Abstract: A method tests a piezo key sensing circuit having a piezo element and verifies that it is properly functioning. A capacitance of the piezo element is discharged. Then the capacitance of the piezo element is charged during a predetermined time period. An output signal of the piezo element is measured during the predetermined time period resulting in a measured output signal. An operating condition of the piezo key sensing circuit is determined based on the measured output signal.

Abstract: A building automation and building information system has a central unit, at least one control unit and first components. The central unit is connected to the at least one control unit via a bidirectional data line, as means for reception of data from the at least one control unit, and means for open-loop and/or closed-loop control of the at least one control unit. Each control unit is associated with at least one first component, to which the control unit is connected by radio. The control unit has means for open-loop and/or closed-loop radio control of the associated first components. The first components associated with each control unit can be connected to one another by radio. The central unit, the at least one control unit and the first components each have a plug-and-play capability.

Abstract: A circuit configuration detects zero-crossings and/or a brownout condition. The circuit configuration contains a zero-crossing detection circuit, a brownout detection circuit, an isolation and digitization circuit connected to the zero-crossing detection circuit and the brownout detection circuit, and a filtering circuit connected to the isolation and digitization circuit. The single circuit configuration can be used for detecting zero-crossings of single-phase and multi-phase systems as well as ascertaining a brownout condition of either the single-phase or the multi-phase systems.

Abstract: A method for controlling a polyphase inverter that includes a number of half bridges connected into an intermediate voltage circuit and center taps between switching elements. By cyclically switching the switching elements, the respective center taps of the half bridges are connected to an upper intermediate circuit rail or to a lower intermediate circuit rail of the intermediate voltage circuit according to the principle of pulse width modulation. The switching elements of at least one half bridge are driven in a modified manner, at least in some time intervals, in that the switching pulses of at least two consecutive periods of the pulse width modulation are concatenated directly in time as one switching pulse. In this way, the switching frequencies of the correspondingly driven switching elements and thus the switching losses of the latter can be further reduced.

Abstract: A rotary knob operator control apparatus for an electrical domestic appliance has a mounting board on a side of an operator control panel facing away from a user, a first electrode configuration on the mounting board and a substantially annular operator control element on a side of the operator control panel facing toward the user. The operator control element has a second electrode configuration and a holding device for the operator control element on the operator control panel. The operator control element rotates about an axis perpendicular to the operator control panel. The operator control element is latched relative to the operator control panel in predefined rotary positions by a latching device, so the second electrode configuration on the operator control element is oriented in a predefined manner relative to the first electrode configuration. An electrical domestic appliance having at least one rotary knob operator control apparatus is also provided.

Abstract: A circuit configuration for operating a household device contains a power supply connector, an electrical load that is connected via a power connection cable to the power supply connector, and a controller for an endangering component. The controller is connected via a power connection cable to the power supply connector. A device for switching the controller on and off is arranged between the controller and the power supply connector. Safety equipment for disconnecting the controller from the power supply connector is arranged between the power supply connector and the device for switching. In order to supply the controller with electrical power even when the safety equipment is active, the electrical load is connected between the power supply connector and the safety equipment. A connecting cable is provided that connects the controller via the electrical load to the power supply connector, and in which the device for switching is arranged.

Abstract: A touch-sensitive pushbutton switch includes an optical sensor, in particular an infrared sensor, and an evaluation circuit. The evaluation circuit is able, through the use of a reference device, to set a sensitivity of the optical sensor in dependence on a detected basic level of an evaluation signal.

Abstract: A diagnostic circuit is configured for connecting to a unit under test that has a load and a sinusoidal source. The diagnostic circuit includes a voltage sensing device that has an input for sensing a signal, a first terminal for connecting to the load, a second terminal for connecting to the sinusoidal source, and a relay connected between the first and second terminals for connecting the sinusoidal source to the load. Clamping diodes are provide for clamping a sinusoidal signal and include a first clamping diode connected between a D/C voltage source and the input and a second clamping diode connected between ground and the input. A resistor is connected between the D/C voltage source and the first terminal. The diagnostic circuit verifies the operational functionality of the load, related wiring and connections.

Abstract: A method controls a three-phase converter with a voltage intermediate circuit by pulse-width modulation for supplying a polyphase system, in particular a three-phase machine. The converter is operated with at least two different modulation methods which are selected from among the group of modulation methods which includes single-phase switching, two-phase switching and three-phase switching, and for changeovers to be made between the at least two different modulation methods depending on the operating state of the polyphase system.

Abstract: An LED-based lighting system is operated with a time-based process. The LEDs are first turned on by energizing the system at full power. After a predetermined time period, which is selected so that the junction temperature of the LEDs does not reach a critical temperature, the current supply is ramped down to a steady-state supply. The steady-state current is maintained as long as the light is turned on. When the light is turned on the next time and the LEDs have not cooled down all the way, as determined by the time that has expired since the LEDs were last lit, the full-power time period is shortened accordingly.

Abstract: A diagnostic circuit is configured for connecting to a unit under test that has a load and a sinusoidal source. The diagnostic circuit includes a voltage sensing device that has an input for sensing a signal, a first terminal for connecting to the load, a second terminal for connecting to the sinusoidal source, and a relay connected between the first and second terminals for connecting the sinusoidal source to the load. Clamping diodes are provide for clamping a sinusoidal signal and include a first clamping diode connected between a D/C voltage source and the input and a second clamping diode connected between ground and the input. A resistor is connected between the D/C voltage source and the first terminal. The diagnostic circuit verifies the operational functionality of the load, related wiring and connections.

Abstract: A system and method for controlling automatic defrost of a refrigerator device adaptively moves the defrost cycle to a time period of comparatively low compressor activity based on an evaluation of compressor usage over a cyclically recurring time interval. An adaptive defrost controller (ADC) analyzes stored data to develop a profile for compressor activity vs. time. From this profile, high compressor activity times of the time interval are distinguished from low compressor activity times in the time interval and a defrost cycle is scheduled based on the results of the analyzed data.

Abstract: An apparatus for opening and/or closing a door of a domestic appliance, such as, for example, an oven, a refrigerator and the like, has a drive apparatus for the automatic opening and/or closing of the door and an actuating device which is operable by a user for activating the drive apparatus in order to open or to close the door.

Abstract: An operator control apparatus for an electrical household appliance has an operator control panel on that side of the operator control apparatus that faces a user and defines an operator control area. A functional assembly is arranged on that face of the operator control panel that is averted from the user. The functional assembly has touch- and/or proximity-sensitive touch-operated switch. The at least one touch-operated switch of the functional assembly is positioned so as to correspond to operator control area of the operator control panel. A connecting apparatus is permanently connected to the operator control panel and releasably connected to the functional assembly, or in the alternative it is permanently connected to the functional assembly while it is releasably connected to the operator control panel. In this way, the functional assembly is releasably attached to the operator control panel but without play.

Abstract: A method for controlling a polyphase inverter that includes a number of half bridges connected into an intermediate voltage circuit and center taps between switching elements. By cyclically switching the switching elements, the respective center taps of the half bridges are connected to an upper intermediate circuit rail or to a lower intermediate circuit rail of the intermediate voltage circuit according to the principle of pulse width modulation. The switching elements of at least one half bridge are driven in a modified manner, at least in some time intervals, in that the switching pulses of at least two consecutive periods of the pulse width modulation are concatenated directly in time as one switching pulse. In this way, the switching frequencies of the correspondingly driven switching elements and thus the switching losses of the latter can be further reduced.

Abstract: A diagnostic circuit for trouble shooting electronic control units of appliances includes a voltage sensing and signal generation device with an input/output and an input. The circuit includes first terminals for connecting to the load and second terminals for connecting to the two lines of the sinusoidal source. One of the first terminals is connected to the input/output, and another one of the first terminals is connected to the input. A relay is connected between one of the second terminals and the input/output. Another relay is connected between another one of the second terminals and the input. A first diode pair with clamping diodes is connected to the input/output, and a second diode pair first diode pair with clamping diodes is connected to the input.

Abstract: A DC/DC converter circuit configuration contains a rectifier configuration, an inductance and at least one circuit breaker for switching the inductance on its input side. When controlling the circuit configuration, an off time of the circuit breaker is variably changed on the basis of the output power of the circuit configuration and the circuit breaker is respectively switched on in the region of a minimum of a voltage curve across the circuit breaker in order to minimize the switching losses and achieve a high level of efficiency.

Abstract: An AC voltage controller has two transistors which can be positioned between two AC voltage terminals in series with a load. The two transistors are connected in series in such a way that their respective source terminals are connected to one another. The AC voltage controller also contains a signal generator for generating a switching signal for actuating the two transistors, a buffer which is connected downstream of the signal generator and which is set by the signal generator in order to actuate the two transistors. An actuation circuit or driver circuit is connected downstream of the buffer, for the purpose of actuating the two transistors in accordance with the set state of the buffer. A current-limiting circuit is provided for limiting or switching off the current through the two transistors in the case of an excessively large current through the load.

Abstract: An actuating device for a heating element valve has a drive motor with a motor shaft, an actuator, and a rotation-linear conversion drive. The conversion drive is coupled on the drive side to the motor shaft and on the output side to the actuator and converts a rotational movement of the motor shaft into a linear movement of the actuator. The rotation-linear conversion drive further has a cam disc on the output side which is provided on its outer circumferential periphery with a plurality of step segments each having a substantially constant distance from the axis of the cam disc. The step segments are connected via connecting segments with a variable axle spacing.

Abstract: An exhaust hood has a fan apparatus for drawing away discharge air from a cooking appliance, which is arranged beneath the exhaust hood and which has at least one cooking area. A temperature detection device detects a temperature of at least one cooking area of the cooking appliance and a cooking vapor detection device detects cooking vapors in the discharge air which is drawn away by suction by the fan apparatus. A control device of the exhaust hood switches on the fan apparatus depending on a temperature which is detected by the temperature detection device and controls a suction-removal power of the fan apparatus depending on cooking vapors which are detected by the cooking vapor detection device.