JP2936301B2 - Signal light disconnection detection device using light emitting diode - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting disconnection of a signal lamp using an LED element as a light emitting source.

[0002]

2. Description of the Related Art In recent years, LEDs (Light Emitl) have been developed.
ing Diode (Light Emitting Diode) has been developed as a high-brightness product and has been widely used as a light source for outdoor signal lights such as railway traffic signals, traffic signals, and level crossing alarms.

[0003] When an LED fails under the influence of a surge or the like, a disconnection failure (open failure) occurs more frequently than a short-circuit failure. When using an LED as a light source for a signal light,
A board is built in the lamp, and a plurality of LEDs are mounted on the board in a matrix. For example, a crossing warning light of a railway signal has 400 LEDs arranged side by side on a circular substrate. In this case, if all the LEDs are connected in series to the power supply circuit, and if one of them fails, all the LEDs go out, so ideally all the LEDs are connected in parallel to the power supply. Is preferred. However, practically, there are many examples in which about 8 to 10 LEDs are connected in series to form a series circuit of one unit, and two or more sets of the series circuits are connected in parallel to a power supply circuit.

[0004]

According to such a wiring structure, when one LED included in one unit of the serial circuit fails, all the LEDs included in one unit of the serial circuit are failed.
Although the ED is extinguished, in the above example, only 8 to 10 out of a total of 400 LEDs are extinguished, and most of them are turned on, so that the alarm flash has almost no effect. , 2
When more than one set of LEDs is extinguished, the luminance decreases as the number of extinguished sets increases, which hinders flashing.

However, when one or more sets of LEDs are extinguished, they appear as a pseudo-pattern on the lighting surface of the LED. However, in practice, the front of the LED is covered with a stepped lens. However, it is difficult to visually check whether at least a part of the set of LEDs has been extinguished from outside the lamp. However, when at least one set of the LED of the signal light is extinguished, repair is necessary, but at present, the disconnection of the LED of the signal light is not detected because the LED has excellent life characteristics. Is the actual situation. However, it is theoretically possible to constantly monitor the value of the current flowing through the set of LEDs and to perform disconnection detection using a detection signal of a change in the current value. However, actually, when the number of LED sets connected in parallel to the power supply circuit is large, about 1 to 2 sets of L
Even if the set of ED goes out, the current value changes little, so
It is difficult to detect the disconnection of the LED based on the change in the current value.

An object of the present invention is to provide an apparatus for detecting disconnection of a signal lamp using a light emitting diode which detects disconnection of an LED and outputs failure occurrence information.

[0007]

In order to achieve the above object, a disconnection detecting apparatus for a signal lamp using a light emitting diode according to the present invention comprises a set of a plurality of LEDs, a detecting element, and a detecting circuit. In the disconnection detection device, the plurality of LED sets are obtained by dividing a plurality of LEDs incorporated in a lamp as a light source of a signal lamp into two or more sets, and each LED set includes two or more LEDs. Are connected in series with each other, and are connected in parallel to the power supply circuit. The detecting element detects conduction of the series circuit of each set of LEDs for each set, and outputs a conduction detection signal to the detection circuit. , The sensing element is a photo coupler,
The input side was connected in series to the series circuit of each LED set
Connected in parallel with a resistor, the output side is connected in series and detected
An AND circuit for outputting to the circuit is formed, and the detection circuit conducts with the conduction detection signal output from each set of LEDs as an input, and when at least one of them is interrupted, LED failure occurrence information Is output.

The detection circuit has a photocoupler,
A relay is connected in series with the photocoupler, and the lifting contact of the relay is connected to the wiring of a monitoring circuit that connects the lighting device and the monitoring station, and the photocoupler is connected to a detection element of each LED set. In accordance with the AND condition of the output conduction detection signal, the contact point of the relay is lifted to conduct the monitoring circuit.

In addition, the display circuit has a display circuit, and the display circuit includes a display device, and the display device includes a signal lamp, an alarm device, and the like.
LED installed in an easy-to-see position and detected by the detection circuit
Is displayed by lighting or extinguishing the lamp.

[0010]

[0011]

[0012]

In the present invention, the signal light includes a signal light of a railway signal, a signal light of a traffic signal, a warning light of an alarm, and an indicator light of other security equipment. The current flowing through the series circuit of each set of LEDs is always detected by the detection element, and when the AND condition is satisfied with the detection signal output from each detection element, the detection circuit conducts with the output, and
The relay is energized. Excitation of the relay forms a lifting contact of the relay provided in the monitoring circuit, and monitoring information indicating that the signal light is normally lit is transmitted to the monitoring station.

On the other hand, when at least one of the LEDs is disconnected, if the current in the series circuit of the set of LEDs containing the disconnected LED is interrupted, the AND condition is broken, the relay is demagnetized, and the lifting contact of the relay is dropped. The fault occurrence information is transmitted to the monitoring station through the monitoring circuit, and the falling contact of the display circuit provided in the lamp falls, and the display turns on to display the fault occurrence information. When an indicator is provided in the detection circuit, the indicator is always turned on, and is turned off when a failure occurs to display failure occurrence information.

A photocoupler is suitable for the sensing element. The photocoupler is an electricity-to-light conversion element (light-emitting element)
And the light-to-electrical conversion element (light-receiving element) as a single system. The insulation between the input side and the output side is complete, and the influence between circuits and the influence from the output side to the input side are reduced. In addition, since there is no mechanical contact portion, noise, deterioration, wear and the like are less likely to occur. The output terminal of each photocoupler connected to the series circuit of each LED set forms an AND circuit, and the output signal of the photocoupler connected to the detection circuit operates to detect when the AND condition is broken. The circuit is disconnected and fault occurrence information is output.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a level crossing alarm to which the device of the present invention is applied. The level crossing alarm 1 is a device that predicts the approach of a train to a level crossing and warns the user to stop the traffic, and mainly includes a bell 2, a warning sign 3, a pair of warning lights 4, and a train direction indicator 5. It is provided on pillar 6. The warning light 4 is an LED as shown in FIG.
Is used as a light source and flashes 40 to 60 times per minute.

In FIG. 2, a lighting device 7 of the warning light 4 includes a board 1 on which a large number of LEDs 9, 9,.
0 is built in, and the opening edge of the light box 8 facing the front of the LED 9 is covered with a stepped lens 11.

The LED 9 is a light source of the warning light 4 and is mounted on the surface of the disk-shaped substrate 10 in a densely arranged longitudinally and laterally.

FIG. 3 shows a connection diagram of the power supply wiring of the LED 9. The embodiment is an example in which 400 LEDs 9 are mounted. The 400 LEDs 9 are connected in series 10 by 10 to connect a series circuit C _{1 to} C ₄₀ of 40 sets of LEDs 9 to a power supply (DC2
4V) in parallel. In the present invention, each L
A detection element 12 is further connected to each of the series circuits C _{1 to} C ₄₀ of the set of EDs, and a detection circuit 13 that is turned on by the output of each detection element 12 is incorporated.

The sensing element 12 is preferably a photocoupler. The photocoupler is an electricity-to-light conversion element (light-emitting element)
And a light-to-electric conversion element (light-receiving element) as one system, and a series circuit C ₁ -C _{40 of} each set of LEDs.
Has a photocoupler 1 with an electric-to-optical conversion element as the input side.
2 and connect each LED with the light-to-electrical conversion element as the output side.
Photocoupler 14 of the set of the output side of the photocoupler 12 connected to a series circuit C ₁ -C ₄₀ and connect in series to form an AND circuit, connected to its output to the detection circuit 13
Connect to the input side of. Photocoupler 14 of detection circuit 13
Is the A output from the photocoupler 12 of each LED set.
The ND condition is input to the detection circuit 13, and the electrical-to-optical conversion element is used on the input side, and the optical-to-electrical conversion element is used on the output side. Incidentally, the photo-coupler 12 of each of the series circuits C ₁ -C ₄₀ is connected in parallel with a resistor connected R in series with each of the series circuits.

The detection circuit 13 receives the AND condition outputs of the series circuits C _{1 to} C ₄₀ of each set of LEDs and outputs LED failure occurrence information to a monitoring station (not shown). The detection circuit 13 includes a relay 15 in series with the photocoupler 14.
Is connected, and a lifting contact 15a of a relay 15 is connected to a wiring of a monitoring circuit 16 connecting the lamp 7 and the monitoring station.

In the embodiment, when all the LEDs 9, 9,... Mounted on the substrate 10 are normally lit, a current flows through the series circuits C _{1 to} C ₄₀ of each set of LEDs, so that conduction detection is performed. The AND condition of the signal output is satisfied, the photocouplers of each set are turned on, the AND condition output is input to the photocoupler 14 of the detection circuit 13, and the photocoupler 14 of the detection circuit 13 is turned on to excite the relay 15. .

For this reason, the lifting contact 15a of the relay 15 is closed to make the monitoring circuit 16 conductive, and information indicating that all the flashes of the LEDs are normal is transmitted to the monitoring station.
When one of the LEDs 9, 9,..., For example, the second set of fourth LEDs 9 (2-4) is disconnected, a second set of series circuits including the LEDs 9 (2-4) is broken. It interrupted the current supply to the C _2, all included in the series circuit C ₂ of the second set LED9 (2-1), 9 (2-2 ), ..., 9 (2
-10) goes out, the output of the second set of photocouplers 12 (2) is turned off, the AND condition is broken, and the detection circuit 1
The output of the photocoupler 14 is "OFF", the relay 15 is demagnetized, the lifting contact 15a falls, and the monitoring circuit 16 is opened. The opening of the monitoring circuit 16 is detected at a monitoring station as failure occurrence information.

Not only when one LED is disconnected but also when two or more LEDs included in the same set are disconnected or when two or more LEDs included in different sets are disconnected simultaneously, All LEs in the set containing
As long as D is extinguished and the output of the photocoupler is turned off and the AND condition is broken, the failure occurrence information is transmitted to the monitoring station through the monitoring circuit 16. In the embodiment, even when one of the photocouplers 12 in each set fails openly, the failure occurrence information is transmitted to the monitoring station, but the LED of the set including the failed photocoupler 12 does not extinguish. , Does not hinder the signal display of the signal light.

FIG. 4 shows an example in which failure occurrence information is displayed on the lamp 7. In this example, the display circuit 1 is provided separately from the detection circuit 13.
7 is provided in parallel with the power supply circuit. The display circuit 17 is a series circuit of the display 18 and the falling contact 15b of the relay 15. A display 18 of the display circuit 17 is a display lamp for failure information, and uses an LED in the embodiment. The display 18 is installed facing the lower bottom of the light box 8 as shown in FIG.

According to the present embodiment, as long as the output of the photocoupler of each LED set as the detection element 12 satisfies the AND condition, the relay 15 is excited and the falling contact 15b is lifted. When the AND condition of the output of the photocoupler 12 of the set of LEDs is broken, the relay 15 is demagnetized, the falling contact 15b is dropped, the display circuit 17 is closed, and the display 1 is closed.
8 is turned on, and information on the occurrence of a failure is displayed on a part of the lamp 7. Of course, the lighting display of the failure occurrence information is not limited to the lamp, but may be of course provided at a pillar of an alarm device or other easily visible position.

Further, a display may be connected in place of the relay 15 of the detection circuit 13. In this case, each set of LEs
When the lighting of D is normal, the light is turned on, and when the AND condition of the conduction detection signal of each set of LEDs is broken, the light is turned off and fault occurrence information can be displayed.

In the above embodiment, the example in which the present invention is applied to the monitoring of the warning light of the level crossing alarm has been described. However, the present invention is not limited to this. The same can be applied to traffic lights and other security equipment indicator lights.

[0028]

As described above, according to the present invention, the LED used as the signal generation source is constantly monitored, and when at least one of the LEDs is turned off, failure occurrence information is output. In addition to monitoring failure occurrence information at a monitoring station, it is also possible to confirm on-site by turning on and displaying a lamp. The LED disconnection detecting element is not particularly limited as long as it monitors the continuity of the series circuit of the LED divided into two or more sets and outputs a signal when a failure occurs. By using a coupler, the input side L
A detection output can be obtained without affecting the ED series circuit, and high reliability can be obtained in the device.

According to the present invention, it is only necessary to monitor whether or not the series circuit of each set of LEDs is conductive by taking a conductive AND condition. Is output so that the occurrence of an abnormality can be captured at an early stage.

[Brief description of the drawings]

FIG. 1 is a diagram showing a railroad crossing alarm to which the device of the present invention is applied.

FIG. 2A is a partial cross-sectional front view of an alarm lamp, and FIG. 2B is a vertical cross-sectional side view of the same.

FIG. 3 is an electrical connection diagram showing one embodiment of the present invention.

FIG. 4 is an electrical connection diagram showing another embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 railroad crossing alarm 2 electric bell 3 beacon 4 warning light 5 train signal direction indicator 6 main pillar 7 lamp 8 light box 9 LED 10 board 11 stepped lens 12 detection element 13 detection circuit 14 photocoupler 15 relay 15a lifting contact 15b Drop contact 16 Monitoring circuit 17 Display circuit 18 Display

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ identification code FI G09G 3/14 G09G 3/14 N H02H 3/00 H02H 3/00 L (58) Fields surveyed (Int.Cl. ⁶ , DB G01R 31/02-31/07 B61L 1/00-29/32 G08B 1/00-9/20 G08G 1/00-9/02 G09G 3/00-3/19 H02H 1/00-3/07

Claims (3)

(57) [Claims] 1. An apparatus for detecting a disconnection of a signal light, comprising: a plurality of sets of LEDs; a detecting element; and a detection circuit, wherein the plurality of sets of LEDs include a plurality of LEDs incorporated in a lamp as a light source of the signal lights. The LED is divided into two or more sets. Each LED set is a series circuit in which two or more LEDs are connected in series, connected in parallel to a power supply circuit, and the detection element is The conduction of the series circuit is detected for each set, and the conduction detection signal is output to the detection circuit.The detection element is a photo coupler, and the input side of the photocoupler is connected to the series circuit of each LED set. straight
Connected in parallel with the resistor connected in the column, the output side is connected in series
To form an AND circuit that outputs to the detection circuit
Wherein the detection circuit conducts with the conduction detection signal output from each set of LEDs as an input, and outputs failure occurrence information of the LED when at least one of the detection circuits is interrupted. Signal lamp disconnection detection device using light emitting diodes. 2. The detection circuit has a photocoupler,
A relay is connected in series with the photocoupler, and the lifting contact of the relay is connected to the wiring of a monitoring circuit that connects the lamp and the monitoring station, and the photocoupler outputs from the detection element of each LED set. 2. The disconnection detection device for a signal lamp using a light emitting diode according to claim 1, wherein the monitoring circuit is conducted by lifting the contact of the relay in accordance with an AND condition of the conduction detection signal. 3. A display circuit, wherein the display circuit includes a display, and the display is a signal light, an alarm post, and the like.
The disconnection detecting device for a signal lamp using a light emitting diode according to claim 1, wherein the device is installed in a position and displays failure occurrence information of the LED detected by the detection circuit by lighting or extinguishing the light.