Abstract: An integrator and a circuit-breaker are disclosed, the integrator being in the form of a passive symmetrical low-pass filter having an integration capacitor. In order to make it possible to temporally integrate an electrical signal in an improved manner, it is proposed in at least one embodiment that provision be made of a differential amplifier having two amplifying elements each having an input, that the two amplifying elements be coupled to one another in order to generate a differential signal, that the inputs of the two amplifying elements be connected to one another via the integration capacitor, and that each amplifying element be positively fed back to its input via a feedback loop in such a manner that the two amplifying elements together form a negative input resistance in parallel with the integration capacitor.

Abstract: An integrator and a circuit-breaker are disclosed, the integrator being in the form of a passive symmetrical low-pass filter having an integration capacitor. In order to make it possible to temporally integrate an electrical signal in an improved manner, it is proposed in at least one embodiment that provision be made of a differential amplifier having two amplifying elements each having an input, that the two amplifying elements be coupled to one another in order to generate a differential signal, that the inputs of the two amplifying elements be connected to one another via the integration capacitor, and that each amplifying element be positively fed back to its input via a feedback loop in such a manner that the two amplifying elements together form a negative input resistance in parallel with the integration capacitor.

Abstract: A power switch includes an electronic overcurrent protection trigger, which receives the power supply thereof from the power supply network monitored by the power switch. In at least one embodiment, the display device of the power switch acquires the power supply thereof from the power supply network monitored by the power switch, and an electronic device powered with voltage from the power supply network monitored by the power switch controls the turning on and off of the background illumination of the electronic display device, which obtains the voltage supply thereof from the power supply network monitored by the power switch, with the aid of an electronically controllable switch as a function of the measured values detected in a measuring device of the electronic device. A method for controlling the turning on and off of the background illumination of a display device of a power switch is also disclosed.

Abstract: A method and a circuit are disclosed for amplifying the input signals of an electronic overcurrent release of low-voltage circuit breakers with a selectable amplification factor. The electronic overcurrent release includes at least one integrating condenser on the input side, and at least one pre-amplifier and a microprocessor. According to at least one embodiment of the invention, a resistance is coupled to a switch in series, parallel to an integrating condenser, and the switch is switched by way of the microprocessor in a pulsewidth-modulated manner. In this way, the effectively active resistance value of the inserted resistances is inversely increased proportionally to the pulsewidth repetition rate, thus obtaining an extremely wide regulating range.

Abstract: A low-voltage power circuit breaker includes an electronic overcurrent release, which draws its operating energy from the power supply system monitored by the low-voltage power circuit breaker, and an operating-state detection device. Since it is possible for the power circuit breaker to switch to a short circuit on connection, it may be appropriate for no undelayed tripping of the power circuit breaker to be permitted directly after connection, or for the tripping time for the delayed tripping to be altered. Provision is made for the operating-state detection device to be a device for detecting a connection operation, whose output signal is fed to the overcurrent release, which sets a different disconnection time for the low-voltage power circuit breaker at the beginning of a connection operation for a predetermined period of time.

Abstract: Data memories are used to represent the characteristic values of the properties of the circuit-breaker and the associated current transformer. A cable harness uses a writeable electronic memory module which is inserted into one of the interconnecting cables between the current transformer(s) and the overcurrent trip as the data memory.

Abstract: According to the invention a bypass circuit (4) trips a power circuit breaker, independently of an existing electronic overcurrent trip (2), as instantaneously as possible when a short-circuit occurs. To achieve this, the bypass circuit (4) is supplied by its own current sensor (3) that is configured as a current transformer in order to charge a capacitor (C); until a threshold value circuit (5) responds. The charge of the capacitor (C) is then fed to a separate tripping magnet (F2) or to a combined tripping magnet (F3) comprising separate coils for the two tripping paths.

Abstract: Data memories are used to represent the characteristic values of the properties of the circuit-breaker (10) and the associated current transformer (17). Known assemblies requires a large number of plug and socket connections and are limited with regard to the number of parameters that can be stored. The inventive assembly uses a writeable electronic memory module which is inserted into one of the interconnecting cables (1) between the current transfomer(s) and the overcurrent trip (18) as the data memory.

Abstract: In power circuit breakers including a current transformer with a current detection coil without any iron and including an integration circuit connected downstream from the current detection coil, the unavoidable time constant of the integration circuit can lead to spurious trappings. This is avoided by a method in which the instantaneous values of the current are detected and stored at defined periodic intervals. The stored measured values are compared on the basis of polarity and magnitude. If it is found that the stored values have the same polarity and fall monotonally, it is assumed that the DC element is originating from the integrator and a tripping inhibit signal is set in the electronic release of the power circuit breaker.

Abstract: In power breakers which have a current transformer (6) with a current detection coil (7) without any iron and have an integration circuit (8) connected downstream from the current detection coil (7), the unavoidable time constant of the integration circuit (8) can lead to spurious trippings. This is avoided by a method in which the instantaneous values of the current are detected and stored at defined periodic intervals (n, n+l, n+2). The stored measured values are compared on the basis of polarity and magnitude. If it is found that the stored values have the same polarity and fall monotonally, it is assumed that the DC element is originating from the integrator (8) and a tripping inhibit signal is set in the electronic release of the power breaker.