Siemens Aktiengesellschaft

Peter Drebinger

Heinrich Brunner

Walter Wimmer

Heinz Merkle

Peter Hoehne

Johann Hoisl

Guenter Kochanowski

A method and a circuit arrangement for determining the entry and/or exit of a vehicle into or out of a predetermined monitoring zone, which is defined by at least one inductive measuring loop whose change in inductance, which occurs as a result of the entry of a vehicle into the monitoring zone or the exit of a vehicle out of the monitoring zone, is used to control the oscillation frequency of an oscillator circuit is disclosed. In this method a measuring signal which corresponds to the oscillation frequency of the oscillator circuit and a reference signal which corresponds to a reference oscillation frequency are subtracted from one another. The difference signal thus formed is processed in an analysis device for display purposes. In order to achieve a relatively high degree of measuring accuracy, while employing circuit components which possess a relatively low operating frequency, it is provided that the measuring signal which corresponds to the oscillation frequency of the oscillator circuit is obtained and that on the occurrence of a first measuring pulse in a measuring pulse sequence derived from the oscillation signal of the oscillator circuit and with a reduced pulse rate, at the beginning of a measuring interval determined by a preselectable number of measuring pulses, a bistable trigger element is set to emit a specific output signal. On the occurrence of the output signal, which, for the duration of the selected measuring interval, counting pulses are counted with a pulse rate which is high in comparison to the pulse rate of the measuring pulses in a counting pulse counter whose counter signal, which is emitted at the end of the selected measuring interval, is made available as the measuring signal which corresponds to the oscillation frequency of the oscillator circuit.

Method and circuit arrangement for determining the entry and/or exit of

A traffic-dependently controllable signaling system utilizing the lengths of the time intervals between two successive vehicles for terminating the green light duration for the involved flow of traffic, in which each time interval is compared with a first, larger theoretical time limit value. If the first theoretical time limit value is reached, the green light signal for such traffic flow is terminated. In addition, all time gaps are compared with a second smaller theoretical time limit value and if this second theoretical time limit value is exceeded by two successive time intervals or at least two of a group of time intervals, the green light signal for the particular flow of traffic is likewise terminated.

Method and apparatus for calculating the green light time in

A circuit arrangement for monitoring the state of signal systems, particularly traffic light systems monitors different signal states as to the admissability or inadmissibility thereof in a simple manner without the necessity of carrying out manual wiring manipulations given a change of the signal conditions in adaptation to changed conditions or given an expansion of the signal system to be monitored. For this purpose, test signals which indicate test signal states are fixed in a memory and are processed with the signals indicating the respectively existing actual signal state of the signal transmitters in at least one microprocessor in such a manner that each signal indicating an actual state is compared with all test signals which are called up step-by-step in succession from the memory.

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Munich, Germany

Peter Drebinger