RU1820959C - Switching device built up of sealed-contact reed relays - Google Patents

Abstract

Usage: in the field of electrical engineering, and more specifically in limit switches, it is intended for switching DC actuating circuits by signals issued at the moment the controlled moving object reaches a predetermined position. The essence of the invention is that the limit switch contains the first 1 and second 2 terminals for connecting the load and the DC power source, the main and additional movable control elements, a housing with a non-magnetic flat section, transistor 6, resistor 7, first 8 and second 9 main reed switches and the first 11 and second 12 additional reed switches. Reed switches are connected in series in a closed circuit with outputs from the connections through two reed switches, one of which is connected to the collector of transistor 6 and to the first terminal 1 of the trip switch, and the other to the base of transistor 6. Resistor 7 is connected between -r-Tf-gt ; the database under the keys 3 3 and the inter-put option is flat on the start control panel. For example, in addition to the control panel, it is possible to control the switch or the half-element of the IS2% Xli) (Ј% () to I r; 2 by the base and emitter of the transistor 6 connected to the second terminal of the trip switch 2. The terminals of the load switch are connected to one of the terminals of the load 3 and the power source.The terminals of the load 3 and the power source, not connected to the terminals of the path switch, are interconnected. can be included in the circuit of the first 1 or second 2 conclusions of the limit switch. branched into a flat rectangular package and placed on the surface of a flat non-magnetic section facing the inside of the housing.The main control element moves along the contact part of the reed switches, causing them to simultaneously operate or release. The direction of movement of the additional control element is perpendicular to the contact details of 16 reed switches or the longitudinal axis of reed switch cylinders Moving an additional control element causes the reed switches to be triggered or released alternately. As the main and additional control elements, the main and additional movable permanent magnets or the main and additional movable blinds made of soft magnetic material can be used, respectively. An additional movable control element is used to monitor the health of the reed switches and the technical condition of the limit switch. 10 ill. i with hO O e eat Yu GJ fun.

Description

The invention relates to electrical engineering, and more particularly to limit switches, and is intended for switching DC actuating circuits by signals issued at the moment the controlled moving object reaches a predetermined position.

Figures 1 and 2 show alternate circuitry for a circuit breaker, characterized by interconnections between the load and power source and the terminals of the circuit breaker; Figures 3-7 show an embodiment of a trip switch in which a permanent movable magnet is used as a movable control element; in Fig. 3, a trip switch is shown, in cross section of which the placement of a package of reed switches, a transistor and a resistor is visible; figure 4 is a section aa of the travel switch in a plane parallel to the flat non-magnetic portion of the switch housing; Fig. 5 shows a device for moving a permanent magnet used in an additional movable control element; Fig. 6 is a section B-B of this device in the longitudinal plane, which shows the placement of the device on the tested limit switch; Fig. 7 shows a package of reed switches and a voltage diagram at the output of the limit switch depending on the position of the permanent magnet of the additional movable control element relative to the package of reed switches; Figs. 8-10 are an embodiment of a trip switch in which, movable shutters are used as a movable control element; on Fig and 9 - the relative position of the movable curtains and the travel switch on the types of switch, respectively, from the side and from the side of a flat non-magnetic section of the housing along which the reed switches are placed (view B); Fig. 10 shows a package of reed switches and a voltage diagram at the output of the limit switch depending on the position of the movable shutter of the additional movable control element relative to the package of reed switches.

The directional switch contains the first 1 and second 2 terminals for connecting the terminals of the load 3 and the DC power supply (not conventionally shown).

The directional switch also contains a main movable control element, which can be used as a main movable permanent magnet 4, housing 5. transistor 6, for example, of the type n-p-p, resistor 7. the first 8 and second 9 main reed switches. The first output of the first main reed switch 8 is connected to the first.

terminal 1 of the switch, the first terminal of resistor 7 is connected to the base of transistor 6, and the terminals of load 3 and the power source not connected to the terminals of the limit switch are interconnected.

In addition, the directional switch contains an additional movable control element, which can be used as an additional movable permanent magnet 10, and the first 11 and second 12 additional reed switches. The housing 5 contains a non-magnetic flat section 13. The main reed switches 8 and 9 and additional reed switches 11 and 12 are arranged parallel to each other in the form of a flat rectangular packet (or matrix) 14 located on the surface 15 of the flat non-magnetic section 13. facing the switch housing 5 .

0 Contact details 16 of the first 8 and second 9 main reed switches and the first 11 and second 12 additional reed switches are located along the direction of movement of the main magnet 4 and perpendicular to the direction

5 movements of the additional magnet 10.

The first output of the main reed switch 8, connected to the first output 1 of the switch, is connected to the collector of the transistor 6 and the first output of the first additional

0 reed switch 11. The second output of the first main reed switch 8 is connected to the output pin of the second additional reed switch 12, and the second output of the first additional reed switch 11 is connected to the first output of the second

5 of the main reed switch 9. The second terminals of the second additional reed switch 12 and the second main reed switch 9 are interconnected and connected to the base of the transistor 6. The second output of the resistor 7 is connected to the emitter of the transistor 6, which is connected to the second terminal 2 of the switch.

The first terminal of the load 3 is connected to the first terminal 1 of the limit switch (Fig. 1), and the second terminal of the load 3 is connected5 to the second terminal of the positive polarity of the power supply. The first terminal of the negative polarity of the power supply is connected to the second terminal 2 of the switch. Thus load 3

0 is connected in series with the circuit between the positive terminal of the power supply and the first terminal 1 of the limit switch.

Load connection is also possible.

5 3 in series with the circuit between the first negative terminal of the power supply and the second terminal 2 of the limit switch (Fig. 2). In this case, the second terminal of the load 3 is connected to the second terminal 2 of the limit switch, the second terminal is positive

the polarity of the power source is connected to the first terminal 1 of the switch, and the first terminal of the load 3 and the first terminal of the negative polarity of the power source are interconnected.

Between the gerkrn cylinders, as well as on the outside of the package 14 along the reed gadgets, shutters 17 made of ferromagnetic material are installed, which make it possible to concentrate the control magnetic flux in the desired direction. Each shutter 17 consists of two parts located on both sides of the working gap between the contact parts 16.

The housing 5 is in the form of a parallelepiped and is made, for example, of aluminum or non-magnetic alloys thereof. At a high speed of movement of the control magnet 4 to reduce the influence of the magnetic field of the eddy currents, the non-magnetic flat portion 13 of the housing 5 can be made of a non-conductive non-magnetic material, e.g. fiberglass.

The transistor 6, for example of type 2T506A, is equipped with a radiator 18, to which it is mounted through a thin electrical insulating strip 19 of mica, lavsan or fluoroplastic with a thickness of 0.03-0.06 mm.

The housing 5 is provided with a flange 20 to which the radiator 18 is mounted. The connections between the housing 5 and the flange 20, as well as between the flange 20 and the radiator 18, have low thermal resistance, therefore, the housing 5 and the flange 20, as well as the radiator 18, are used to remove heat emitted by transistor 6.

The insulating strip 19 provides electrical insulation between the electrode of transistor 6, whose potential has a heat sink surface of transistor 6 (collector is such an electrode for transistor 2T506A), and radiator 18 with minimal thermal resistance between them. A resistor 7 is also attached to the flange 20.

If necessary, a screen of ferromagnetic material is placed inside the housing 5 to protect the trip switch from the influence of external extraneous Magnetic fields (not shown conditionally). :

 The flange 20 has holes 21 for attaching a limit switch to the product, the movement of the elements of which is to be controlled. The terminals of the limit switch are made of flexible wire 22 and have a seal 23 when passing through the wall of the housing 5.

The volume inside the housing 5 is filled with a compound, which ensures the sealing of the limit switch.

Additional control magnet 5 10; It is used in monitoring the technical state of reed switches and the operability of the limit switch as a whole. An additional magnet 10 is placed on the device 24, containing the base 25,

0 guides 26 located along the base 25, a screw 27 and a strap 28 with a threaded hole, fixed on one side of the base 25. In the central part, the base 25 has a rectangular hole 29 corresponding to the dimensions of the switch housing 5 in section with a plane parallel to it flat non-magnetic section 13. To the back of the base 25 around the perimeter of the rectangular

.0 of the hole 29, a clip 30 is attached to which the housing 5 of the tested limit switch is placed. The height of the cage 30 is chosen so that its lower edge lies on the surface of the flange 20 of the housing 5

5 of the limit switch, and the plane of the outer surface of the non-magnetic portion 13 of the case 5 of the limit switch coincided with the plane of the surface 31 of the base 25 of the fixture 24 facing the additional magnet 10 or was below it to a depth of 0.2-0.5 mm. The device 24 is equipped with a reading device for reading information while monitoring the technical condition of the reed switches,

5 comprising a first plate 32 with a scale fastened along the base 25 of the device 26 and a second plate 33 with an arrow-shaped index mounted on the additional magnet 10. The additional magnet 10 is moved along the base 25 of the device 24 along the guides 26 with the screw 27 passing through a threaded hole in the bar 28. The tool 24 is manufactured

5 of non-magnetic materials. The reed switches are installed in package 14 as follows. The first main reed switch 8 is placed along one of the sides of the package 14, and then installed one after another

0 the first additional reed switch 11, the second additional reed switch 12 and the second main reed switch 9.

The direction of movement of the additional magnet 10 is perpendicular to the 5-beat-detail of 16 reed switches (or the longitudinal axis of the reed switch cylinders). The length of the additional magnet 1-0 or its size in the direction of movement is not less than the distance between the contact details 16 of the extreme reed switches of the package 14, i.e. between the contact details 16 of the first main reed switch 8 and the second main reed switch 9. which should ensure that all the reed switches operate in one of the positions of the additional magnet 10 when it moves along the base 25 of the device 24.

In the limit switch, MK-10-3 type micro-miniature reed switches are used.

The switching function implemented by the limit switch has the form

Y X8Xi2VX9Xn

where is Xe; Xg: Xn; Xi2 are input signals that determine the presence or absence of a magnetic field affecting the contact part of 16 reed switches.

When closing the contacts of the reed switches, i.e. in the presence of a control magnetic field, the value of the input signal is taken equal to a logical unit. Then the signal at transistor 6 is also equal to a logical unit, and the signal at the output of the limit switch is equal to logical zero. The load 3 connected in series in the circuit of the collector (Fig. 1) or emitter (Fig. 2) of the transistor b is turned on, because transistor 6 is open.

With closed contacts of the reed switches, the voltage drop in the power circuit of the transistor 6 between the terminals of the collector and emitter is close to the voltage between its base and emitter, the value of which does not exceed 0,. 8 V.

This is due to the low contact resistance of the reed contacts (less than 0.3 ohms). The current through the contacts of the reed switches in the proposed limit switch is 3 times less than the collector current of the transistor and, therefore, the load current 3, where / 3 is the static current gain of the transistor. ...

When the contacts of the reed switches are open, the base circuit of the transistor 6 is disconnected. The transistor 6 is closed and the load 3 is de-energized. The stabilization of the characteristics of the transistor 6 in this state is performed using a resistor 7 connected between the base and the emitter of the transistor. This reduces the influence of the reverse current of the collector jumper on the characteristics of the transistor 6 in the closed state.

When checking the technical condition of the reed switches, the additional magnet 1.0 moves from the initial position, in which the contacts of all the reed switches of the switch are open, in the direction from the first main reed switch 8 to the second main reed switch 9 located at the opposite edge of the reed switch package 14.

The value of the switching function depending on the magnitude of the input signals, i.e. the positions of the additional magnet 10, or rather, its front 34 and trailing edges 35, relative to the reed switches, are shown in the table.

Positions A and M correspond to the initial and final positions of the additional magnet 10. At position A, the additional magnet 10 is outside the package of reed switches 14 and its front edge 34 is located in front of the shutter 17 of the first main reed switch 8. At position M, the additional magnet 10 is also located behind the limits of the reed switch package 14 and its trailing edge 35 are located behind the shutter 17 of the second main reed switch 9. In positions B, C, D, D the leading edge 34

0 additional magnet 10 is sequentially mounted on the reed switches 8, 11, 12, 9, respectively, causing them to alternate operation. With the position of the additional magnet 10 in position D

5, its trailing edge 35 is located above the first main reed switch 8, the magnetic flux being sufficient to keep the contacts of the reed switch 8 closed. Further advancement of the additional magnet 10 in the positions E, F, K, L, M causes a successive release of the contacts of the reed switches 8, 11, 12, 9, respectively. when moving the trailing edge 35 of the additional magnet 10 in the area

5, between the contact parts 16 and the reed switch 17, the magnetic flux decreases to a release flux.

The switching function assumes values equal to zero, with the position of an additional magnet 10 in positions Г, Д,

B.; ..- ..,; .

Load 3 is on. This indicates the serviceability of the reed switches and the normal functioning of the 5 way switch.

The occurrence of any other signal combinations when moving the additional magnet 10 along the base 25 of the device 24 indicates the failure of one or more reed switches and a defect in the travel switch, and also allows to identify a failed reed switch if necessary. ...

The tool 24 allows 5 to control the technical condition of the reed switches and the travel switch during operation without removing the switch from the facility on which it is installed. When monitoring the technical condition of the reed switches And the trip switch parallel to the load 3. connected to the first terminal 1 of the switch (Fig. 1) or instead of it, an indicator 36 can be connected, containing, for example, an LED 37 and a ballast device 38, limiting the current through this diode. In this case, the first terminal of the ballast device 38 is connected to the cathode of the LED 37, and the anode of the LED 37 and the second terminal of the ballast device 38 are connected respectively to the positive terminal of the DC power source and the first terminal 1 of the limit switch.

When the load 3 is connected to the second terminal 2 of the limit switch (Fig. 2), the anode of the LED 37 is connected to the first terminal of the ballast device 38, and the cathode of the LED 37 and the second terminal of the ballast device 38 are connected respectively to the negative terminal of the power supply and the second terminal 2 of the limit switch.

Thus, the application of the proposed technical solution increases the suitability of the circuit breaker, making it possible to monitor its technical condition by contactless means.

The main magnet 4 is mounted on the surface of a mechanism (not conventionally shown), the movement of which is controlled. The front 39 and rear 40 edges of this magnet are perpendicular to the contact detail of 16 reed switches, i.e. perpendicular to the longitudinal axis of the reed switches, which ensures the simultaneous operation and release of all reed switches of the package 14 when controlled by the main magnet 4. The magnetization axis of the main magnet 4, as well as the additional magnet 10, is parallel to the longitudinal axis of the reed switches.

In the initial state, the main magnet 4 is removed from the working gap between the contact parts 16 of the reed switches and its magnetic flux through the contact parts 16 is insufficient for the reed switch to operate. As the main magnet 4 approaches, a part of its magnetic flux flows through the working gap between the contact parts 16, and when the level of response is reached, the reed switches close their contacts.

When the main magnet 4 is removed from the contacting portions of the contact parts 16, its magnetic flux through these portions decreases to the release flux at which the contact parts 16 open and the magnetic flux of this magnet begins to flow through only one contact part of each reed switch.

In the presence of an external magnetic field, the control of the slides of the limit switch can be carried out using movable shutters - the main 4 "and additional 42, which are part of the main, and additional 5 movable control elements. An external magnetic field can be created using, for example, a fixed permanent magnet 43, the opposite surface of the flat non-magnetic portion 0 to 13 of the trip switch housing 5 and mounted parallel to this surface to form a gap.

The main movable shutter 41 moves along the contact parts 16 of the reed switches in the gap between the fixed magnet 43 and the surface of the flat non-magnetic portion 13 of the trip switch housing 5, and the additional movable shutter 42 is perpendicular to the contact detail of the reed contacts in the same gap. The movable shutters 41 and 42 are made of soft magnet material. The magnetization axis of the fixed magnet 43 is directed parallel to the contact part of 16 reed switches. With the main 41 and additional 42 movable curtains removed from the gap, the contacts of the reed switches are closed, the transistor 6 is open, and the load 3 is turned on.

When moving the main curtain 41

0 along the contact details of 1 b reed switches, the magnetic circuit of the contact details of the reed switches is shunted.

When the main curtain overlaps 41 contact areas of the contact parts

5 16 reed switches, the magnetic flux between the contact parts 16 is reduced to a value at which the contacts of the reed contacts are almost simultaneously released, the transistor 6 is closed and the load 3 is turned off. When the main curtain 41 is removed from the gap between the fixed magnet 43 and the surface of the flat non-magnetic portion 13 of the trip switch housing 5, the magnetic flux increases through the working gap between the contact parts 16 of the reed switches and the contacts close again.

When checking the technical condition of the reed switches, the additional curtain 42 moves from the initial position, in which the contacts of all the reed switches are closed, in the direction from the first main reed switch 8 to the second main reed switch 9. located at the opposite

5 edges of a package of 14 reed switches.

In this case, the switching function takes values equal to unity at the position of the additional curtain 42 at positions D, E, E. Load 3 is turned on when the additional curtain 42 is located

these positions x. In other positions of the additional curtain 42, load 3 is turned off. Only such a cyclogram of the operation of the limit switch during the movement of the additional curtain 42 indicates the serviceability of the reed switches and the normal functioning of the limit switch. The length of the additional curtain 42 or its size in the direction of movement, as well as that of the additional magnet TO, is chosen not less than the distance between the contact details 16 of the extreme reed switches of the package 14, which should ensure that all reed switches operate in one of the positions of the additional curtain 42 ,;.: - -,

With the above choice of transistor 6, the limit switch provides switching of DC electrical circuits with voltage up to 36V and current up to 1A,

The proposed switch can also be used as a limit switch. In this regard, in the design of the trip switch for controlling the repcons, it is possible to use the movement of the main magnet 4 parallel to the package of 14 reed switches with the coincidence of the axis of symmetry in the vertical plane of the main magnet 4 and the package 14 of the reed switch (not shown conventionally).

The probability of fault-free operation of the limit switch can be determined by the formula:

P Pi P2Pz

where Pch, P2, Pz are the probabilities of failure-free operation of the reed switches 8,9,11,12, resistor 7 and transistor 6, respectively.

The probability of failure of the resistor 7 and transistor 6 in the circuit of the prototype and the associated limit switch can be taken equal. Then, an increase in the reliability of operation of the claimed limit switch can be achieved by increasing the probability of failure-free operation of the reed switches.

The probability of failure-free operation of the first 8 and second 9 main reed switches and the first 11 and second 12 additional reed switches is equal, i.e. P.- Pi2 P, the probability of failure-free operation of the reed switches of the prototype can be expressed as

P1p P2

and at the claimed limit switch, as

Nsh 2p2-p4

It is also admitted that the same type of reed switches MK-1Q-3 with

a resource of 5-10 operations, then in the presence of a minimum number of individual self-resolving failures (failures), for example five, the failure rate of one reed switch will be L 1 / srb.

The probability of failure-free operation of the reed switches of the prototype in this case, for example, over 10,000 operations, will be:

RSCH-0.9802,

and the claimed limit switch PT 0.9996.

The failure rate of the reed switches in the prototype circuits and the claimed limit switch under these conditions will be respectively

Box 1 / srb.

v6

 1 / srab and / 1sh 3.92.

The proposed directional switch also provides an increase in the probability of failure-free operation of the reed switches, which is achieved by reducing the influence of parameter changes during depressurization

a glass cylinder of reed switches and is calculated similarly to the above procedure, but the failure rate of the reed switches is determined by the time interval characterizing the time between the reed switch to fail (1 / h).

An increase in the reliability of operation of the claimed limit switch is also achieved by reducing the switching current in proportion to the gain of the transistor, i.e. 10-40 times, and for a composite transistor, 40-400 times. Thus, the proposed technical solution improves the operational characteristics of the track

circuit breaker by increasing the probability of failure-free operation of the reed switches and the testability of the circuit breaker by ensuring that its technical condition is monitored by contactless means.

Formulas a

A switching device on reed switches containing terminals intended for connection to a power supply, a load, power supply leads, a main control element mounted with the ability to move, a transistor, a resistor and two main reed switches, reed switches are installed in such a way that for each reed switch, the main control element moves parallel to the trajectory, the first output of the resistor is connected to the base of the transistor, which means that it is equipped with a housing and an additional pair of reed switches

and an additional control element, the housing is made with a section of non-magnetic material, the reed switches are located on the said section, each main and additional reed switch are connected in series with each other, these pairs of reed switches are installed parallel to each other, and the free leads of both pairs are also connected to each other , one of the common connection points is connected to one of the terminals intended for connection to the power source and to the collector of the transistor, the second common connection point of the pairs is connected to the first terminal odom rezy

a stator connected to the base of the transistor, the second terminal of which is connected to the emitter of the transistor and connected to the second terminal intended to be connected to the power source, the load is connected to one of the terminals intended to be connected to the power source and to the terminal of the power source, additional control the element is mounted relative to the housing in such a way that the longitudinal axis of each reed switch is perpendicular to the path of movement of the additional control element.

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Editor T. Ivanova

Order 2043 Mintage Subscription

VNIIIPI of the State Committee for Inventions and will be opened at I KNI USSR 113035. Moscow, Zh-35. Rauska nab., 4/5