JPH0573623B2 - - Google Patents

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention relates to a control circuit for a switch machine that is built into the switch machine and has a polarized relay that controls the operation of the switch machine. be.

"Prior art" Conventional control circuits for switch machines include, for example,
There is something like the one shown in Figure 2.

In other words, in the switch control circuit, the fail-safe output WLR from the safety output part of the control system of the railway signal safety device and the non-fail-safe outputs NR and RR from the general-purpose output part are connected to the corresponding DC The relays R1 to R3 are driven and, via the contact logic circuits of these DC relays, the polarized relay WR, which controls switching of the switch, is controlled.

The output WLR gives permission for switching control of the switch machine, and the outputs NR and RR give the switching direction. The output WLR operates until the point machine completes turning to a predetermined direction, and then returns to normal operation. The operating time of the output WLR is typically 5 to 6 seconds. With the output WLR recovery contact,
The coil of the polarized relay WR is short-circuited to prevent the polarized relay WR from operating incorrectly due to noise or cable contact.

When the polarized relay WR is energized in the forward direction (+→-), it forms a positioning contact and holds it; when it is energized in the reverse direction (-→+), it forms a reverse position contact and holds it. Retained.

"Problems to be Solved by the Invention" However, such conventional control circuits for switch machines have the following problems.

1 To control one point machine, DC relay R1 ~
Since three medium-sized relays of R3 are used, the control circuit becomes large and expensive.

2. Power consumption increases as the number of DC relays increases.

3. There is a risk of contact failure at the DC relay contacts.

The present invention has been made by focusing on such conventional problems, and it is possible to make the control circuit of a switch machine more compact and reduce costs.
It is an object of the present invention to provide a control circuit for a switch machine that solves the above problems by reducing power consumption and preventing poor contact.

"Means for Solving the Problems" The gist of the present invention for achieving this purpose is to: In a control circuit of a switch machine that has a built-in polarized relay WR that controls the operation of the switch machine, the power supply P is a DC power supply WLR with a voltage generated by the switch machine control permission signal. , and the DC power source EB whose voltage is not based on the control permission signal are logically summed.The polarized relay WR has its coil connected between a pair of parallel element circuits 1a and 1b, The circuits 1a and 1b are complementary circuits each connected to a power supply P and consisting of two semiconductor switch elements (Q1, Q2 and Q3, Q4) that operate complementary to the logic levels of the change direction command inputs RR and NR. It has complementary operating parts 2a and 2b, and current detection elements PC2 and PC4 are connected in series to complementary operating parts 2a and 2b, respectively, and the circuit breaker element NFB is configured to act as a polarized relay WR when the circuit is interrupted. Alarm contacts that conduct faster than the operating time
ALM is connected in series to parallel element circuits 1a and 1b, and the alarm contact ALM is a polarized relay WR.
It is connected in parallel to the coil.

It exists in the control circuit of a point machine.

"Function" However, the control circuit of the polarized relay has a voltage E
A power source is provided that is the logical sum of a DC power source of 1 and a current power source of EB (voltage of 1/2E or less).

When controlling a point machine from the opposite position side to the normal position side, the output from the control system applies an H level voltage to the complementary operating section on one side, and an L level voltage to the complementary operating section on the other side. is given.

One semiconductor switch device of one side of the complementary operating section is turned on and the other semiconductor switch device is turned off. Also, one semiconductor switch device of the complementary operation section on the other side is turned on, and the other semiconductor switch device is turned off. That is, the coil of the polarized relay is energized in the forward direction. The polarized relay constitutes a positioning contact, and the point machine is controlled to the positioning side.

A current sensing element connected to the complementary operating section on the other side detects the current flowing through the coil of the polarized relay.

After the switch has completed switching to the localization side, a bias current is applied to the polarized relay by the DC power supply EB, and the coil of the polarized relay continues to be energized in the forward direction.

When controlling a point machine from the normal position side to the reverse side, the output from the control system applies an L level voltage to the complementary operating section on one side and an H level voltage to the complementary operating section on the other side. Just give it.

If the semiconductor switch element has a conduction failure, the circuit interrupting element connected in series with the power supply of the control circuit will interrupt the control circuit earlier than the operating time of the polarized relay.
After disconnection, the alarm contact of the circuit breaker element short-circuits the coil of the polarized relay, thus preventing incorrect operation of the polarized relay WR.

“Embodiment” An embodiment of the present invention will be described below based on the drawings.

FIG. 1 shows a control circuit according to an embodiment of the present invention.

Between terminals A and G, a fail-safe DC power supply WLR of voltage E is applied from the control system. There is a voltage between terminal B and terminal G.
EB DC power is applied. However, the voltage value is set so that the polarized relay WR will not operate if the DC power supply EB is used alone.

The DC power supplies WLR and EB are connected to form a logical sum by diodes D3 and D4, and paired element circuits 1a and 1b are connected to these. Element circuits 1a and 1b have complementary operation sections 2a and 2b.

Terminal C is connected to a control system and is given an output NR for controlling the localization side.

Terminal D is also connected to the control system and is given an output RR for controlling the opposite side.

The outputs NR and RR are signals indicating the direction in which the switch should be controlled, and mean the N direction and the R direction, respectively.

An output RD for monitoring the operation of the control circuit is connected to the terminal E as an input of the control system.

An output ND for monitoring the operation of the control circuit is also connected to the terminal F as an input of the control system.

Outputs ND and RD are signals for monitoring the operating status of the control circuit.

The OV line of the 5V power supply is connected to terminal H.

Between the terminals I and J, the positive and negative poles of a coil of a polarized relay WR of a switch are connected in correspondence.

One complementary operation section 2a performs an operation complementary to the logic level of the input, and is composed of a PNP transistor Q1 and an NPN transistor Q2, which are semiconductor switch elements.

A photocoupler PC2, which is a current detection element that detects the presence or absence of current, is connected in series to the complementary operation section 2a.

Similarly, the other complementary operating section 2b consisting of a PNP transistor Q3 and an NPN transistor Q4 and a photocoupler PC4, which is a current detection element, are connected in series.

In this way, two element circuits 1a and 1b are configured in parallel.

A circuit breaker NFB, which is a circuit breaking element, is connected in series to the element circuits 1a and 1b configured in parallel.

The complementary operating parts are mutually connected to the coil of the polarized relay WR.

The alarm contact ALM of the circuit breaker NFB, which conducts when the circuit is cut off, is connected in parallel with the coil of the polarized relay WR.

Since the operating time of the polarized relay WR is nominally 65 ms, the circuit breaker NFB used has a characteristic that the breaking time is about 30 ms. The voltage E of the output WLR is set to 24V plus voltage drops due to diodes, transistors, photocouplers, etc.

Zener diodes ZD1, ZD2 and diode D5 are for absorbing reverse voltage by polarized relay WR. The Zener voltage value Z is set to satisfy EB<Z<E.

Next, the action will be explained.

When controlling a point machine from the reverse side to the normal position side, in Figure 1, a DC power supply WLR is applied between terminals A and G, and a DC power supply is applied between terminals B and G. EB is applied, an "H" level voltage is applied to terminal C, and an "L" level voltage is applied to terminal D.

PNP transistor Q1 that constitutes the switch,
NPN transistor Q4 turns on. NPN transistor Q2 and PNP transistor Q3 are turned off.

The coil of polarized relay WR is energized in the forward direction. Since the polarized relay WR constitutes a positioning contact, the point machine is controlled to the positioning side.

The direction of the current flowing through the coil of the polarized relay WR is detected by the photocoupler PC4. An "L" level voltage is output to terminal F and is given as an ND input to the control system.

On the other hand, no current flows through the photocoupler PC2.
An "H" level voltage is output to the terminal E and is given as an RD input to the control system.

After the point machine has completed switching to the stereotaxic side,
Output WLR disappears. The coil of the polarized relay WR continues to be energized in the forward direction by the DC power supply EB.

In the case of controlling the point machine from the normal position side to the reverse side, it can be considered in the same way as the above case, so the explanation will be omitted.

When PNP transistors Q3, Q1 and NPN transistors Q4, Q2 are fixed on the on side, excessive current flows in the control circuit, causing the circuit breaker to fail.
NFB operates on the blocking side. When the circuit current is interrupted, the coil of the polarized relay WR is short-circuited by the alarm contact ALM of the circuit breaker NFB. This prevents the polarized relay WR from malfunctioning.

It goes without saying that the point machine is equipped with a well-known operating mechanism.

"Effects of the Invention" According to the control circuit for a switch machine according to the present invention, the control circuit can be made compact and cost can be reduced, power consumption can be reduced, and contact failures can be prevented. be able to.

[Brief explanation of the drawing]

FIG. 1 shows a control circuit for a switch machine showing an embodiment of the present invention, and FIG. 2 shows a control circuit for a conventional switch machine. 1a, 1b...element circuit, 2a, 2b...complementary operation section, P...power supply, Q1, Q3...PNP transistor, Q2, Q4...NPN transistor,
PC1, PC2, PC3, PC4...Photocoupler, D
1-D5...Diode, ZD1, ZD2...Zener diode, R1-R4...Resistor, WR...
...Polarized relay, NFB...Circuit breaker, ALM...
Alarm contact.

Claims (1)

[Claims] 1. Comprising a power source P, a pair of element circuits 1a and 1b, a circuit breaking element NFB, and a polarized relay WR that is built into the switch machine and controls the operation of the switch machine. In the control circuit of the switch machine, the power supply P is a logical sum that combines a DC power supply WLR with a voltage generated by the switch machine control permission signal and a DC power supply EB with a voltage not generated by the control permission signal. The polarized relay WR has its coil connected between a pair of parallel element circuits 1a and 1b, each element circuit 1a and 1b is connected to a power source P, and receives a change direction command input RR. , NR has complementary operation parts 2a and 2b consisting of two semiconductor switch elements (Q1, Q2 and Q3, Q4) that perform complementary operations with respect to the logic levels of NR, and current detection elements PC2 and PC4 are complementary. It is connected in series to each of the operating parts 2a and 2b, and the circuit breaking element NFB is an alarm contact that becomes conductive earlier than the operating time of the polarized relay WR when the circuit is broken.
ALM is connected in series to parallel element circuits 1a and 1b, and the alarm contact ALM is a polarized relay WR.
A control circuit for a switch machine, which is connected in parallel to the coil.