CS246738B1 - Connection of a safe contactless monitoring and gate circuit - Google Patents

Abstract

The solution concerns the field of railway security technology. It solves the connection of a safe contactless monitoring and gating circuit, meeting the requirements of security technology in railway transport. The essence of the solution is the connection of a safe contactless monitoring and gating circuit characterized by the fact that the input of the monitoring circuit and the first input of the modulator are connected to the input terminal, the output of the monitoring circuit is connected to the second input of the modulator, the output of the modulator is connected to the output terminal. The solution can be used primarily in railway security technology and in those applications where it is required that in the event of a failure of the monitoring and gating circuit, no input signal is detected at the output of the circuit.

Description

The invention solves the connection of a safe contactless monitoring and gating circuit of electrical signals, satisfying the requirements of signaling technology in railway transport.

In the hitherto known circuits of safe supervision and gating circuits of electrical signals in railway signaling technology, electromechanical relays of special design or magnetic amplifiers that meet the safety requirements of signaling technology are used as gating elements. Gating elements solved on the principle of electromechanical elements suffer from mechanical wear, climatic effects, gating elements using magnetic amplifiers are heavy, bulky and during their production there are technological difficulties with the required small dispersion of values of electrical parameters. Supervisory and gating circuits with electromechanical elements as well as supervisory and gating circuits with magnetic amplifiers are difficult to reconcile with electronic circuits using semiconductor devices.

The above-mentioned difficulties are solved by the connection of a safe contactless monitoring and gating circuit according to the invention, characterized in that the input terminal is connected both to the input of the monitoring circuit and the first input of the modulator. output terminal.

The proposed arrangement achieves safe gating of the electrical signal deviating from the specified limits supervised by the supervisory circuit. At the same time, the entire circuit can be solved by contactless semiconductor elements without compromising railway safety.

Fig. 1 shows a wiring of a safe contactless monitoring and gating circuit according to the invention; Fig. 2 is an example of a practical implementation of a safe contactless monitoring and gating circuit.

In the particular embodiment of the secure contactless monitoring and gating circuit of FIG. 1, an input AC or pulse signal of known predetermined frequency is applied from input terminal 1 to input 2 of monitoring circuit 3 and to first input 8 of modulator 6. Output 4 of monitoring circuit 3 is The output 7 of the modulator 6 is connected to the output terminal 9. The output 4 of the supervisory circuit 3 generates a DC or AC signal only if the input AC or pulse signal applied to the input terminal 1 does not deviate from the specified tolerance. field. The supervisory circuit 3 is functionally designed to meet the requirements of the railway signaling technology, ie the considered failures of the supervisory circuit 3 result in a safe sense, the loss of the signal at the output 4 of the supervisory circuit 3. The signal applied from input terminal 1 to of the modulator 6 mixed with the signal fed from the output 4 of the supervisory circuit 3 to the second input 5 of the modulator 6. At the output 7 of the modulator 6 we receive a signal which can be expressed as:

U7 - K. U5. U8 (1) where

K is the modulator constant given by its design,

U7 is the instantaneous value of the signal at output 7 of the modulator 6, us is the instantaneous value of the signal applied to the second input 5 of the modulator 6, ue is the instantaneous value of the signal applied to the first input 8 of the modulator 6.

It follows from the relation (1j) that the loss of the signal at the second input 5 of the modulator 6 also results in the loss of the signal at the output 7 of the modulator 6 and at the output terminal 9. This arrangement fulfills the requirements of railway safety technology. at the output 4 of the monitoring circuit 3 deviates from the specified limits.

The connection of the safe contactless monitoring and gating circuit according to the invention can be used especially in the circuits for the safe control of the input signal frequency, when the monitoring circuit is realized by a safe frequency-voltage converter. In addition to the example above, the wiring can also be used in more complex wiring, such as a circuit for securely converting an AC input signal to another frequency band.

Claims (1)

Subject Connection of a safe contactless monitoring and gating circuit characterized in that the input terminal (1) is connected both to the input (2) of the monitoring circuit (3) and to the first input (8) of the modulator I / YNESS (6). (3) is connected to the second input (5) of the modulator (6), whose output (7) is connected to the output terminal (9).