RU2528523C1 - Backed-up led traffic light - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: traffic light circuit further includes low potential drop diodes and backup LEDs. Each of N main LEDs of a LED array is further connected in parallel to a circuit which consists of series-connected low potential drop diode and backup LED. In case of breakdown of the junction of any of the main LEDs, current begins to flow through the backup LED and the low potential drop diode, thereby ensuring continuous flow of current through all LEDs of the LED array. Fully functional emission of the traffic light is therefore maintained in case of breakdown of one or more LEDs. The disclosed LED traffic light therefore improves reliability of the LED matrix and increases the distance from a control station to a controlled traffic light.

EFFECT: high reliability of the LED array and longer distance from a control station to a controlled traffic light.

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Description

The invention relates to regulatory, warning devices installed along the route of wagons, locomotives or trains or acting between them.

Known traffic light (Pat. 2207745 RF. LED traffic light / BS Sergeev, SA Shchigolev, VV Nagovitsyn. IPC 7 B61L 5/18. Publ. 06/27/2003. Bull. No. 18), including LED matrix consisting of N LEDs, transformers and transistors. The disadvantage of this device is the complexity and high cost.

Closest to the proposed technical solution is a traffic light (Yesunin V.I. Railway signaling devices on LEDs // Automation, communication, computer science. - 2002, No. 5. - P.19, Fig. 1), containing an LED matrix consisting of in series connected N LEDs, which is connected through a contact of the signal relay to a constant current source providing the required current through the LEDs.

The disadvantage of this traffic light is that when one of the LEDs in the serial circuit breaks, the entire serial circuit is turned off. This reduces the reliability of the traffic light, is the reason for the need to implement the LED matrix in the form of several parallel circuits from series-connected groups of LEDs, which does not allow to increase the supply voltage of the matrix, which is required when controlling the traffic light from the control station, located at a great distance from each other.

The aim of the invention is to increase the reliability of the LED matrix and increase the distance from the control station to a controlled traffic light.

This goal is achieved by the fact that diodes with a small voltage drop and backup LEDs are additionally introduced into the traffic light circuit.

The essence of the invention lies in the fact that in parallel with each of the main N LEDs of the LED matrix, an additional circuit is connected, consisting of a diode connected in series with a small direct voltage drop and a backup LED.

The figure shows a diagram of a redundant LED traffic light, including a current source 1, which is connected to the inputs of LED matrix 3 through contact 2 of the signal relay. LED matrix 3 consists of a series connection of the main LEDs 4.1, 4.2, ... 4.N. Parallel to each of these LEDs, circuits are additionally connected in series, consisting of redundant LEDs 5.1, 5.2, ... 5.N and diodes 6.1, 6.2, ... 6.N with a small direct voltage drop, which can be used, for example, Schottky diodes.

For the normal functioning of the redundant traffic light, the following inequality is required:

U _{St. main} <U _d + U _{St. cut} ,

where U _{St. main} - a direct voltage drop on each of the main LEDs 4.1, 4.2, ... 4.N;

U _d - a direct voltage drop on each of the diodes 6.1, 6.2, ... 6.N;

U _{St. cut} - a direct voltage drop on each of the backup LEDs 5.1, 5.2, ... 5.N.

The proposed redundant LED traffic light operates as follows.

In normal operation, when the contact 2 of the signal relay is closed, the main LEDs 4.1, 4.2, ... 4.N of the LED matrix 3 emit. The magnitude of the current flowing through them is formed by a constant current source 1. Moreover, since the sum of the voltage drop across each of redundant LEDs 5.1, 5.2, ... 5.N and diodes with a small direct voltage drop 6.1, 6.2, ... 6.N more than the voltage drop at each of the main LEDs 4.1, 4.2, ... 4.N, then the current in the backup LEDs 5.1,5.2, ... 5., N will be absent.

If a break occurs in one of the series-connected LEDs 4.1, 4.2, ... 4, N, the current will flow through the corresponding series-connected circuit 5.1, 5.2, ... 5.N and 6.1, 6.2, ... 6, N, which will cause the appearance of radiation from the corresponding backup LED . For example, if a break occurs in the main LED 4.2, then the increasing voltage drop will open a chain consisting of a diode 6.2 and a backup LED 5.2, which will begin to emit, compensating for the radiation function of the failed main LED 4.2.

Therefore, the breakdown of one or more of the main LEDs will not lead to a failure of the LED matrix 3 and will cause the total traffic light intensity to remain unchanged.

The use of a Schottky diode having a small direct voltage drop instead of a diode with a pn junction makes it possible to reduce the power consumed by the proposed redundant LED traffic light.

Thanks to the application of the proposed scheme, it becomes possible to significantly increase the number of matrix LEDs connected in series without reducing the reliability of traffic lights. This leads to the possibility of increasing the supply voltage of traffic lights, which allows to increase the distance from the control station to the traffic light.

At the same time, since the control line uses a constant supply current, the possibility of illumination of an improper indication of the traffic light is excluded, which occurs when the traffic light is supplied from an alternating voltage along long lines.

Thus, the proposed LED traffic light can improve the reliability of the LED matrix and increase the distance from the control station to the controlled traffic light.

Claims (1)

A redundant LED traffic light containing an LED matrix consisting of N main LEDs connected in series, a signal relay contact, a DC source, characterized in that in parallel with each of the main N LED matrix LEDs, an additional circuit consisting of a series-connected diode with a small direct voltage drop is connected and backup LED.