Ifm Electronic Gmbh

Jean L Lamarche

Robert Buck

Johannes Burgel

The circuit arrangement has a plurality of comparators (3, 4, 5) and the measuring voltage on the one hand and different reference voltages on the other hand are present at the inputs (8, 9, 10, 11, 12, 13) of the comparators, and the outputs (14, 15, 16) of the comparators (3, 4, 5) contain the measurement signal. Less effort than that in accordance with the state of the art is required in that the reference voltage for the second comparator (4) is controllable with the aid of the output signal of the first comparator (3) and that the reference voltage for the third comparator (5) is controllable with the aid of the output signal of the second comparator (4), and that the measurement signal can be represented with the aid of the total of all output signals of all comparators (3, 4, 5).

Analog to digital converter with reference voltage control and analog

A contactless motion detector is energized in series with a load from a source of direct current via a pair of supply leads connected across a binary switching circuit in parallel with a voltage-generating network designed to deliver operating current to the detector in either switching position. The switching circuit comprises a main electronic switch, designed as a transistor, which is turned on or off by an output signal of the detector and in turn controls an ancillary electronic switch (transistor or thyristor) whose conduction intensifies the load current. When both electronic switches are transistors, they are interconnected in a positive-feedback loop driving them into conduction as soon as the main transistor is turned on; the base current of the ancillary transistor then contributes significantly to the load current while its collector current helps maintain the energization of the detector. The voltage-generating network includes a current limiter as well as a constant-voltage generator, e.g. a Zener diode.

Electronic monitoring system with direct-current power supply

A contactless motion detector is energized from a source of current via a pair of supply leads and delivers an output signal by way of a further lead through an Exclusive-OR gate to a control electrode of a binary electronic switch in circuit with the source and a load to modify the flow of load current upon the approach of a metallic element, for example. The Exclusive-OR gate, having one input connected to that further lead, has another input connected to an ancillary lead which in turn is connected to the other supply lead through a decoupling diode. A selector switch enables completion of the load circuit directly via the latter supply lead, thereby causing inverted transmission of the output signal of the detector to the control electrode, or by way of the ancillary lead to prevent the inversion of that output signal, whereby the load current can be either increased or reduced upon the occurrence of the event to be detected.

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Langenargen, Germany

Jean L Lamarche