RU2399957C1 - Light-emitting diode traffic light with cold state control - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: light-emitting diode traffic light with cold state control has a low-frequency alternating voltage source whose outputs are connected to the primary winding of a first transformer whose secondary winding is connected to the input of a bridge rectifier, the output of which is connected to inputs of an light-emitting diode matrix. The circuit of the light-emitting diode traffic light also includes a high-frequency alternating voltage source, second, third and fourth transformers, a capacitor, a high-pass filter, a high-frequency alternating voltage threshold amplifier, a control relay. Outputs of the high-frequency alternating voltage generator are connected to the primary winding of the second transformer. The secondary winding of the second transformer is connected between the first output of the secondary winding of the first transformer and the first input of the bridge rectifier. The second input of the bridge rectifier is connected through the primary winding of the third transformer to the second output of the secondary winding of the first transformer. The first and second leads of the capacitor are connected to the secondary winding of the first transformer and the light-emitting diode matrix is connected to outputs of the bridge rectifier. The secondary winding of the third transformer is connected to inputs of the high-pass filter whose outputs are connected to inputs of the high-frequency alternating voltage amplifier, the outputs of which are connected through the fourth transformer to inputs of the control relay.

EFFECT: controlled operation of light-emitting diodes of the light-emitting diode matrix of a traffic light in cold state.

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Description

The invention relates to the organization and management of traffic on railways and safety equipment in railway transport, namely to optical light signals - traffic lights.

Traffic lights are known in which an incandescent lamp is used as an emitter (Kotlyarenko N.F. et al. Track lock and auto-adjustment: Textbook for high schools. - M.: Transport, 1983. - P.192, Fig. 8.14). The disadvantage of such devices is the low reliability and the need for frequent replacement of lamps due to their burnout.

Traffic lights that use double-filament incandescent lamps (Deev AM et al. Resource-saving technologies in traffic control devices for indicators of traffic lights // have higher reliability) // Automation, Communications, Informatics. - 2000. - No. 1. - P.32, Fig. 1) . Their disadvantage is the low energy efficiency due to the significant power consumption from the power source.

The best energy characteristics are possessed by LED traffic lights, for which an LED matrix is used as a radiator, the power of which is supplied from a constant voltage source (Pat. RF No. 2237290. Three-digit LED traffic light / E.O. Saveliev, B. S. Sergeev. - Publ. 2004 Bull. No. 27).

Closest to the proposed technical solution is a LED traffic light powered by an alternating voltage network (Esyunin EI Railway signaling devices with LEDs // Automation, Communications, Informatics. - 2002. - No. 5. - P.20, Fig. 3) containing a transformer, the primary winding of which is switched by the contact of the signal relay and connected to the output of the low-frequency AC voltage source, and an LED matrix is connected to the secondary winding of the transformer through a bridge rectifier.

The disadvantage of this device is the inability to control the integrity of the matrix LEDs in the cold state, that is, in the absence of LED radiation due to disconnection of the matrix from the power source.

The aim of the invention is to monitor the integrity of the matrix LEDs in the cold state.

This goal is achieved by the fact that a high-frequency alternating voltage generator and a control relay are introduced into the LED traffic light circuit.

The essence of the invention lies in the fact that the high-frequency alternating voltage generator, the second, third and fourth transformers, a capacitor, a high-pass filter, a threshold high-frequency alternating voltage amplifier, a control relay are additionally introduced into the LED traffic light circuit, and the outputs of the high-frequency alternating voltage generator are connected to the primary winding of the second transformer, the secondary winding of the second transformer is connected between the first output of the secondary winding of the first trans the formator and the first input of the bridge rectifier, the second input of the bridge rectifier through the primary winding of the third transformer is connected to the second output of the secondary winding of the first transformer, the first and second terminals of the capacitor connected to the secondary winding of the first transformer, and the LED matrix is connected to the outputs of the bridge rectifier, the secondary winding of the third the transformer is connected to the inputs of the high-pass filter, the outputs connected to the inputs of the threshold amplifier of the high-frequency variable th voltage outputs are through the fourth transformer is connected to the control inputs of the relay.

The drawing shows a diagram of an LED traffic light with cold control. The cold-light LED traffic light contains a source of low-frequency AC voltage 1, connected through a signal relay 2 to the primary winding 3 of the first transformer 4. The outputs of the high-frequency AC voltage generator 5 are connected to the primary winding 6 of the second transformer 7, the secondary winding of which 8 is connected between the first output the secondary winding 9 of the first transformer 4 and the first input of the rectifier 10. The second input of the bridge rectifier 10 through the primary winding 11 of the third transfer the ormator is connected to the second output of the secondary winding 9 of the first transformer 4. The secondary winding 13 of the third transformer 12 is connected to the inputs of the high-pass filter, the outputs connected to the inputs of the threshold amplifier of the high-frequency AC voltage 15, and its outputs are connected to the primary winding 16 of the fourth transformer 17, to the secondary winding 18 of which a control relay 19 is connected. The first and second outputs of the secondary winding 9 of the first transformer are connected to the first and second terminals of the capacitor 20, and to the outputs of tovogo rectifier 10 connected to the LED array 21.

The proposed device operates as follows.

In the radiation state of the LED matrix 21, power is supplied to it from the AC voltage source 1 through the closed contact of the signal relay 2, the first transformer 4 and the bridge rectifier 10.

Since the aim of the invention is the implementation of the monitoring of the cold state of the LED matrix 21, then we consider the stage of operation of the LED traffic light circuit with the monitoring of the cold state when the power from the source of low-frequency AC voltage 1 is not supplied to the primary winding 3 of the first transformer 4. The output alternating voltage of the high-frequency generator 5 is supplied to the primary winding 6 of the second transformer 7. The secondary winding 9 of the first transformer 4 is shunted by the capacitor 20, therefore, the magnitude of the current flowing through the LED matrix 21 does not depend on the inductance of the secondary winding 9 of the first transformer 4. The magnitude of the current, flowing in a serial circuit including a capacitor 20, a primary winding 11 of the third transformer 12, a bridge rectifier 10 and an LED matrix 21, you are determined the output voltage of the high-frequency alternating voltage generator 5 and its internal resistance and is selected so that the current does not cause visible radiation of the LED matrix 21, that is, that the operating point is on the initial portion of the current-voltage characteristic of the LED matrix 21. The failure of the LED matrix 21, expressed by the failure of one or several LEDs, will lead to a change in the magnitude of the current flowing in the specified serial circuit, and, accordingly, to a change in the current in the primary winding 11 of the third tr ansformer 12. These changes cause changes in the alternating voltage at the secondary winding 13 of the third transformer 12. Through the high-pass filter 14, the alternating voltage is supplied to the threshold amplifier of the high-frequency alternating voltage 15, amplified by it and causes the on or off state of the control relay 19.

To realize the independence of the work of the LED traffic light with cold monitoring in the normal radiation modes of the LED matrix 21 and in the control mode when there is no radiation, the frequency of the alternating voltage of the high-frequency generator 5 should be much higher than the frequency of the alternating voltage of the source 1. This also determines the requirement of introducing a high-frequency filter 14. For the normal functioning of the circuit, it is necessary that the resonant frequency of the oscillatory circuit formed by the inductance w The original winding 9 of the first transformer 4 and the capacitor 20 was much higher than the frequency of the AC voltage source 1. At the same time, the capacitance of the capacitor 20 should be sufficiently small and not cause a significant change in the high-frequency current flowing through the above-mentioned series circuit.

Thus, the output voltage of the threshold high-frequency alternating voltage amplifier 15 will depend on the magnitude of the current flowing through the LED matrix 21, which, in turn, is determined by the integrity of the LEDs of this matrix.

Introduction to the circuit of the LED traffic light with the cold state control of the fourth transformer 17 ensures the fulfillment of the safety requirements for the functioning of the proposed device, since for any type of failure of the elements, for example in the high-frequency alternating voltage amplifier 15 or in the high-pass filter 14, the false switching on of the control relay 19 is excluded.

Therefore, the separation of the functions for monitoring the cold state of LEDs and the state of radiation, implemented using different frequencies of alternating voltage, allows us to identify the presence of LED failures in LED matrix 21. In practice, at a frequency of alternating voltage of source 1, usually equal to 50 Hz, it is sufficient to have the frequency of a high-frequency alternating voltage generator 5 not lower than 5 ÷ 10 kHz.

Therefore, the application of the proposed technical solution makes it possible to monitor the functioning of the LEDs of the LED matrix of the traffic light in the cold state.

Claims (1)

A cold-light LED traffic light containing a source of low-frequency AC voltage, the outputs of which are connected through the signal relay contact to the primary winding of the first transformer, the secondary winding of which is connected to the input of the bridge rectifier, the output of which is connected to the inputs of the LED matrix, characterized in that in the LED circuit an additional high-frequency alternating voltage generator, second, third and fourth transformers, a capacitor, high a total filter, a threshold high-frequency alternating voltage amplifier, a control relay, the outputs of the high-frequency alternating voltage generator being connected to the primary winding of the second transformer, the secondary winding of the second transformer connected between the first output of the secondary winding of the first transformer and the first input of the bridge rectifier, the second input of the bridge rectifier through the primary winding the third transformer is connected to the second output of the secondary winding of the first transformer, the first and the second terminals of the capacitor are connected to the secondary winding of the first transformer, and the LED matrix is connected to the outputs of the bridge rectifier, the secondary winding of the third transformer is connected to the inputs of the high-pass filter, the outputs connected to the inputs of the threshold high-frequency AC voltage amplifier, the outputs of which through the fourth transformer are connected to the inputs of the control relay .