SU654950A1 - Contact-free capacitive change-over switch - Google Patents

Description

capacitor plates, a conic spring is used, made with a cross section of a rectangular shape and with a horizontal pitch, a greater width of the wire, while the end of its largest turn is rigidly fixed on the printed plate and electrically connected to one of its electrically conductive sections, and the other electrically conducting section made in the form of a circle, the diameter of which is at least equal to the diameter of the greatest turn of the conical helical spring and is located with it sooono.

The drive element with a return spring at the point of attachment of the conical coil spring is rigidly connected to an additional round shape plate with an elastic coating on the surface painted around the comic helical spring and installed coaxially with it, while the diameter of this plate is at least equal to the diameter of the largest turn conical helical spring

On the inner surface of the upper part of the housing, there is also an additional ring-shaped electrode with a dielectric coating-, the outer diameter of which is at least equal to the diameter of an additional circular plate connected by a drive element and having an electrically conductive coating on the surface facing the said additional annular electrode connected with the smallest turn of the conical helical spring through the electrically conductive coating of the additional round plate STI1 yi.

FIG. 1 shows the switch in the initial position; in fig. 2 - the same in the pressed position; in fig. 3-5 are embodiments of the switch.

The contactless capacitive switch contains a housing 1 made of an electrically insulating mater, a drive element 2, rigidly connected with a button 3 and an upper turn of a conical helical spring 4, the lower turn of which is fixed to a printed circuit board 5 on which a wire is placed The following sections are 6, 7. The lower coil is the springs. 4 is electrically connected (for example, by soldering or welding) to section 6. Section 7 is in the form of an arc, the diameter of which is at least equal to two meters of a coil at the base of the spring. Dielectric strip 8 is placed on portion 7 of board 5.

The conical screw spring 4 is made of rectangular cross-section wire with a horizontal pitch that is wider than the width of the wire, for example, photochemically from a flat elastic plate and works in tension. The compression spring is made up of a spring of expansion, by the cause of its cone-shaped position.

The spring 4, irrespective of whether it works tension or compression, acts as a movable capacitor plate (structural capacitor). The production element 2 (see Fig. 3) is rigidly connected to the plate 9, made in the shape of a circle, whose diameter is equal to the diameter of the lower Blind of the spring 4, and having an elastic coating on the surface,

facing. 4.

According to another embodiment of the switch (see Fig. 4), an annular electrode 10 is placed on the inner noBepiX.HOCTH of the upper part of the housing 1

dielectric coated I. The outer diameter of the coated electrode is equal to the diameter of the plate 9, the outer surface of which has an electrically conductive coating 12 electrically connected

with a spring (verhnim turn). In this case, the plate 9 can be made entirely of electrically conductive material. In the embodiment shown in FIG. 5, spring 4 is stretching, return

The wiring element 2 is carried out

return spring returning power

which exceeds the force of the spring 4.

The switch works as follows.

When pressing the button 3 (see Fig. 1), which is rigidly connected with the drive element 2, the latter acts on the upper coil of the spring 4, which as a result of this effect, coil after coil on the dielectric strip 8, receives at the end compressing the form of a flat helical plate, which is a plate of a capacitor, the dielectric of which

is a gasket 8 (see Fig. 2). In this case, a capacitance is formed between the conductive portion 7 of the board 5 and the spring 4 in the form of a flat spiral plate. The change in capacitance from the stroke of the drive element 2 occurs smoothly and close to linear.

In order to guarantee the flat form of the spring 4 in the compressed position, the spring 4 is additionally pressed by the plate 9 with an elastic coating (see Fig. 3).

To eliminate the effect of parasitic coupling between the spring 4 and the conductive

in the off-state section 7 — as capacitor plates — the spring 4 is grounded through a constructive capacitance formed by an electrically conductive coating 12 of the plate 9 and an electrode 10 with a dielectric coating And (see Fig. 4).

The movable lining (spring 10), the area of which in the compressed state of the spring is equal to that of the lower fixed lining (section 7), forms

Claims (3)

it has a larger capacitance than in the known construction due to the series connection of capacitors. Claim 1. Non-contact capacitive switch comprising a body of electrically insulated material, a drive element with a return spring, rigidly connected with a button and connected to a spring of electrically conductive material acting as a moving plate of a co-noise TOpia, a printed circuit board with electrically conductive sections at least one of which serves as a fixed plate, a dielectric spacer placed between the movable and fixed plates, characterized in that, in order to increase reliability switching, as a spring, playing the role of a movable capacitor plate, a conical screw spring was used, made with a rectangular cross-section and horizontal pitch, greater than the width of the wire, while the end of its largest turn is rigidly fixed to the printed circuit board and electrically connected to one of the electrically conducting sections of the Board, and the other electrically conducting section is made in the shape of a circle, the diameter of which is at least equal to the diameter of the largest turn of the conical helical spring . 2. The switch according to claim 1, which is also distinguished by the fact that the drive element with a return spring at the point of attachment of the conical coil spring is rigidly connected to an additional round plate with an elastic coating on the surface facing the conical coil spring and installed coaxially with it the diameter of this plate is at least equal to the diameter of the largest turn of the conical screw spring. 3. Switch on PP. 1 and 2, characterized in that an annular electrode with a dielectric coating is additionally fixed on the inner surface of the upper part of the housing, the outer diameter of which is at least equal to the diameter of an additional circular plate rigidly connected to the drive element and having an electrically conductive coating on the surface, facing the said additional ring-shaped electrode associated with the smallest turn of the conical helical spring through the electrically conductive butt-covering of the additional round plate stina. Sources of information adopted during examination i: US Patent No. 3659163, H 01G 5/16, 1972. 2. Patent of Great Britain No. 1345799, 3. US patent No. 3693059, H 01G 5/16, 1972. WITH ПШ Д Ух-У УХХХХ55 P