Abstract: An electronic switchgear operating contact-free, having a presence indicator which can be externally affected, a switching amplifier disposed downstream of the presence indicator an electronic switch controllable by the presence indicator via the switching amplifier a supply circuit for the provision of the supply voltage for the presence indicator and for the switching amplifier and a delay circuit preventing activating pulses. The supply circuit has a voltage and/or current regulator. In the electronic switchgear in accordance with the invention activating pulses are prevented with a higher degree of assurance than in the state of the art, namely based on the fact that the delay circuit becomes active, i.e. the delay time starts, only after the voltage and/or current regulator has started to operate.

Abstract: A contact-free operating electronic switchgear, having an oscillator capable of being externally affected, a switching amplifier with at least two operating units disposed downstream of the oscillator, an electronic switch, which can be controlled by the oscillator via the switching amplifier, and a supply circuit for the provision of the supply voltage for the oscillator and for the switching amplifier, is shown and described. In electronic switchgear operating contact-free in accordance with the invention the maximum switching frequency is considerably increased in that a control circuit is provided between the two operating units of the switching amplifier and the oscillator and that the oscillator is controlled by means of the control circuit in such a way that the oscillator also oscillates in the affected state.

Abstract: A proximity switch or contactless switch circuit comprises within a casing a flexible insulating carrier provided along a component side with a multiplicity of electronic components connected by conductive strips to form the contactless or proximity switch circuit. An extension of the carrier or the opposite side of the carrier are provided with continuous conductive coatings so that when the carrier is folded or rolled within the casing, a portion of the carrier strip provided with the coating or layer forms an additional shield.

Abstract: A contactless motion detector, specifically an oscillator whose signal amplitude is attenuated or enhanced by the approach of a monitored metallic element, is periodically switched for brief periods into its alternate state by a train of short test pulses giving rise to corresponding checking pulses that are superimposed upon the integrated output voltage of the oscillator whereby that voltage is intermittently increased when at low level and/or intermittently reduced when at high level. These checking pulses, whether of the voltage-increasing or the voltage-reducing kind, are integrated to provide an enabling signal allowing a controlled load to be energized or de-energized according to the mean value of the output voltage; an absence of the enabling signal indicates a malfunction.

Abstract: Electrical components of an electronic switching device, such as a motion sensor of a monitoring system, are mounted on a dielectric carrier film covering opposite surfaces of a flat non-conductive support. The several components, disposed on the outer surfaces of the carrier film, are electrically interconnected by leads in the form of conductor strips on the inner film surfaces. A coil constituting such a component is embedded in a ferrite pot which is pasted onto an extension of the film and has a central pin with an end insertable into an aperture in an edge of the flat support after that extension is bent around the edge. The surfaces of the support may be pitted to provide recesses for an adhesive designed to bond that support to the film.

Abstract: A contactless motion detector, including an oscillator sensitive to an approaching metallic element, includes an electronic switch such as a thyristor triggerable by an output signal from a demodulator comprising a storage capacitor which is alternately chargeable and dischargeable, preferably with constant current, during each cycle of a high-frequency voltage generated by the oscillator. The oscillator voltage is compared with a reference voltage by means of a differential amplifier causing the flow of a charging current into the capacitor when the oscillator voltage exceeds the reference voltage whereas a discharging current flows out of that capacitor in the opposite case. The reference voltage is so chosen that the capacitor charge rises in the course of a few cycles above a predetermined threshold when the oscillator voltage is high but remains below that threshold when it is low.