JPH0330960Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a display control circuit for a multi-path display that selectively displays one of a plurality of display contents according to a condition signal. be.

[Conventional technology]

Each route indicator is used for the purpose of indicating one of multiple routes on various traffic routes, and has multiple light emitting elements arranged according to the characters or symbols to display. The system is designed to selectively emit light from desired light-emitting elements to display a character or symbol, but if any light-emitting element other than the desired light-emitting element emits light, it will result in a false display and pose a danger to traffic control. , In order to prevent this, a display control circuit illustrated in FIG. 2 has conventionally been used.

That is, in FIG. 2, relays 1R and 2R are provided that respond to condition signals S ₁ and S ₂ that correspond to display conditions given from the outside, and a transformer T
and a power supply section using a rectifier REC.
This converts alternating current power AC into direct current power, and contacts 1 of relays 1R and 2R for diode matrix circuits DM ₁ and DM ₂ having diodes d ₁ to _{d 6} .
While applying the positive pole of the DC power supply through R ₁ and 2R ₁ , the light emitting diodes A to E are connected between the matrix circuits DM ₁ and DM ₂ and the negative pole of the DC power supply according to the display contents with a current limiting resistor. A check relay CR is connected between the recovery contact and the negative electrode of each contact 1R ₁ and 2R ₁ , and this contact CR ₁ is connected to each light emitting diode A to _{R 5} . E and resistors r ₁ to _{r 5} and the negative electrode.

The light-emitting diodes A to E are arranged as shown in Fig. 3, and the light-emitting diodes A, C, and E emit light in response to the condition signal _S1 , and the light-emitting diodes B and C emit light in response to the same signal _S2 . , D emits light, and in this example,
``〓'' or ``〓'' is displayed selectively.

Therefore, when the condition signal _S1 is given, the relay 1R operates, and the positive electrode is applied to the matrix circuit _DM1 according to the operation of the contact _1R1 , and the diode
Power is applied to the light emitting diodes A, C, and E via d ₁ , d ₃ , and d ₆ , causing them to emit light, and the condition signal is
If S ₂ is given, relay 2R operates and contact 2
According to the operation of _R1 , a positive electrode is applied to the matrix circuit _DM2 , and electricity is supplied to the light emitting diodes B to D through the diodes _d2 , _d4 , and _d5 , so that they emit light, so that the above-mentioned display is displayed individually. It is done.

However, when relay 1R or 2R operates,
If any of the diodes d ₁ to _{d 6} is short-circuited due to a fault, and especially if the diode d ₃ or d ₄ is short-circuited, the positive electrode wraps around and even the light-emitting diodes that should not emit light emit light. In this case, relay 1
Contact point 1R ₁ or 2 of the one under restoration in R, 2R
The relay CR is energized through the recovery contact _R2 , which responds by turning off the contact _CR1 , thereby de-energizing the light emitting diodes A to E and stopping the display for safety. ing.

In addition, the short circuit state of diodes d ₁ , d ₂ , d ₅ , d ₆ ,
When the diodes _d1 to _d6 are open, unnecessary light is not emitted and erroneous display occurs, and the relays 1R,
The failure of 2R results in inoperation and similarly does not result in an erroneous display.Since both are failures on the safe side, no particular checks are performed.

[Problem that the invention attempts to solve]

However, in the past, relays 1R and 2R and their contacts 1R ₁ and 2
_R1 , and as the number of display contents increases, the number of relays also increases, which requires man-hours to maintain and inspect, and also tends to cause poor contact, resulting in a problem of reduced reliability.

As a countermeasure for this, it is possible to use semiconductor devices such as photocouplers instead of relays, but it is unspecified whether these devices will be in an open state or a short-circuit state when a fault occurs, making them unstable in terms of safety. This results in the following problem.

[Means for solving problems]

This invention to solve the above-mentioned problem is to supply a voltage of opposite polarity to the diode matrix and the phototransistor side of the photocoupler during inspection.

[Effect]

Therefore, if the component is normal, no current will flow even if a voltage of opposite polarity is supplied, but if the component is short-circuited, current will flow and an abnormality will be reported.

〔Example〕

FIG. 1 is a circuit diagram showing an embodiment of this invention, in which a light emitting diode and a light emitting diode inserted in the forward direction through current limiting resistors R ₁ and R ₂ are connected to _the positive polarity condition signals S ₁ and S 2 . Photocouplers P ₁ and P ₂ consisting of light-receiving transistors are respectively provided as photoelectric coupling means in correspondence with the condition signals S ₁ and S ₂ , and photocouplers P ₁ and P 2 are provided on the emitter sides of the light-receiving transistors as outputs. ₂ , diode matrix circuits DM ₁ and DM ₂ are provided respectively, and these buses X ₁ and X ₂ are connected to photocouplers P ₁ and P ₂ respectively.
is connected to the emitter of the photodetector transistor.

Further, between the matrix circuits DM ₁ and DM ₂ and the main contact of the relay contact CR ₁₂ , there are light emitting diodes A to E used as light emitting elements and current limiting resistors r ₁ to
Each series circuit with r ₅ is connected according to the display contents corresponding to the condition signals S ₁ and S ₂ .

On the other hand, a relay CR is provided as a reference relay that responds to the positive reference signal Sc, and its main contacts CR ₁₁ are connected to the output sides of photocouplers P ₁ and P ₂ , and the operating contacts are connected to the positive terminal of the DC power supply. Contact CR ₁₁
Connect the main contacts to the light emitting diodes A to E, the operating contacts to the negative pole of the DC power supply, and the recovery contacts to the positive pole, and insert contact CR ₁₃ between diodes d ₂₁ and d ₂₂ and relay AR. , the main contact of this is the relay AR side, and the operating contact is the diode d ₂₁ ,
d ₂₂ side, and connect the recovery contact with the recovery contact of contact CR ₁₁ , while connecting diode d ₄₁ between diodes d ₂₁ and d ₂₂ and the main contact of contact CR ₁₂ ,
The diodes _d42 to _d46 are connected in parallel to each series circuit of the light emitting diodes A to E and the resistors _r1 to _r5 , and these are connected in order when supplying DC power of opposite polarity to the diodes d1 to d6. They are connected to each other as a polarity that corresponds to the direction. Further, the relay AR is used as an alarm relay, and this contact _AR1 is provided for sending an alarm signal AAL to the outside.

In addition, the matrix circuit DM ₁ , the diode of DM
d ₁ to _{d 6} , d ₂₁ , and d ₂₂ are connected in the forward direction when bus bars X ₁ and X ₂ are positive electrodes,
Diodes d ₁₁ and d ₁₂ for blocking reverse voltage supply are connected in parallel to the light-receiving transistors of the photocouplers P ₁ and P ₂ , respectively. In addition, the power supply section includes a transformer T and a rectifier REC, and light emitting diodes A to E are arranged as shown in FIG.

Therefore, when the signals S ₁ , S ₂ , and Sc are not applied, the contacts CR ₁₁ to _{CR 13} are in the process of being restored.
A voltage of opposite polarity is supplied to the diodes _d21 , _d22 , _d1 to _{d6 through the contact CR12 and the diodes d41 to d46 , and if} any of them is short-circuited,
The relay AR is energized via the diode d ₁₁ or d ₁₂ and the contacts CR ₁₁ and CR ₁₃ , and in response, an alarm signal AL is sent out.

Also, if only the reference signal Sc is given, the relay CR
_Contacts CR ₁₁ to _{CR 13} operate in response to _the response _of
If any of them is short-circuited due to a failure, relay AR responds via contact CR ₁₃ and sends out an alarm signal AL. Regarding the above, if each part is normal, the check signal Sc and condition signal S ₁ or S ₂
If these are applied at the same time, the light emitting diodes A, C, E or B to D will emit light accordingly.

In addition, at this time, the relay AR will also operate and the alarm signal will be activated.
AL will be sent, but you can ignore this.

In addition, a fuse F is inserted in the output of the DC power supply, and if a short circuit occurs in any of the diodes _d41 to _d46 , an overcurrent will flow in any of the above states, and the fuse F will melt. The display is now completely stopped.

Therefore, according to the configuration shown in FIG. 1, all diodes are checked, and complete safety can be achieved.

In addition, in Figure 1, even if the condition signal increases, only two relays, CR and AR, need to be used.
Since no more relays are required, the space for accommodating the relays is reduced, the number of maintenance and inspection steps are also reduced, and high reliability is achieved.

However, the configuration of matrix circuits DM ₁ and DM ₂ and the number of light emitting diodes A to E are indicated by
The decision can be made depending on the display content of the symbol, etc., and it is also possible to use a combination of other light-emitting elements and light-receiving elements instead of the photocouplers P ₁ and P ₂ . Various modifications are possible, such as not only an element may be used, but also a DC power supply or the like may be used, and a circuit breaker such as a no-fuse breaker may be used instead of a fuse.

[Effect of idea]

As explained above, this device has a circuit configuration that can check whether each circuit component is short-circuited or not, making it possible to display information without erroneous display, making it a safe device for traffic control. It has the effect of being able to provide

[Brief explanation of drawings]

Figure 1 is a circuit diagram showing an embodiment of this invention, Figure 2 is a circuit diagram showing an embodiment of this invention.
The figure is a circuit diagram of a conventional device, and FIG. 3 is a diagram showing the arrangement of light emitting diodes. S ₁ , S ₂ ... Condition signal, P ₁ , P ₂ ... Photocoupler (photoelectric coupling means), DM ₁ , DM ₂ ... Diode matrix circuit, A to E ... Light emitting diode (light emitting element), Sc... …Reference signal, CR…Relay (reference relay), AR…Relay (alarm relay),
CR ₁ , CR ₂ , CR ₁₁ ~ CR ₁₃ , AR ₁ ... Contact, d ₁ ~
d ₆ , d ₁₁ , d ₁₂ , d ₃₁ to d ₃₅ , d ₄₁ to d ₄₆ ... diode, ... positive electrode, ... negative electrode.

Claims (1)

[Claims for utility model registration] Interface circuit IF, switching circuit SW,
The interface circuit IF is composed of a display circuit ID and first and second matrix circuits DM ₁ and DM ₂ , and the input side of the interface circuit IF is connected to the condition signal input terminal S 1 and the common terminal (-), and the output side is connected to the condition signal input terminal S ₁ and the common terminal (-). The first optical coupling element P ₁ has a diode d ₁₁ connected in parallel in the opposite polarity direction, the input side is connected to the reference signal input terminal Sc and the common terminal (-), and the output side has the diode d ₁₂ connected in the opposite polarity direction. 2nd connected in parallel
The switching circuit _SW is a rectifier that generates a DC voltage.
Aram relay with REC and first contact AR ₁
AR and first, second and third contacts CR ₁₁ ,
Consisting of a reference relay CR having CR ₁₂ and CR ₁₃ , the positive side of the rectifier and the first contact of the reference relay
Operating contact of CR ₁₁ and second contact of reference relay
The recovery contact of CR ₁₂ is connected, the negative side of the rectifier and the operating contact of the second contact CR ₁₂ of the reference relay and one electrode of the Aram relay AR are connected,
The other electrode of the alarm relay and the main contact of the third contact CR ₁₃ of the verification relay are connected, and the recovery contact of the first contact CR ₁₁ of the verification relay and the recovery contact of the third contact CR ₁₃ of the verification relay are connected. , the main contact of the first contact of the reference relay is connected to the cathode side of diodes d ₁₁ and d ₁₂ connected in parallel to the optical coupling element, and the contact AR ₁ of the aram relay is connected to the aram signal terminal.
AL, the reference relay CR is connected between the reference signal input terminal Sc and the common terminal (-), and the first diode matrix has its bus line _X1 connected in parallel with the first optical coupling element _P1. In _{the second} diode matrix _, bus line _{X 2 is}
diode connected in parallel with the optocoupler P ₂ of
_The display _circuit is connected to _the anode side of light emitting diodes A, B, _C , _{D.
The light} emitting diode and _the resistor form _{a series body} . A bypass diode is connected in parallel with the series body in the opposite direction to the conduction direction of the light emitting diode, and the cathode side of each bypass diode is connected to the cathode of the corresponding display diode of the diode matrix, and the check diode The cathode side of the diode matrix is connected to the cathode side of the check diode of the diode matrix, and the anode side of the bypass diode connected in parallel with the check diode and the light emitting diode is connected in common and then connected to the main contact of the second contact of the check relay. A display control circuit for a multi-path display device, characterized in that the circuit is connected to a contact point.