DE102008039450A1 - Method for detecting operating condition of electrical appliance i.e. electrical heating device, and for disconnecting appliance in non-determined operating condition, involves disconnecting electrical appliance from supply voltage - Google Patents

Abstract

The method involves measuring current consumption of an electrical appliance i.e. electric heating device, in all determined operating conditions of the electrical appliance. The measured values of the current consumption of the electrical appliance for the determined operating conditions are stored. The electrical appliance is disconnected from a supply voltage when measured actual current consumption deviates away from the stored values of the current consumption of the electrical appliance over a preset tolerance value. An independent claim is also included for a device for connecting an electrical appliance.

Description

The The invention relates to a method for detecting the operating state an electrical appliance, in particular of electric heaters, and to unlock the electrical appliance in non-intended operating conditions.

method for detecting the operating state of an electrical appliance and for Activation of the electrical appliance in non-intended operating conditions known from the prior art. For example, the electrical appliance becomes a fuse element upstream, which unlocks the electrical device when the power consumption of the electrical appliance exceeds a predetermined value. These fuse elements serve to detect a short circuit in the electrical appliance and the electrical appliance in case of a short circuit. This is for example a continuing one damage of the electrical appliance or the emergence of a fire within the electrical device prevented. A disadvantage of these fuse elements is that the fuse element only when crossing the predetermined trip current the electrical appliance unlocks. Thus, you can such fuse elements no faulty operating conditions of the electrical appliance detect where the tripping current of the fuse element is not exceeded. However, you can also such faulty operating states of the electrical appliance, at which the tripping current of the fuse element is not exceeded becomes damaging of the electrical appliance or cause the creation of a fire within the electrical appliance.

One Another method for detecting the operating state of an electrical appliance and activation of the electrical appliance in non-intended operating conditions known from the electrical installation of buildings. In the electrical installation of buildings One or more circuits are formed, each one or several electrical appliances with supply the mains voltage. Each circuit is replaced by a hedged so-called automatic circuit breakers, wherein the circuit breaker when exceeded a predetermined maximum current value triggers and the entire circuit unlocked. The activation of the entire circuit has the advantage that is not damaged by a short circuit in an electrical appliance, an adjacent electrical appliance. However, the circuit breaker has the same disadvantages as the fuse element described above, which is connected directly upstream of an electrical appliance becomes.

Farther is from the field of electrical installation in buildings Residual current circuit breaker (RCCB) known, the electrical equipment and / or Circuits unlock in non-intended operating conditions. An RCCB compares the input current of a circuit with the output current of the circuit and turns on the circuit free when the output current is a predetermined value of different from the input current. The output current of the circuit differs, for example, from the input current of the circuit, if a live one Part of the circuit in contact with another conductive object comes, over drain the electricity can. This is z. As is the case when a person is a current-carrying Part touched within the circuit, because about this person a so-called Fault current drain to ground can.

advantageously, redeems Residual current circuit breaker at a fault current of 30 mA, because from a current of about 50 mA by the human body with health consequences is to be expected and these can thus be prevented. adversely at the RCCB is that only fault currents, the from the supervised Drain the circuit, lead to the activation of the relevant circuit. One RCCB can not short-circuit inside the circuit or increased power consumption an electrical appliance within the circuit.

Of the Invention is therefore the object of an improved method for detecting the operating state of an electrical appliance and activation of the electrical appliance to provide in non-intended operating conditions.

• – erstmaliges Messen der Stromaufnahme des Elektrogeräts in allen bestimmungsgemäßen Betriebszuständen des Elektrogeräts,
• – Speichern der gemessenen Werte der Stromaufnahme des Elektrogeräts für die bestimmungsgemäßen Betriebszustände,
• – Permanentes oder regelmäßiges Messen der aktuellen Stromaufnahme des Elektrogeräts im Betriebfall,
• – Vergleichen der gemessenen aktuellen Stromaufnahme des Elektrogeräts mit den gespeicherten Werten der Stromaufnahme des Elektrogeräts,
• – Freischalten des Elektrogeräts von der Versorgungsspannung, wenn der gemessene aktuelle Stromverbrauch von den gespeicherten Werten der Stromaufnahme des Elektrogeräts über einen vorgegebenen Toleranzwert hinweg abweicht.

The object is achieved by a method for detecting the operating state of an electrical appliance, in particular of electric heating appliances, and for activating the electrical appliance in operating states that are not determined, comprising the steps:

• Initial measurement of the current consumption of the electrical appliance in all intended operating states of the electrical appliance,
• Storing the measured values of the power consumption of the electrical appliance for the intended operating conditions,
• Permanent or regular measurement of the current current consumption of the electrical appliance during operation,
• Comparing the measured current current consumption of the electrical appliance with the stored values of the current consumption of the electrical appliance,
• - Disconnecting the electrical appliance from the supply voltage when the measured current power consumption deviates from the stored values of the current consumption of the electrical appliance over a predetermined tolerance value.

An electrical appliance can be one or more be have moody operating conditions, so for example, an electric heater, the states "heat" and "keep warm" include. According to the invention, the current consumption of the electrical appliance is measured for all intended operating states of the electrical appliance. The measured values of the current consumption of the electrical appliance for the intended operating conditions are stored.

in the Operating case of the electrical appliance is the current consumption by a permanent or regular measurement of the electrical appliance certainly. The measured current consumption of the electrical appliance is compared with the stored values of the power consumption of the electrical device for all intended operating conditions.

Should the current measured current consumption of the electrical appliance is not correspond to one of the stored power consumptions of the electrical appliance for the intended operating conditions, wherein according to the invention a predetermined Tolerance range taken into account becomes, becomes the electrical appliance released from the supply voltage.

The inventive method has opposite the known from the prior art method has the advantage that it's a change of the operating state of the electrical appliance can detect before it there is a short circuit inside the electrical appliance or a faulty current flows to the ground. For example, the inventive method can recognize when the current consumption of the electrical appliance by a defective component inside the electrical appliance changed. Such a defective component could to an increased Heat development inside the appliance and in the worst case lead to a fire.

Farther can the inventive method a cable break or a loose contact in the electrical appliance or the Supply line to the electrical appliance detect. If the method according to the invention detects a cable break or loose contact, the electrical device is unlocked to prevent further damage.

The inventive method allows to monitor the operational and technical condition of electrical appliances and an electrical appliance to turn off the power in the event of a defect before it becomes dangerous State.

In an embodiment the invention is the stored value of the current consumption of the electrical appliance for the intended operating condition adjusted with the measured current value of power consumption when no activation was made.

The Power consumption of electrical appliances can to change with time, for example due to the aging of the components used. This does not mean, however, that a dangerous condition arises, for example, could cause a fire. The inventive method fits such a change the current consumption of the electrical appliance in that the stored values of the power consumption of the electrical appliance for the various with intended operating conditions adapted to the current measured values of the current consumption for the operating states become. Will the electrical appliance unlocked, this adjustment is not made.

In a preferred embodiment The invention will be a list of at least the last three measured Values of current consumption of the electrical appliance for each intended operating condition of the electrical appliance stored, preferably a list of the last five measured values the current consumption of the electrical appliance, wherein in case of need the oldest one Measured value deleted becomes.

Next an adaptation to a temporal change of the current consumption of the Electrical appliance has this has the advantage that the process is also sensitive to fluctuations in the height the supply voltage adapts.

alternative To save a list, an average can be saved from the list Values of current consumption of the electrical appliance for the intended operating condition and the measured value of the current consumption of the electrical appliance for the operating state be formed and stored, the previous saved Value is deleted.

In a further embodiment The invention is in addition to the power consumption of the electrical appliance for the various also according to the intended operating conditions the duration of power consumption of the electrical appliance for the intended operating conditions measured and saved.

The measurement and storage of the duration of power consumption of the electrical appliance for the intended operating conditions has the advantage that the inventive method can detect when the electrical appliance remains in a normal operating condition, although it has to change to another intended operating condition. For example, the electric appliance should have the operating status "heat up" for a period of 5 minutes and then switch to the operating state "keep warm". Has the Device, for example, after a time of 6 min has not yet changed the operating state of "heat" in "keep warm", then the electrical device is enabled by the inventive method, since a designated operating condition is too long active, which can lead to a dangerous operating condition.

The most electrical appliances, especially electric heaters only over operated a well-defined period and not in continuous operation. Forgets the user of the electrical appliance after use this can also lead to a dangerous condition. Therefore, switch the inventive method according to one embodiment invention of the electrical appliance according to a given time free.

Preferably is the stored time duration of power consumption of the electrical device for the intended operating condition with the measured duration of the power consumption of the electrical appliance for the intended operating condition adapted, for example by saving a list of the last measured values or by storing an average value. Consequently can the process of the invention a change of the electrical appliance adjust, as already described above.

In a further embodiment the invention, the electrical device is exceeded when a predetermined maximum current consumption enabled, regardless of a deviation of the measured current consumption from the stored values of the current consumption of the electrical appliance. The specified maximum current consumption protects the electrical appliance against damage, that can arise as a result that, for example, during the first measurement already a short circuit in the electrical appliance available is, whereby the stored value of the current consumption for the operating state much would be too high. Upon reaching the predetermined maximum power consumption is the Electrical appliance unlocked, so that independent from the result of the first measurement, the device is protected from damage.

In a preferred embodiment be several electrical appliances simultaneously monitored by the method according to the invention.

• – wenigstens einen Netzanschluss,
• – wenigstens einen Lastanschluss,
• – wenigstens eine Messanordnung, die die Stromaufnahme des Lastanschlusses bestimmt,
• – wenigstens einen Schalter, der die Last mit dem Netz verbindet oder vom Netz trennt,
• – wenigstens eine Steuerschaltung, die den Schalter in Abhängigkeit von den Messergebnissen der Messanordnung steuert,
• – wobei die Steuerschaltung die Last mittels des Schalters vom Netz trennt, wenn die von der Messanordnung gemessene Stromaufnahme der Last von einem gespeicherten Wert der Stromaufnahme der Last über einen vorgegebenen Toleranzwert hinweg abweicht.

For carrying out the method according to the invention, an electrical circuit is used, comprising:

• At least one network connection,
• At least one load connection,
• At least one measuring arrangement which determines the current consumption of the load terminal,
• At least one switch connecting or disconnecting the load from the mains,
• At least one control circuit which controls the switch in dependence on the measurement results of the measuring arrangement,
• - Wherein the control circuit disconnects the load from the network by means of the switch, when the current consumption of the load measured by the measuring arrangement deviates from a stored value of the current consumption of the load over a predetermined tolerance value.

advantageously, is the at least one switch as a mechanical or electronic switch designed, preferably as a relay or as a transistor. The advantage on a mechanical or electronic switch, like a relay or a transistor, is that they are controlled by a control voltage or current can be switched, such as they are common in digital circuits (+5 V). It can the switched power (supply voltage / current of the load) many times higher be, as the control voltage / the control current.

To an embodiment the invention is the at least one control circuit as a microcontroller designed, preferably as a microcontroller with associated or integrated storage unit. In the memory unit, the current consumption of the electrical appliance (Load) for all intended operating conditions of the electrical appliance stored as determined by the initial measurement. Furthermore you can These values are determined by the current consumption values of the electrical appliance be adjusted. The use of a microcontroller has the advantage that it is particularly suitable for matching two values compare and generate a control signal based on the comparison. Microcontrollers also have the advantage of being easy on their respective field of application can be adapted and that they are inexpensive are.

In a further embodiment According to the invention, the control circuit comprises at least one power supply unit. preferably an electronic power supply. This has the advantage that the control circuit via the Power supply supplied with the necessary supply voltage (eg +5 V) will, so no extra Power supply to be connected to the control circuit got to. The use of an electronic power supply has the advantage that this is easily manufactured and adapted to the circumstances can be adjusted.

According to a preferred embodiment of the invention, the electrical circuit comprises a control element, preferably a button, wherein an actuation of the operating element by a user after an activation of the load (Elektroge advises) connects the load back to the grid. This ensures that the user is informed by the electrical appliance on the non-intended operating state of the electrical appliance. Ideally, the user of the electrical appliance has found and remedied the cause of the non-intended operating state of the electrical appliance before it reconnects the electrical appliance to the mains by actuating the control element. If the user of the electrical appliance has not remedied the cause of the non-intended operating state of the electrical appliance, then the electrical appliance is immediately disconnected from the mains after operating the control element, since the electrical circuit would detect a non-intended operating state of the electrical appliance.

Around the user of the electrical appliance indicate whether the electrical circuit is active and / or whether the Load was disconnected from the mains, includes the electrical circuit preferably an optical display element. This may, for example, to one or more LEDs Act or a multi-colored LED.

In a non-intended operating condition step up Voltages and / or currents in the load circuit. To the control circuit from damage by such overvoltage and / or such an increased Protecting electricity is according to an embodiment the load circuit is galvanically isolated from the control circuit.

advantageously, the measuring arrangement is directly with the control circuit, preferably a microcontroller connected. This eliminates the need for a additional Conversion of the measurement signal with the resulting inaccuracies and the additional required Conversion unit. The measuring arrangement thus generates a signal that are processed by the control circuit without conversion can.

The The invention further relates to a device for connecting a Electrical appliance, preferably an electric heater, with the network comprising a prescribed electrical circuit, a Power plug and a socket for the electrical appliance. advantageously, The device has the form of a socket housing. socket Outlets are for example of timers or remote-controlled socket adapters known. A socket housing has a power plug, which is plugged into a standard power outlet. On the opposite Side of the socket housing is a connection socket for an electrical appliance arranged so that the electrical enclosure contained in the socket housing Circuit is connected between the mains and the electrical appliance.

alternative The invention relates to a device for connecting electrical appliances, preferably of electric heaters, with the network comprising a circuit described above, a power plug and at least two sockets for the electrical appliances, preferably in the form of a power strip. A power strip is used for simultaneous connection of several electrical appliances with the net.

In a further alternative embodiment the invention, the electrical circuit is integrated directly into an electrical appliance.

Also if at that time only it was described that the method according to the invention the current consumption of the electrical appliance measures and compares with stored values the power consumption of the electrical appliance, to the electrical appliance to unlock in non-intended operating states, is it a professional working in the field clear that the measurement of the current consumption of the electrical appliance by a voltage measurement can be replaced. This can, for example, the Voltage drop across a defined resistor connected in series the electrical appliance is switched, be measured. Changes the operating state of the electrical appliance, so changes also its resistance, whereby at the same time the voltage drop at the defined resistance changes because the applied mains voltage remains constant.

The inventive method, as well as the inventive electrical Circuit, is not limited to special electrical appliances. This means, depending on the area of use, from a very small one to one very high power consumption is measured. Advantageously, can the measuring arrangement for this purpose comprise a range switching, the before the measurement of the actual current consumption an area preselection meets. Advantage of this is that the downstream measuring arrangement at the selected Range can be adjusted, thereby reducing the measurement error becomes.

The Invention will be described below with reference to the drawings embodiments explained in more detail. It demonstrate:

1 a flowchart of a first embodiment of the method according to the invention,

2 a flowchart of a second embodiment of the method according to the invention,

3 a flowchart of a third embodiment of the method according to the invention,

4 a flowchart of a fourth embodiment of the method according to the invention,

5 a flowchart of a fifth embodiment of the method according to the invention,

6 a block diagram of an embodiment of the electrical circuit according to the invention,

7 an electrical circuit diagram to the block diagram from 6 ,

In 1 is a flow diagram of a first embodiment of the method according to the invention for detecting the operating state of an electrical appliance, in particular of electric heating appliances, and shown for activation of the electric heater in non-intended operating conditions. The procedure begins with a first-time measurement 1 the current consumption of the electrical appliance in all normal operating conditions of the electrical appliance. The intended operating states of the electrical appliance can be, for example, the operating states "heat" and "keep warm". The measured values of the current consumption of the electrical appliance for the intended operating conditions are stored 2 , For example, an "erasable electrically programmable read-only memory" (EEPROM) is used for storage.

The first time measuring 1 the power consumption of the electrical appliance in all normal operating conditions of the electrical appliance and storing the measured values 2 may also be referred to as initializing the method according to the invention. When initializing the method according to the invention, the method is adapted to the electrical appliance to be monitored.

After initializing the procedure will take a test 3 instead of whether the electrical appliance to be monitored is in operation. This exam 3 is carried out until the electrical appliance to be monitored is put into operation.

If the electrical appliance to be monitored is put into operation, the current consumption of the electrical appliance to be monitored is measured in a next step 4 , Used in measuring the current current consumption 4 If the electrical appliance to be monitored has been found to be switched off, the procedure returns to testing 3 the operation of the electrical appliance back.

If the electrical appliance to be monitored is in operation, the next step is the current measured current consumption 4 of the electrical appliance with the stored measured values 2 the power consumption of the electrical appliance to be monitored compared. The stored measured values 2 The current consumption of the electrical appliance to be monitored include a value for each intended operating state of the electrical appliance. The measured current consumption 4 is with each of these stored values 2 compared. Dips the measured current consumption 4 from all stored values 2 the current consumption of the electrical appliance for the intended operating conditions over a predetermined tolerance value away, the device is unlocked 6 because the electrical appliance to be monitored is in a non-intended operating condition.

Corresponds to the measured current consumption 4 with one of the stored values 2 the power consumption of the electrical appliance for a normal operating condition, or is within a predetermined tolerance range to one of the stored values 2 , so is the monitored electrical appliance in a normal operating condition.

Has the inventive method in the comparison 5 recognized that the electrical appliance to be monitored is in a normal operating condition, the method returns to the measurement of the current current consumption 4 back to the monitored electrical appliance.

The unlock 6 of the electrical appliance to be monitored in a non-intended operating condition should prevent damage to the electrical appliance and / or damage to objects in the vicinity of the electrical appliance to be monitored. For example, in an improper operating condition, the electrical appliance may become so hot that it burns. In the event of a fire of the electrical appliance, other objects may be damaged in the vicinity of the burning electrical appliance. An activation 6 of the electrical appliance in a non-intended operating condition prevents damage to the electrical appliance and the emergence of a fire within the electrical appliance at an early stage.

Has the electrical appliance to be monitored been disconnected? 6 , so it can only be put back into operation, if previously a control was pressed 7 , If this control element, which is designed for example as a button, not operated 7 , so the electrical appliance to be monitored remains in the unlocked state. If the operating element is actuated by a user of the electrical appliance to be monitored 7 , so the method returns to the measurement of the current current consumption 4 to oversee back home. If the user of the electrical appliance to be monitored has found and remedied the cause of the operating state of the electrical appliance that is not in accordance with the regulations, then at the next measurement, the current current consumption is determined 4 and the subsequent comparison 5 be determined that the electrical appliance to be monitored is in a normal operating condition and the electrical appliance can continue to be used. If the user of the electrical appliance to be monitored has not remedied the cause of the improper operating state of the electrical appliance, then the current consumption will be measured at the next measurement 4 and the subsequent comparison 5 again an unspecified operating condition can be detected so that the electrical appliance to be monitored again enabled 6 becomes.

Consequently is guaranteed that to be monitored electrical appliance can only continue to operate if the cause of the non-specified operating condition was found and fixed.

This in 2 illustrated embodiment of the method according to the invention differs from the embodiment 1 in that the stored value 2 the current consumption of the electrical appliance for the intended operating condition with the measured current value 4 adapted to the current consumption 8th will if no activation 6 was made. This adaptation 8th is advantageous because the power consumption of the monitored electrical appliance may change over time, for example, caused by the aging of the electronic components within the electrical appliance. In order to adapt the method according to the invention to these changed conditions, in the exemplary embodiment 2 the stored value 2 the current consumption of the electrical appliance for the intended operating condition with the measured current value of the power consumption 4 customized 8th , This can be done, for example, by storing the measured current value of the current consumption 4 can be realized in a list, wherein the list preferably comprises three or five values and, if necessary, the oldest value is deleted. In the comparison 5 the measured current consumption 4 with the stored values 2 Current consumption, all values in the list are taken into account.

On the other hand, it is also possible to obtain an average value from the stored value 2 form the current consumption of the electrical appliance and the measured current current consumption of the electrical appliance and store the mean value formed, the old stored value 2 the power consumption of the electrical appliance is deleted.

The adaptation 8th The stored values also have the advantage that the inventive method according to 2 can adapt to fluctuations in the supply voltage of the electrical appliance.

This in 3 illustrated embodiment of the method according to the invention differs from the method 2 in that an adaptation 9 the stored current consumption 2 only after switching off the electrical appliance to be monitored is performed. Through this subsequent and unique adaptation 9 is ensured that the inventive method according to 3 does not adapt to a slow and steady change in the operating state of the electrical appliance to be monitored from a normal operating condition to a non-intended operating condition, in which case it would not be able to detect the non-intended operating condition. Nevertheless, the embodiment yields 3 has the advantage that the method adapts to a change in the current consumption of the electrical appliance to be monitored, for example caused by aging of the electronic components within the electrical appliance to be monitored.

This in 4 illustrated embodiment of the method according to the invention differs from the previous embodiments in that after commissioning of the monitored electrical appliance and before measuring the current power consumption 2 of the electrical appliance, a timer is started 10 , The timer is stopped 11 if the electrical appliance to be monitored has been switched off.

Starting the timer 10 has the advantage that the operating time of the electrical appliance to be monitored is measured so that the electrical appliance to be monitored is enabled in the event of a conspicuously long operating time 6 can be. This can, for example, when comparing 5 the measured current consumption 4 of the electrical appliance with the stored values 2 the power consumption of the electrical appliance to be checked simultaneously, whether the electrical appliance to be monitored has exceeded a predetermined operating time.

After switching off the electrical appliance to be monitored and the resulting stopping of the timer 11 The predetermined value of the operating time can be adjusted with the measured operating time, such as the adjustment 9 the stored values 2 the current consumption of the electrical appliance with the measured current consumption 4 of the electrical appliance after switching off the electrical appliance, whereby the method according to the invention 4 to a change in the Be operating time of the electrical appliance adapts. The operating life of the electrical appliance may be prolonged, for example, by aging of a heating element, since it takes longer to reach a prescribed temperature.

At the in 5 illustrated embodiment of the method according to the invention is during the first measurement 1 In addition, the duration of the respective intended condition is measured and stored 2 , After commissioning of the electrical appliance to be monitored 3 Two timers are started 10 ,

After a comparison 5 the measured current consumption 4 of the electrical appliance with the stored values 2 the current consumption of the electrical device, the inventive method is able to the intended operating conditions based on the comparison 5 to distinguish. Returns a check of the operating state 12 in that the operating state has not changed, the method for measuring the current current consumption returns 4 back to the monitored electrical appliance.

Returns the test of the operating status 12 in that the operating state of the electrical appliance to be monitored has changed, the second started timer is stopped 13 , In a next step of the process according to 5 the stored current consumption of the electrical appliance and the duration of the operating state are adjusted for the operating state before the change 14 and saved. Then the second timer is started again 15 and the method returns to measuring the current current consumption 4 back to the monitored electrical appliance.

The adjustment of the current consumption and the duration of the operating state for each operating state 14 has the advantage that changes that affect only one operating state, by the inventive method 5 be recognized and compared with the measured current consumption 4 be taken into account. For example, only the duration of the "heating" operating state may be prolonged because the heating element has lost effectiveness, while the "keep warm" operating state is independent thereof. In that case, the method is able to detect when the operating state "heating" is not left because the associated thermocouple is damaged.

If one of the two timers exceeds one of the stored values 2 , then the electrical appliance to be monitored is enabled 6 , If the electrical appliance is not disconnected, both timers are stopped after switching off the electrical appliance to be monitored and, as described above, the stored current consumption and duration for the detected operating state adjusted and additionally stored the total operating time 16 ,

In all the aforementioned embodiments of the method according to the invention, the electrical device is enabled when a predetermined maximum power consumption is exceeded 6 , regardless of a deviation of the measured current consumption 4 from the stored values of the power consumption 2 of the electrical appliance.

In 6 the block diagram of an electrical circuit for performing one of the aforementioned methods is shown. The electrical circuit comprises a mains connection 17 , a load connection 18 , a measuring arrangement 19 , which is the current consumption of the load terminal 18 certainly, a switch 20 , which connects the load to the mains or disconnects from the mains, a control circuit 21 that the switch 20 depending on the measurement results of the measuring arrangement 19 controls, the control circuit 21 the load by means of the switch 20 disconnects from the mains when the of the measuring arrangement 19 measured current consumption of the load deviates from a stored value of the current consumption of the load over a predetermined tolerance value.

Furthermore, the electrical circuit according to 6 a fuse 22 that the mains connection 17 is downstream. The fuse 22 protects the electrical circuit according to the invention from an overvoltage or too high a current. Thus, for example, a voltage spike at the mains connection 17 do not damage the electrical circuit according to the invention.

For generating a supply voltage for the measuring arrangement 19 , the switch 20 and the control circuit 21 includes the inventive electrical circuit according to 6 continue a power supply 23 , The power supply 23 converts the at the mains connection 17 applied mains voltage in one for the measuring arrangement 19 , the switch 20 and the control circuit 21 usable supply voltage um.

Furthermore, the inventive electrical circuit according to 6 a control 24 , which depends on the user of the electrical circuit 6 is pressed to reconnect the load after disconnecting with the mains connection 17 connect to.

For status indication, the electrical circuit further includes a bi-color LED 25 wherein the one color of the LED, for example green, indicates that the electrical circuit is active and the load port 18 monitored and the second color, such as red, indicates that the load port 18 from the control circuit 21 by means of the switch 20 from the mains connection 17 was separated. Advantageously, the red LED flashes to indicate to a user who can not distinguish the colors red and green that the load port 18 from the mains connection 17 was separated.

The desk 20 is designed as a mechanical or electronic switch, for example as a relay or as a transistor. The advantage of this is that by means of a small control voltage or a small control current, a high load voltage or a high load current can be switched. Thus, for example, that of the control circuit 21 generated control signal directly from the switch 20 be recycled without having to be converted beforehand.

The control circuit 21 is designed as a microcontroller, preferably as a microcontroller with associated or integrated memory unit. In the associated or built-in memory unit, the results of the initial measurement 1 be stored and possibly later replaced by adjusted values.

With the power supply 23 It is an electronic power supply, as such a power supply can produce different supply voltages and yet is simple and inexpensive.

The measuring arrangement 19 separates the load circuit galvanically from the control circuit. This has the advantage that too high a load voltage or too high a load current, which is the measuring arrangement 19 could have no effect on the control circuit, so that possibly only the measuring arrangement 19 must be exchanged.

During the intended use of the electrical circuit, the measuring arrangement generates 19 a signal coming directly from the control circuit 21 can be processed.

7 shows the electrical circuit diagram of the block diagram after 6 , The power connection 17 is the fuse 22 downstream. Behind the fuse 22 is the electronic power supply 23 connected. The power supply 23 includes in addition to the resistors R1-R4 a rectifier circuit 26 , the capacitors C1-C5, also the IC1 27 and provides the supply voltage V + and +5V.

Parallel to the power supply 23 is the series circuit of switches 20 and measuring arrangement 19 connected. At the switch 20 it is a relay and the measuring arrangement 19 an electronic power meter.

The of the measuring arrangement 19 determined current consumption of the load connection 18 becomes the control circuit 21 transfer.

At the control circuit 21 is an ATMega8 microprocessor from Atmel. This microprocessor 21 compares this from the measuring arrangement 19 supplied signal with predetermined values and switches depending on the relay 20 over the transistor 28 ,

The operating element 24 and the two-color LED 25 are each with the microcontroller 21 connected.

The electrical circuit after 6 and 7 can be integrated either in an unillustrated socket housing or directly in an unillustrated electrical appliance.

1

first-time measure up

2

to save the measured values

3

Testing operation

4

measure up the current current consumption

5

to compare

6

Unlock

7

operating element actuated

8th

To adjust of the stored value

9

Adaptation

10

begin timer

11

Stop timer 1

12

Checking the operating state

13

Stop timer 2

14

Adaptation Current consumption and operating time

15

Start timer 2

16

Adaptation Current consumption, operating time and total operating time

17

mains connection

18

load connection

19

measuring arrangement

20

switch

21

control circuit

22

fuse

23

power adapter

24

operating element

25

LED

26

rectifier

27

IC1

28

transistor

Claims (20)

Method for detecting the operating state of an electrical appliance, in particular of electric heating appliances, and for disconnecting the electrical appliance in operating states that are not determined, comprising the steps: - initial measurement ( 1 ) the current consumption of the electrical appliance in all intended operating states of the electrical appliance, - storing the measured values ( 2 ) the current consumption of the electrical appliance for the intended operating conditions, - permanent or regular measurement of the current current consumption ( 4 ) of the electrical appliance during operation, - Compare ( 5 ) of the measured current consumption ( 4 ) of the electrical appliance with the stored values ( 2 ) of the power consumption of the electrical appliance, - Activation ( 6 ) of the electrical appliance from the supply voltage when the measured current consumption ( 4 ) from the stored values ( 2 ) of the power consumption of the electrical device over a predetermined tolerance value away. Method according to claim 1, characterized in that the stored value ( 2 ) of power consumption ( 4 ) of the electrical appliance for the intended operating state with the measured current value of the current consumption ( 4 ) customized ( 8th ), if no activation ( 6 ) was made. A method according to claim 2, characterized in that a list with at least the last three measured values of power consumption ( 4 ) of the electrical appliance is stored for each intended operating state of the electrical appliance, preferably with the five last measured values of the current consumption, wherein in each case the oldest measured value is deleted if necessary. Method according to claim 2, characterized in that an average value from the stored value ( 2 ) the power consumption of the electrical appliance for the intended operating condition and the measured value of the power consumption ( 4 ) of the electrical device for the operating state is formed and stored, whereby the previous stored value is deleted. Method according to one of claims 1 to 4, characterized in that in addition to the power consumption of the electrical appliance for the various intended operating conditions and the duration of power consumption of the electrical appliance for the intended operating conditions is measured and stored, the electrical appliance enabled ( 6 ) is when the measured duration of the power consumption of the electrical appliance exceeds the stored time duration of the power consumption of the electrical appliance for the intended operating state by a predetermined period of time. Method according to one of claims 1 to 5, characterized in that the electrical appliance after a predetermined time enabled ( 6 ) becomes. Method according to one of claims 5 to 6, characterized in that the stored time duration of the power consumption of the electrical device for the intended operating condition with the measured time duration of the current consumption of the electrical appliance for the intended operating condition is adjusted ( 14 ), preferably by storing a list of the last measured values or by storing an average value. Method according to one of claims 1 to 7, characterized in that the electrical appliance is activated when a predetermined maximum current consumption is exceeded ( 6 ), regardless of a deviation of the measured current consumption ( 4 ) from the stored values of the current consumption ( 2 ) of the electrical appliance. Method according to one of claims 1 to 8, characterized that several electrical appliances monitored simultaneously become. Electrical circuit for carrying out the method according to one of claims 1 to 9, comprising: - at least one network connection ( 17 ), - at least one load connection ( 18 ), - at least one measuring arrangement ( 19 ), the current consumption of the load terminal ( 18 ), - at least one switch ( 20 ), which connects the load to the mains or disconnects from the mains, - at least one control circuit ( 21 ), the switch ( 20 ) depending on the measurement results of the measuring arrangement ( 19 ), wherein the control circuit ( 21 ) the load by means of the switch ( 20 ) disconnects from the mains when the measuring equipment ( 19 ) measured current consumption of the load deviates from a stored value of the current consumption of the load over a predetermined tolerance value. Electrical circuit according to claim 10, characterized in that the switch ( 20 ) is designed as a mechanical or electronic switch, preferably as a relay or as a transistor. Electrical circuit according to claim 10 or 11, characterized in that the control circuit ( 21 ) is designed as a microcontroller, preferably as a microcontroller with associated or integrated memory unit. Electrical circuit according to one of claims 10 to 12, characterized in that the electrical circuit is a power supply ( 23 ), preferably an electronic power supply. Electrical circuit according to one of claims 10 to 13, characterized in that the electrical circuit is an operating element comprises, preferably a button, wherein an actuation of the Operating element by a user after activation of the Load connects the load back to the grid. Electrical circuit according to one of claims 10 to 14, characterized in that the electrical circuit is an optical display element ( 25 ) indicating to a user that the electrical circuit is active and / or whether the load has been disconnected from the mains. Electrical circuit according to one of claims 10 to 15, characterized in that the load circuit galvanically from Control circuit is disconnected. Electrical circuit according to one of claims 10 to 15, characterized in that the measuring arrangement ( 19 ) directly to the control circuit ( 21 ), preferably a microcontroller. Device for connecting an electrical appliance, preferably of an electric heater with which A network comprising an electrical circuit according to any one of claims 10 to 17, a power plug and a socket for the electrical appliance, preferably in the form of a socket housing. Device for connecting electrical appliances, preferably of electric heaters, with the A network comprising an electrical circuit according to any one of claims 10 to 17, a power plug and at least two sockets for the electrical appliances, preferably in the form of a power strip. electrical appliance comprising an electrical circuit according to one of claims 10 to 17, characterized in that the electrical circuit in the electrical appliance is integrated.