Abstract: To determine an AC insulation resistance between the AC connections of an inverter and a ground potential, the AC connections are connected to an AC energy sink in an emergency standby operation in order to transmit energy from a DC energy source to an AC energy sink and an insulation test is performed in emergency standby operation. An AC fault current flowing between an AC connection and the ground potential is determined, and the AC insulation resistance is calculated from the AC fault current.

Abstract: A method for operating an inverter includes applying, via a switching unit of the inverter, an AC voltage to a phase line in which a filter inductor is arranged, determining a coil current (iL) of the filter inductor and determining a coil voltage (uL) of the filter inductor, determining a first value (L(Ix)) of the filter inductor for a first value of the coil current (Ix), determining an inductance profile of the filter inductor with respect to the coil current, using the determined first value of the filter inductance and optionally using the at least one determined further value of the filter inductance, and controlling the switching unit of the inverter, via a control unit, to generate an alternating current in the phase line. At least one parameter of the control process is continuously adapted to the momentary coil current according to the determined current-dependent inductance profile.

Abstract: In order to achieve improved single-phase operation of an inverter having a first input pole and a second input pole and including at least three phase branches, each having at least one upper power switch and at least one lower power switch connected in series to the at least one upper power switch via an output pole a switching unit is provided. The switching unit is designed to switch the inverter from multi-phase operation to single-phase operation by closing a center point connection switch in order to connect the third output pole to the DC link center point. The switching unit is further designed, in single-phase operation, to effect a control of the upper and lower power switch of the third phase branch for symmetrizing the DC link voltages at the first and second DC link capacitors.

Abstract: A switching arrangement of an inverter with a filter circuit and a grid relay. For the filter circuit use is made of an equivalent circuit consisting of effective filter inductance, from filter inductance and topology of the filter circuit and effective filter capacitance, from the filter capacitance and topology of the filter circuit. The effective filter inductance and the effective filter capacitance are system parameters. To determine system parameters, a voltage pulse is applied between a first conductor output and a second conductor output when the grid relay is open; the first conductor output and the second conductor output are connected via the switching arrangement to form a closed oscillating circuit a current value of the effective filter inductance and the effective filter capacitance is determined from a current curve and/or voltage curve in the resonant circuit as system parameters for controlling the switching arrangement.

Abstract: In a method for operating an inverter for converting DC voltage into AC voltage, having at least one DC/DC step-up converter for converting a DC input voltage applied at the step-up converter DC input into an output voltage higher by a voltage stroke, an intermediate circuit, a DC/AC converter and an AC output for connection to a supply network and/or consumers, a voltage ripple is superimposed on the intermediate circuit voltage and in each step-up converter a switch is switched on/off with a specific switching frequency and a specific duty cycle, for measuring the output voltage of each step-up converter and the intermediate circuit voltage including the voltage ripple. A minimum voltage stroke of each step-up converter is dynamically calculated as a function of the respective measured step-up converter input voltage and the measured intermediate circuit voltage ripple, which minimizes the intermediate circuit voltage setpoint.

Abstract: A method for operating an inverter includes applying, via a switching unit of the inverter, an AC voltage to a phase line in which a filter inductor is arranged, determining a coil current (iL) of the filter inductor and determining a coil voltage (uL) of the filter inductor, determining a first value (L(IX)) of the filter inductor for a first value determining an inductance profile of the filter inductor with respect to the coil current, using the determined first value of the filter inductance and optionally using the at least one determined further value of the filter inductance, and controlling the switching unit of the inverter, via a control unit, to generate an alternating current in the phase line. At least one parameter of the control process is continuously adapted to the momentary coil current according to the determined current-dependent inductance profile.

Abstract: In a method for operating an inverter for converting DC voltage into AC voltage, having at least one DC/DC step-up converter for converting a DC input voltage applied at the step-up converter DC input into an output voltage higher by a voltage stroke, an intermediate circuit, a DC/AC converter and an AC output for connection to a supply network and/or consumers, a voltage ripple is superimposed on the intermediate circuit voltage and in each step-up converter a switch is switched on/off with a specific switching frequency and a specific duty cycle, for measuring the output voltage of each step-up converter and the intermediate circuit voltage including the voltage ripple. A minimum voltage stroke of each step-up converter is dynamically calculated as a function of the respective measured step-up converter input voltage and the measured intermediate circuit voltage ripple, which minimizes the intermediate circuit voltage setpoint.

Abstract: The data carriers (T I, T2, T3, T4) of those objects (1, 2, 3, 4) whose presence is to be checked, are allocated to a check group (ÜG), in a method of checking the presence of objects characterized by noncontact readable data carriers, wherein each noncontact readable data carrier can be identified uniquely or in groups. Data carriers (T1 to T6) are detected by data carrier reading means (5) and it is detected whether at least one of the detected data carriers (T1 to T6) is allocated to an activation group (AG). If at least one of the detected data carriers (T4, T5) is allocated to the activation group (AG), the presence check is activated, while it is checked during the presence check whether all the data carriers (T1 to T4) allocated to the check group (ÜG) are detected by the data carrier reading means (5) and, if not, an alarm signal (AL) is transmitted.

Abstract: The invention specifies an apparatus and a method for monitoring a building opening which is closed with a closure element (6, 6a . . . 6n) which is not fully transparent. The apparatus comprises a pattern (M), which is arranged on one side of the closure element (6, 6a . . . 6n) or is projected onto this side, and a detection unit (7a . . . 7e) which is aligned with this pattern (M). A comparison unit compares the actual pattern (M) detected by the detection unit (7a . . . 7e) with a desired pattern and triggers an alarm if the difference between the actual pattern (M) and the desired pattern exceeds a predefinable threshold.

Abstract: The invention specifies an apparatus and a method for monitoring a building opening which is closed with a closure element (6, 6a . . . 6n) which is not fully transparent. The apparatus comprises a pattern (M), which is arranged on one side of the closure element (6, 6a . . . 6n) or is projected onto this side, and a detection unit (7a . . . 7e) which is aligned with this pattern (M). A comparison unit compares the actual pattern (M) detected by the detection unit (7a . . . 7e) with a desired pattern and triggers an alarm if the difference between the actual pattern (M) and the desired pattern exceeds a predefinable threshold.

Abstract: A system comprises at least one contactless readable data carrier (1) which can be attached to a wheel (100) of a vehicle and a reader (10) which can be arranged on the vehicle to receive electromagnetic signals (ES) emitted by the data carrier (1). The reader (10) is designed to determine the revolutions of the wheel (100) from the field strength fluctuation of the received electromagnetic signals (ES), the reader (10) having calculation means (19) designed to calculate from the revolutions and a wheel periphery reference value (RU) determined by the reader and allocated to the wheel (100), such as circumference, diameter or radius, a distance covered by a point on the wheel periphery and/or values derivable therefrom such as the peripheral speed (UV) of the wheel (100).

Abstract: A method and a device (1) for deterring children and adolescents from using an audio and/or audiovisual device (1), especially a TV set or a radio, while censored programs (X-Prog) are played by said device (1), said method comprising outputting an annoyance audio signal (AN) from the audio and/or audiovisual device (1) simultaneously with the censored program (X-Prog), wherein the annoyance audio signal (AN) has a frequency that can be heard by children and adolescents but is above the hearing threshold of adults.

Abstract: A system comprises at least one contactless readable data carrier (1) which can be attached to a wheel (100) of a vehicle and a reader (10) which can be arranged on the vehicle to receive electromagnetic signals (ES) emitted by the data carrier (1). The reader (10) is designed to determine the revolutions of the wheel (100) from the field strength fluctuation of the received electromagnetic signals (ES), the reader (10) having calculation means (19) designed to calculate from the revolutions and a wheel periphery reference value (RU) determined by the reader and allocated to the wheel (100), such as circumference, diameter or radius, a distance covered by a point on the wheel periphery and/or values derivable therefrom such as the peripheral speed (UV) of the wheel (100).

Abstract: The data carriers (T I, T2, T3, T4) of those objects (1, 2, 3, 4) whose presence is to be checked, are allocated to a check group (ÜG), in a method of checking the presence of objects characterized by noncontact readable data carriers, wherein each noncontact readable data carrier can be identified uniquely or in groups. Data carriers (T1 to T6) are detected by data carrier reading means (5) and it is detected whether at least one of the detected data carriers (T1 to T6) is allocated to an activation group (AG). If at least one of the detected data carriers (T4, T5) is allocated to the activation group (AG), the presence check is activated, while it is checked during the presence check whether all the data carriers (T1 to T4) allocated to the check group (ÜG) are detected by the data carrier reading means (5) and, if not, an alarm signal (AL) is transmitted.

Abstract: The invention specifies a method and an arrangement for testing and maintaining a switching center in a telecommunications network and the lines and appliances connected thereto, where control is effected using a test unit provided for this purpose which is connected to any digital subscriber line. This results in a significant increase in the scope of use for the test system, simple introduction of new test methods, performance of extensive tests with a single test unit, and fast and secure data transmission.