RU217834U1 - Magnetic switching device - Google Patents

Abstract

The utility model relates to the field of electrical engineering and can be used for placement in a closed volume to connect a voltage source to an electrical load by closing contacts. The technical result consists in providing a magnetic switching device mounted on a printed circuit board. The magnetic switching device contains flexible current-conducting plates with flat permanent magnets fixed on them, between which there is a movable rectangular plate made of a dielectric material, and the flat permanent magnets are located relative to each other with opposite poles, the other ends of the flexible plates are fixed on the pads of the printed circuit board. 2 ill.

Description

The utility model relates to the field of electrical engineering and can be used for placement in a closed volume to connect a voltage source to an electrical load by closing contacts.

Known contact device type toggle switch [1]. The device includes a housing, fixed contacts, a switching lever and a permanent magnet. The permanent magnet is freely mounted on the switching lever, and the lever itself is fixed on the axis with the possibility of contact of the magnet with stops made of magnetic material mounted on the side walls of the housing. When the switching lever is turned, the contacts are closed and the lever is fixed due to the attraction of the magnet to the stop made of magnetic material. The disadvantages of such a contact device are: large dimensions that prevent the placement of the contact device on the surface of the printed circuit board, placed in a small closed volume; the presence of a shift lever, which also has significant dimensions.

A magnetic switching device [2] is known, containing a driving element and a driven element having magnetically attracting surfaces, the two elements move at an angle to each other so as to bring the magnetic surfaces into and out of contact with each other.

Disadvantages - large dimensions that do not allow mounting the device on a printed circuit board; a large number of details.

Known magnetic switching device [3] containing the first switching mechanism, equipped with a movable magnet connected to the contact jumper, and the second switching mechanism, equipped with a magnet, which is connected to the movable switching body. The magnets have the same polarity on the end surfaces facing each other, and between the magnets there is a decoupling plate made of ferromagnetic material, which is smaller than the end surfaces of the magnets facing each other. At the same time, the executive body is made with the possibility of influencing the switching body with a movement backlash. The technical result is the implementation of a reliable switching process from a certain switching state while maintaining, in the event of vibrations or relative movements between the individual elements of the desired switching state, for example, an electrical connection or indication. The disadvantages of such a switching device are large dimensions, which do not allow mounting the device on a printed circuit board; a large number of details. The device is mainly used in the automotive industry and is mounted in the car door.

Closest to the claimed solution is a magnetic contact device (magnetic switch) [4] - prototype, includes a flexible metal strip on the inside of the sealed shell, having the first and second ends. The first end makes electrical contact and passes through the wall of the sealed sheath, with the strip firmly secured by the sheath wall at the exit point, leaving the second end unsupported and having a magnetic sensing element attached. The first dipole magnet is connected to a flexible metal strip and is located inside a sealed shell intermediate between the first and second ends. The second and third dipole magnets are diametrically opposed and separated from each other, where each of the second and third dipole magnets is fixedly connected to the inner surface of the sealed shell. Two electrical terminals connected respectively to the second and third dipole magnets passing through the hermetic shell. The magnetic activating device in sliding engagement with the outer surface of the hermetic shell affects the movement of the magnetic contact by sliding into the first and second positions corresponding to the alignment of the second and third dipole magnets, creating an electrical circuit flowing from the flexible metal strip to one of the said two electrical leads.

The disadvantages of such a switching device are large dimensions, which do not allow mounting the device on a printed circuit board and the impossibility of placing the device in a closed volume without bringing out the closed volume of the switching lever.

The purpose of the utility model is to create a magnetic switching device mounted on a printed circuit board, placed in a closed small-sized volume, with a clear fixation of contacts.

The magnetic switching device consists of two thin flexible strips - plates of conductive material with a thin movable rectangular dielectric plate placed between them;

The other ends of the flexible conductive plates are fixed with pins on the pads of the printed circuit board, which are included in the switched electronic circuit. A thin movable dielectric plate is fixed with one of its ends, opposite to the location of the flat magnets, in a special rectangular case, provided with holes for fixing this case in the holes on the printed circuit board using thin metal or dielectric threads and equipped with a cord for pulling out the movable dielectric plate . A special rectangular case connected to a thin movable plate and fixed to the printed circuit board is a mechanism that makes it difficult to accidentally turn on the magnetic switching device. A description of the operation of the mechanism will be given below.

In FIG. 1 shows the proposed magnetic switching device. The magnetic switching device consists of flat magnets 1 attached to flexible conductive plates 2. It is possible to use thin conductive metal plates (copper, brass, bronze) coated at the points of contact with a layer of gold or silver, or from a thin foil dielectric. Plate 2 is soldered to pins 3, which, in turn, are soldered to contact pads 4 located on printed circuit board 5. A thin (0.1-0.5 mm) dielectric plate 6 is placed between flexible conductive plates 2, which is pressed against the conductive plates with the help of a force generated by magnets 1 facing each other with opposite poles. The movable dielectric plate 6 is fixed at one end in a rectangular case 7, placed on the printed circuit board 5 and attached to it with a thin thread 8 (made of metal, nylon, etc.). The diameter of the thin thread 8 is selected from the condition that the breaking force of the thread is 3-5 kg. This effort is quite sufficient from accidentally turning on the magnetic switching device. If the force value is less than 3 kg, unauthorized activation of the device is possible, and if the force value is greater than 5 kg, it may be difficult to turn on the device. The shape of the housing 7 in the form of a rectangle prevents undesirable rotation around the axis of the movable dielectric plate 6. A loop 9 is inserted into the grooves on the housing 7 to pull the movable dielectric plate 6. The magnetic switching device is located in the housing 10 (conditionally shown, the top cover is not shown).

The device works as follows. A certain force Q is applied to the loop 9 (see Fig. 1) (for example, 3-5 kg, which is set for a specific application of the device). This force is determined by the thickness and material of the thin retaining thread 8. The thread breaks, the plate 6 is pulled out and the conductive plates 2 are closed to each other.

Another variant of this magnetic switching device can be a device in which flat magnets attached to flexible conductive plates are parallel to the plane of the printed circuit board, and flexible conductive plates are soldered at one of the ends to contact pads located on the printed circuit board. In FIG. 2 shows this variant of the magnetic switching device. Here 1 - flat magnets, 2 - flexible conductive plates, 5 - printed circuit board, 6 - movable dielectric plate.

As an example, a small-sized magnetic switching device was made with plan dimensions of 9 mm×2.5 mm and a height of 3 mm (see Fig. 1). Used commercially available rectangular magnets 1 made of Nd-Fe-B material with dimensions of 3 mm x 3 mm x 1 mm. The pressing force of the magnets to each other was 400 g, which is quite sufficient to obtain a low-resistance electrical contact between the conductive plates 2. A nylon fishing line with a diameter of 0.2 mm was used as a holding thread 8 with a breaking force of 4.5 kg. When pulling out the dielectric plate 6 with a force of more than 4.5 kg, the thread 8 broke and the electrical contact between the conductive plates 2 occurred. Round magnets with a diameter of 1 mm and a thickness of 1 mm are also commercially available, on the basis of which it is possible to manufacture a small-sized contact device with even smaller dimensions, for example, 5 mm × 3 mm × 1 mm.

Other options for constructing a magnetic switching device are also possible, which are based on the essence of the solutions proposed above.

The technical result of using the proposed solution is that the magnetic switching device has small dimensions.

Information sources:

1. Patent RU2248636C2. CONTACT DEVICE. Published 03/20/2005. Bull. No. 8.

2. Patent US4296394A. MAGNETIC SWITCHING DEVICE FOR CONTACT-DEPENDENT AND CONTACTLESS SWITCHING. 1981-10-20.

3. Patent RU2450383C2. MAGNETIC SWITCHING DEVICE. Published May 10, 2012, Bull. No. 13.

4. Patent US6246307B1.MAGNETIC SWITCH. 2001-06-12.

Claims (1)

A magnetic switching device comprising flexible conductive plates with flat permanent magnets fixed on them, characterized in that between the flexible conductive plates there is a movable rectangular plate made of a dielectric material, and the flat permanent magnets are located relative to each other with opposite poles, and the others the ends of the flexible plates are fixed on the pads of the printed circuit board.

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