcontroller (3). Consequently, the microcontroller (3) receives “0” signal in over voltage situation or energy outage situation and performs the same actions in both situations in order to prolong staying active duration of the power control circuitry (2).

In another embodiment of the present invention, one or more than one outlet of the over voltage detection circuit (6) is connected to the switching elements (11) and when mains over voltage is detected, the energy of the switching elements (11) is cut off directly, in terms of hardware, independently from the microcontroller (3) (Figure 3).

Upon detection of mains over voltage, one of the actions of prolonging active time of the power control circuitry (2), overtaken by the microprocessor (3), as explained before, is to end the driving/keeping energized the switching elements (11) like relay, triac. Some time passes between the over voltage detection circuit (6) producing output and the microcontroller (3) detecting this output and cutting off the energy of the switching elements (11). In this embodiment, in order to also recycle the energy consumed by the switching elements (11) during the time of keeping the power control circuitry (2) active, the energy of the switching elements (11) is cut off directly by the over voltage detection circuit (6) in terms of hardware, in a much shorter time period than the microcontroller (3) and the staying active duration of the power control circuitry (2) is prolonged. In mains over voltage situation, if the energy of the switching elements (11) is cut off by the microcontroller (3), staying active duration of the power control circuitry (2) is for example approximately 400 milliseconds, if the energy of the switching elements (11) is cut off directly by the over voltage detection circuit (6) then staying active duration of the power control circuitry (2) is increased to for example approximately 700 milliseconds.

In an embodiment of the present invention, the household appliance (1) is a refrigerator.

In another embodiment of the present invention, the household appliance (1) is a washing machine or laundry washer/dryer.

In another embodiment of the present invention, the household appliance (1) is a laundry dryer.

In another embodiment of the present invention, the household appliance (1) is a cooking device.

In another embodiment of the present invention, the household appliance (1) is a dishwasher.

In the household appliance (1) of the present invention, when the mains over voltage situation is detected by the over voltage detection circuit (6), the microcontroller (3) is also informed of the situation and the microcontroller (3) is provided to respond to mains over voltage situation with an action. The microcontroller (3) implements the actions of keeping the power control circuitry (2) active for some more time and the storing the ongoing program in the electricity outage situation also in the over voltage situation. As the result of this action, when operation of the household appliance (1) is stopped due to mains over voltage, it is provided to operate again and resume the ongoing program without user intervention when mains voltage returns to normal. The power control circuitry (2) is provided to be kept in active mode for a long time (in milliseconds) under over voltage conditions. Cost advantage is provided by the said increase in duration of staying active with comparison to conventional methods (like using a greater number of capacitors for storing energy) that can be utilized. When mains over voltage occurs, the connection of the switching elements (11), that drive the components (B) like the motor, compressor, fan, heater, display, is rapidly cut off with AC mains voltage and protected against over voltage.

It is to be understood that the present invention is not limited by the embodiments disclosed above and a person skilled in the art can easily introduce different embodiments. These should be considered within the scope of the protection postulated by the claims of the present invention.

Claims

A household appliance (1) comprising a power control circuitry (2) connected to AC mains voltage, that operates the components (B) like motor, compressor, fan, heater, LED and display with suitable voltages, a microcontroller (3) that controls the switching elements (11) like relay, triac driving the components (B), a power source unit (10) providing the microcontroller (3) and the switching elements (11) to be fed, an energy outage detection circuit (4) detecting whether or not mains voltage exists, in short term (momentary) mains electricity outages, providing the microcontroller (3) and the switching elements (11) to resume the implemented program when mains energy comes back on, and an energy storage unit (5) that provides the microcontroller (3) and the switching elements (11) to be kept energized in energy outages, characterized by an over voltage detection circuit (6) that detects mains over voltage, stops operation of the power source unit (10) upon detection of mains over voltage, delivers signals to the microcontroller (3) and provides the microcontroller (3) to keep the power control circuitry (2) in active mode until the over voltage situation is eliminated.
A household appliance (1) as in Claim 1, characterized by the microcontroller (3) that stores the implemented program in its memory and changes the switching elements (11) to deenergized/off mode when mains over voltage situation is detected by the over voltage detection circuit (6).
A household appliance (1) as in Claim 1 or 2, characterized by a first microcontroller outlet (7) that connects the over voltage detection circuit (6) to the microcontroller (3), and delivers logic “1” or “0” signal or current/voltage in analogue level.
A household appliance (1) as in Claim 3, characterized by a second microcontroller outlet (8) that delivers logic “1” or “0” signal or current/voltage in analogue level from the energy outage detection circuit (4) to the microcontroller (3) and a logic gate (9) that joins the first microcontroller outlet (7) and the second microcontroller outlet (8), delivering as a single signal to the microcontroller (3).
A household appliance (1) as in Claim 4, characterized by the logic gate (9) that applies logic “AND” operation between the over voltage detection signal and energy outage detection signal and delivers to the microcontroller (3).
A household appliance (1) as in any one of the above Claims, characterized by the over voltage detection circuit (6), one or more than one outlet of which is connected to the switching elements (11), that directly cuts off the energy of the switching elements (11), independently from the microcontroller (3) when mains over voltage is detected.
A household appliance (1) as in any one of the above claims characterized by being a refrigerator.
A household appliance (1) as in any one of the Claims 1 to 6, characterized by being a washing machine or laundry washer/dryer.
A household appliance (1) as in any one of the Claims 1 to 6, characterized by being a laundry dryer.
A household appliance (1) as in any one of the Claims 1 to 6, characterized by being a cooking device.
A household appliance (1) as in any one of the Claims 1 to 6, characterized by being a dishwasher.