RU2419160C1 - Device for controlling contact sensor - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: disclosed is a device for controlling a contact sensor, which has an electronic relay, first and second diodes, first and second resistors, first and second switches, an electronic switch, a line for communication with the controlled contact sensor, power buses, a stabilitron, the output of the device and first and second inputs of the device.

EFFECT: high reliability and broader functionalities of the device owing to separation of power circuit of the device and the relay blocking circuit.

2 cl, 3 dwg

Description

The invention relates to the field of electrical engineering, in particular to alarm systems that work under a certain condition, and can be used in various alarm systems to monitor the status of contact sensors.

A device for monitoring a contact sensor (see AS USSR No. 296133 of 09/18/1969, IPC: G08B 13/12, "Device for alarming", V.D. Bespalenko, published on 02/12/1971 , BI No. 8), containing a signal wire located on the guarded object, a thyristor and an alarm device connected in series with the thyristor, between the cathode and the control electrode of which a signal wire is connected stretched to the protected object, and the anode and the control electrode of the thyristor are connected between yourself through a resistor.

The disadvantages of the device are:

a) low functional reliability due to the direct connection of the semiconductor key element, that is, the thyristor, with the communication line, which is especially true for a long communication line between the device and the protected object, where interference from powerful pulsed electromagnetic fields is possible (for example, when switching the load of high-voltage lines power transmission lines, electrified railways, tram lines, during lightning discharges, etc.), which can lead to unstable operation of the device or its failure thyristor;

b) the lack of the ability to quickly verify operability without violating the integrity of the signal wire (or without opening the contacts of the sensor located on the guarded object and included in the break of the wired communication line).

The closest set of essential features to the claimed invention is a device for monitoring a contact sensor (see RF patent No. 2289163 dated 06/27/2005, IPC: G08B 13/08, 13/12 "Device for monitoring a contact sensor", R.F. .Zubaerov, G.I. Kramkov, A.S. Ioshkin, published on December 10, 2006, BI No. 34), containing an electromagnetic relay with a closing contact, the first and second diodes, a wired communication line with a gap for connecting the breaking contact of the aforementioned sensor, plus and minus power bus, switch, switch, first and second re zistors. The cathode of the first diode is connected to one end of the communication line, the other end of which is connected to the negative power bus and the first output of the relay winding through the NC contact of the switch. The second terminal of the relay winding is connected to the first terminal of the first resistor and the cathode of the second diode. The anode of the second diode is connected to the anode of the first diode and the first terminal of the second resistor. The second output of the first resistor is the first output of the device and is connected through the make contact of the electromagnetic relay to the second output of the second resistor connected through the make contact of the switch to the positive power bus. The closing contact of the switch is the second output of the device.

The disadvantages of this device are:

a) low functional reliability due to the presence of an electromagnetic relay; since when a device is exposed to powerful low-frequency or constant magnetic fields, malfunctions and false alarms of the relay, and therefore the device itself, will occur;

b) high current consumption of the device;

c) the inability to supply sensors in pulsed mode;

d) large mass and overall dimensions of the device due to the presence of magnetic screens.

These disadvantages of this device significantly limit its scope.

The task to be solved by the claimed device is aimed at creating a device for monitoring a contact sensor having higher functional reliability and significantly expanded functionality.

The technical result to which the invention is directed is to increase the functional reliability and expand the functionality of the device.

This technical result is achieved in that in a device for monitoring a contact sensor containing a relay with a make contact, a wired communication line with a gap for connecting a break contact of said sensor, plus and minus power buses, the first and second diodes, the cathode of the first of which is connected to one the end of the communication line, the other end of which is connected to the negative power bus through the NC contact of the first switch, the first and second resistors, the first terminal of the last of which is connected to the anodes of the first and the second diodes, the first output of the first resistor is the output of the device for monitoring the contact sensor, and the second output is connected to the cathode of the second diode, it is new that the second output of the first resistor is connected to the cathode of the second diode either directly or through an additional zener diode, the relay is made in the form of an electronic relay, a second switch and an electronic key are additionally introduced, the first and second inputs of which are the first and second inputs of the device for monitoring the contact sensor, and the first output d is connected to the positive power bus and the first relay output, the second output of which is connected to the first terminal of the first resistor, the second terminal of which is connected to the first relay input and through the make contact of the second switch with the second relay input, which is connected to the negative power bus, the second terminal of the second a resistor is connected to the second output of the electronic key.

The specified set of features allows to increase functional reliability and expand the functionality of the device. At the same time, the functional reliability of the device was improved due to the exclusion of the electromagnetic relay from its composition and the use of a relay made on the basis of more reliable elements operating under real-life conditions of the device (when exposed to powerful low-frequency or constant magnetic fields) - electronic relays, resistors and diodes (and Zener diode). The expansion of functional capabilities consists in providing new properties of the device: the ability to supply the device with both direct current from a DC power source and current pulses by separating the device’s power circuit and the relay blocking circuit when the device is powered through an electronic switch that provides at its output with the appropriate control both constant and pulse voltage, and the power supply to the interlock circuit is carried out directly from the DC power source, this reduces the current consumption of the device.

The reduction in size and weight of the device is achieved by eliminating the magnetic screens of the electromagnetic relay.

Figure 1 shows a diagram of a device for monitoring a contact sensor, figure 2, 3 are possible options for electrical circuits of an electronic relay and electronic key.

The device contains (see Fig. 1) electronic relay 1, first 2 and second 3 diodes, first 4 and second 5 resistors, first switch 6, electronic key 7, communication line 8, controlled contact sensor 9, negative power bus 10, zener diode 11, a second switch 12, an output 13 of the device for monitoring the contact sensor, a positive power bus 14, the first 15 and second 16 inputs of the device for monitoring the contact sensor.

The cathode of the diode 2 through the communication line 8, the NC contact of the sensor 9, included in the break line 8, and the NC contact of the switch 6 is connected to the second input of the electronic relay 1 and to the negative bus 10 of the power supply. The first input of the electronic relay 1 is connected to the second output of the first resistor 4 and directly or through the zener diode 11 with the cathode of the second diode 3, and the cathode of the zener diode 11 is connected to the cathode of the second diode 3, and the anode is connected to the second output of the first resistor 4. The second input of electronic relay 1 connected through the make contact of the second switch 12 to the first input of the electronic relay 1. The anode of the second diode 3 is connected to the anode of the first diode 2 and to the first output of the second resistor 5. The first output of the first resistor 4 is the output 13 of the device d To monitor the contact sensor and is connected to the second output of the electronic relay 1. The first output of the electronic relay 1 is connected to the plus power bus 14 and the first output of the electronic key 7, the second output of which is connected to the second output of the second resistor 5. The first and second inputs of the electronic key 7 are respectively, the first 15 and second 16 inputs of the device for monitoring the contact sensor.

The electronic relay 1 is designed to fix and remember the fact of the operation of the monitored contact sensor 9.

The first switch 6 is designed to simulate the fact of opening the NC contact of the sensor 9 during the operational check of the device. It can be implemented as a button with an NC contact (for example, type PKn 105-1), it can also be implemented on a toggle switch with the same contact group (for example, type PT8-1).

The electronic key 7 is designed to generate power pulses of the contact sensor 9.

The electronic relay (figure 2) is made on the chip 17 and the diode 18.

The electronic key (figure 3) is made on the integrated circuit 19 and the resistor 20.

Further, the operation of the device is considered with a zener diode 11 included in the circuit.

The device operates as follows.

In the initial state, the NC contacts of the switch 6 and the sensor 9 are closed, and the NC contact of the switch 12 is open. A positive DC voltage level is supplied to the first input 15 of the contact sensor control device (first input of the electronic key 7), and the second input 16 of the contact control device sensor - pulses of negative polarity. In this case, current pulses will flow through the LED of the microcircuit 19 of the electronic key 7, the amplitude of which is determined by the voltage supplied to the first input of the electronic key 7 and the resistor 20 of the electronic key 7, and is sufficient to trigger the electronic key 7. In this case, the first and second outputs are closed electronic key 7 for the duration of the pulse and, therefore, the appearance on the second output of positive pulses with an amplitude equal to the supply voltage of the device. From the positive power bus 14 to the negative power bus 10 through the closed first and second outputs of the electronic key 7, the resistor 5, diode 2, the closed contacts of the sensor 9 and the switch 6 flow current pulses, the amplitude of which is determined by the voltage of the device power supply and the resistance of the resistor 5. In this case the diode 3 and the electronic relay 1 connected in series are at a voltage equal to the direct voltage drop across the diode 2, and, therefore, the voltage at the first input of the electronic relay 1 relative to the second input is practically avnyaetsya zero. This means that the electronic relay 1 is in the off state, that is, the first and second outputs of the electronic relay 1 are open. The electronic relay 1 and the device remain in the described initial state.

When the sensor 9 is triggered, that is, when the contact opens, the current in the specified circuit stops and a current pulse begins to flow from the plus power bus 14 to the negative power bus 10 through the closed first and second outputs of the electronic switch 7, resistor 5, diode 3, zener diode 11 and the first and second inputs of the electronic relay 1 (via the LED of the microcircuit 17 and the diode 18 of the electronic relay). In this case, the amplitude of the current flowing through the LED of the electronic relay is sufficient to turn on this electronic relay 1. As a result, the first and second outputs of the electronic relay 1 are closed, and the output 13 of the device gives a signal about the operation of the monitored sensor 9 in the form of a DC voltage, and the electronic relay 1 becomes self-locking by the current flowing from the positive power bus 14 to the negative power bus 10 through the closed first and second outputs of the electronic relay 1, resistor 4 and LED, microcircuit 17 and diode 18 ele throne relay 1. Therefore, the signal at the output 13 of the device is subsequently saved, even if after that the initial state of the contact of the sensor 9 itself is restored or will be restored by maintenance personnel after eliminating the cause of the sensor 9. After restoring the closed state of the contact of the sensor 9 to put the device into control the state of the contact of the sensor 9, it is necessary to close at least for a short time the closing contact of the switch 12 (that is, turn on the corresponding toggle switch). In this case, the switch 12 by its closed contacts shunts the LED of the electronic relay 1 chip, the current through the above LED stops, the first and second outputs of the electronic relay 1 open, the electronic relay 1 turns off (removed from self-locking) and the signal from the output 13 of the device is removed. After restoring the initial state of the contacts of the switch 12 (turning off the corresponding toggle switch), the initial state of the device and monitoring the state of the contact of the sensor 9 are restored.

To control the operability of the device, it is enough to first open and close the contact of the switch 6 (press and release the corresponding button), then close and open the contact of the switch 12 (turn on and off the corresponding toggle switch). In this case, by opening the contact of the switch 6, the operation (opening of the contact) of the sensor 9 is simulated, so the device operates, as in the case of the operation of the sensor 9, and outputs an output signal to output 13. When the open contact of the switch 12 is closed, the device operates in the same way as when its initial state was restored after the sensor 9 was triggered, that is, the LED (first and second inputs) of the electronic relay 1 chip is shunted, then the electromagnetic relay 1 is turned off (removed from self-locking) and control of the state of the contact of the sensor 9 is restored.

The monitoring of the object on which the sensor 9 is located is performed by opening the first and second outputs of the electronic key 7 by stopping the supply of a constant voltage level to the first input 15 of the device or by stopping the supply of negative pulses to its second input 16, after which the current flow from the positive bus stops 14 power to the negative bus 10 power through the closed first and second outputs of the electronic key 7, the resistor 5, diode 2, the closed contact of the sensor 9 and switch 6 and it does not respond to a change in state the contact of the sensor 9. When resuming supply to the first input 15 of the device with a constant voltage level and the negative impulses arrive at its second input 16, the initial state of the device is restored, as in the cases considered, and thereby control over the state of the contact of the sensor 9 is restored.

The operation of the device in power mode from a constant current source is provided by supplying to the second 16 input of the device non-negative voltage pulses and a negative voltage level, while the device operates in the same way as described above for the pulse power mode.

It should be noted that when the device is operating in the pulsed power supply mode, the current consumption in the state monitoring mode of the sensor 9 will be less than in the power supply mode from the direct current source so many times as long as the repetition period is longer than the pulse duration. (In practice, the current consumption decreases ≈ 100 times.)

The zener diode 11 provides the ability to increase the noise immunity of the device with a long length of the communication line 8 by increasing the threshold of the electronic relay 1. The stabilization voltage of the zener diode 11 is selected based on the resistance of the communication line 8, the supply voltage of the device and the interference amplitude operating in the communication line 8.

The diode 18 of the electronic relay 1 is necessary when an electronic switch with a large voltage drop in the closed state (for example, a semiconductor transistor) will be used as a switch 12. The voltage drop on the key in this case is comparable to the voltage drop on the LED of the electronic relay 1 and to increase the reliability of shunting the first and second inputs of the electronic relay 1, the diode 18 is connected in series with the LED of the electronic relay 1.

In the case of direct connection of the second output of the resistor 4 with the cathode of the diode 3, the claimed technical result is also achieved.

In order to confirm the feasibility of the claimed object and the achieved technical result, a mock device for monitoring a contact sensor was assembled and tested, which was made on the basis of 249KP4BT type microcircuits, PKn105 buttons, 2D510A diodes, 2C210C zener diode and C3-33H resistors, with the length of the communication line with the sensor up to 10 km.

The tests of the layout showed the operability of the inventive device for monitoring a contact sensor and confirmed the achievement of the claimed technical result.

Claims (2)

1. A device for monitoring a contact sensor, comprising a relay with a make contact, a wired communication line with a gap for connecting the make contact of the sensor, plus and minus power buses, the first and second diodes, the cathode of the first of which is connected to one end of the communication line, the other end which through the NC contact of the first switch is connected to the negative power bus, the first and second resistors, the first terminal of the last of which is connected to the anodes of the first and second diodes, the first terminal of the first resistor is connected by the output of the device for monitoring the contact sensor, and the second output is connected to the cathode of the second diode, characterized in that the second output of the first resistor is connected to the cathode of the second diode either directly or through an additional zener diode, the relay is made in the form of an electronic relay, an additional second switch is additionally introduced and an electronic key, the first and second inputs of which are the first and second inputs of the device for monitoring the contact sensor, and the first output is connected to the positive power bus and the first output m relay, the second output of which is connected to a first terminal of a first resistor, a second terminal coupled to a first input of the relay and through normally open contact of the second switch with a second input of the relay, which is connected to the negative power bus and the second terminal of the second resistor connected to the second electronic key output. 2. The device for monitoring the contact sensor according to claim 1, characterized in that the zener diode cathode is connected to the cathode of the second diode, and the anode is connected to the second terminal of the first resistor.

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