CS272506B1 - Connection of timing circuit - Google Patents

Abstract

První'napěňový input (1) Yippee connected to common throw, where Yippee connected first end first resistor (5) and first end capacitor ( 8) , on second end first resistor (5) Yippee connected first end dru # hého resistor (6) and at the same time second stressed you input (2) second end the other rezisto # ru (6) Yippee connected on first end third resistor (7) and at the same time on input (10) hla # din circuit (9) second end third resistor (7) second end capacitor (8) and ženini outlet (12) level circuit (9) they are attached on common zemní vo # dič (13). Exit (11) level circuit (9) Yippee connected on exit (4) safe Timing circuit.

Description

The invention relates to the connection of a timing circuit with non-extending time intervals, meeting the requirements of security technology in railway transport.

The invention solves the problem of generating precise, safely non-extending time intervals, which are necessary for the timing of different sequences in railway signaling technology.

In the hitherto known connections of safe timing circuits in railway signaling technology, electromechanical relays are used in conjunction with electrolytic capacitors and resistors. Electromechanical relays designed for security technology are large, suffer from wear of mechanical parts, electrolytic capacitors are also large, have large capacity tolerances and are unstable over time. Higher voltage is required for longer time intervals. The time intervals created by these elements have considerable tolerances.

The above problems are solved by connecting a safe timing circuit according to the invention, characterized in that the first voltage input is connected to a common point where the first end of the first resistor and the first end of the capacitor are connected, the first end of the first resistor is connected to the second end of the first resistor; at the same time a second voltage input, the second end of the second resistor is connected to the first end of the third resistor and at the same time to the input of the level circuit, the second end of the third resistor, the second end of the capacitor and the ground terminal of the level circuit are connected to a common ground conductor. The output of the level circuit is connected to the output of a safe timing circuit.

The attached drawing shows an example of the connection of a safe timing circuit.

In a specific embodiment of the safe timing circuit, a Safe level sensor (hereinafter level circuit or HO) is used as an evaluator. The output voltage HO is only present if the input voltage is within a certain, preset tolerance band. The basis of the operation of capacitor-resistor timing circuits is the charging of the capacitor and its discharge through the resistor. Given the lower voltage limit at which the time interval and the constant discharge resistor end, then the length of the time interval is proportional to the magnitude of the voltage on the charged capacitor. If the capacitor is charged with a voltage that is not safe (this is not safely controlled by its increase), a safe time interval cannot be guaranteed.

The invention solves this problem by using the upper and lower limits of the tolerance band HO. The charging voltage for the longest time interval is connected to terminal 1. Resistors 5, 6, 7 form a divider with such a dividing ratio that the voltage at input HO 9 is just below the upper limit of the tolerance band HO. HO is then in an active state and its output 11 has a voltage. If the voltage increases on the capacitor 8 due to a fault (which would cause an extension of the time interval), the voltage at the HO input goes out of the tolerance band and there is no voltage at the HO output. After the voltage is disconnected from the voltage input 1, the time interval begins, the capacitor 8 is discharged through the resistors 5,6,7 until the voltage at the input HO falls below the lower limit of the tolerance band. The voltage at the HO output disappears and the time interval ends.

The charging voltage for a shorter time interval is connected to the input terminal 2 between the resistors 5, 6. The divider of the resistors 6, 7 has such a division ratio that the voltage at the input HO is again just below the upper limit of the tolerance band.

Capacitor 8 is charged via resistor 5. With this connection, the voltage for a shorter time interval is also controlled by the upper limit of the tolerance band HO 9. After disconnecting the voltage from terminal 2, the charged capacitor is discharged through resistors 5,6, 7 and at the moment of falling below the lower limit of tolerance. band HO, the voltage at the HO output disappears. In a similar way, by including additional resistors in the divider, other shorter time intervals can be achieved.

In the event of a failure of any element, the HO output voltage will be shorter than specified (meaning a shorter time interval) or the HO output voltage will not appear at all. ·

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CS 272506 Bl2

The safe timing circuit was used in the construction of the new train protection system and can be applied in other railway signaling equipment.

Claims (1)

Timing circuit connection, characterized in that the first voltage input (1) is connected to a common circuit, where the first end of the first resistor (5) and the first end of the capacitor (8) are connected, the first end is connected to the second end of the first resistor (5) a second resistor (6) and at the same time a second voltage input (2), the second end of the second resistor (6) is connected to the first end of the third resistor (7) and at the same time to the input (10) of the safe level circuit (9), the second end of the third resistor ( 7), the other end of the capacitor (8) and the ground terminal (12) of the level circuit (9) are connected to a common (ground) conductor (13) and the output (11) of the level circuit (9) is connected to the output (4) of the safe timing circuit. circuit.