Carbon film potentiometer

Abstract

The utility model discloses a carbon film potentiometer which is characterized in that a shell covers a base plate, a first through hole is formed in the shell, a rotating seat is arranged between the shell and the base plate, an electric brush sheet is sleeved at the bottom of the rotating seat, the electric brush sheet and the rotating seat can synchronously rotate, and the shell is provided with a first through hole. A contact is arranged at the bottom of the electric brush sheet, a terminal assembly is mounted in the substrate, and the electric brush sheet is characterized in that the terminal assembly is wrapped in the substrate, a carbon film resistor body is printed on the surface of the substrate, the contact is in contact with the carbon film resistor body, and the carbon film resistor body and the terminal assembly form surface contact at the top of the substrate. The problem that in the prior art, due to the fact that the carbon film resistor body is too thin, the carbon film resistor body sheet is prone to rivet deformation and rivet crack after the terminal is riveted, and consequently signal output is unstable is solved, and the stability of signal transmission is greatly improved.

Description

Technical Field

[0001] The utility model relates to a potentiometer, and more specifically to a carbon film potentiometer. Background Art

[0002] A carbon film potentiometer is made by coating a layer of carbon film on a horseshoe-shaped paper adhesive board. The relationship between its resistance value change and the position of the middle contact has three types: linear type, logarithmic type and exponential type. There are several types of carbon film potentiometers, including large-sized, small-sized and micro-sized ones, and some are combined with switches to form potentiometers with switches.

[0003] The utility model patent with the publication number CN219286130 discloses a rotary potentiometer, which is essentially a carbon film potentiometer. The rear ends of its first terminal, second terminal and third terminal are respectively fixed to the front end of the substrate by rivets.

[0004] The first terminal and the third terminal are respectively electrically connected to both ends of the carbon film resistor body, the second terminal is electrically connected to the conductive ring, and the front ends of the first terminal, the second terminal and the third terminal respectively extend out of the outer peripheral wall of the first housing (paragraph 0027 of the specification). First, the terminal assembly in the above technology is only fixed to the front end of the substrate by rivets. However, due to the too thin carbon film resistor sheet, the carbon film resistor sheet is easily deformed and cracked after the terminal assembly is riveted, resulting in unstable signal output. Secondly, since the rotating seat for fixing the brush sheet has a small bearing capacity, when it is extruded by an external force, the distance between the rotating seat and the substrate will be compressed, causing the brush sheet to deform or its height to be severely depressed in the housing, and there are quality hidden dangers for customers during use. Content of the Utility Model

[0005] To solve the above problems, the utility model provides a carbon film potentiometer, which includes a housing and a substrate. The housing covers the substrate. A first through hole is opened on the housing. A rotating seat is installed between the housing and the substrate. A brush sheet is sleeved at the bottom of the rotating seat. The brush sheet can rotate synchronously with the rotating seat. A contact is arranged at the bottom of the brush sheet. A terminal assembly is also installed inside the substrate. The terminal assembly is wrapped inside the substrate. A carbon film resistor body is printed on the surface of the substrate. The contact contacts the carbon film resistor body. The carbon film resistor body and the terminal assembly form a surface contact on the top of the substrate.

[0006] Furthermore, the terminal assembly includes a first terminal, a second terminal and a third terminal. A through groove is arranged on the side wall of the substrate. When the first terminal, the second terminal and the third terminal are arranged inside the substrate, the first terminal, the second terminal and the third terminal extend out of the substrate through the through groove.

[0007] Furthermore, the first terminal and the third terminal include a welding portion and a connecting portion. The welding portion extends outside the substrate through a through groove, and the connecting portion is disposed inside the substrate and forms a surface contact with the carbon film resistor printed on the top of the substrate.

[0008] Furthermore, a clamping portion is provided at one end of the connecting portion, and a clamping groove is provided on the side wall of the substrate. When the first terminal and the third terminal are wrapped inside the substrate, the clamping portion is clamped in the clamping groove.

[0009] Furthermore, a limiting portion is provided at the other end of the connecting portion, and the height of the limiting portion is higher than the height of the substrate.

[0010] Furthermore, the second terminal includes a welding portion and a conductive portion. The welding portion extends outside the substrate through a through groove, and the conductive portion is disposed inside the substrate and forms an electrical connection by making contact with a contact on the top of the substrate.

[0011] Furthermore, the shape of the conductive portion is annular, and an annular groove matching the shape of the conductive portion is provided on the top of the substrate.

[0012] Furthermore, a convex block is provided at the bottom of the rotating seat, and a limiting hole corresponding to the position of the convex block is provided on the brush piece.

[0013] Furthermore, a second through hole is provided on the substrate, and the position of the second through hole corresponds to the position of the first through hole. There is a support step at the bottom of the rotating seat. When the rotating seat is inserted into the second through hole, the support step is stuck on the edge of the second through hole.

[0014] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0015] 1. Compared with the prior art, in the present application, the terminal assembly is encapsulated inside the substrate, and then the carbon film resistor is printed on the top of the substrate, so that the terminal assembly forms a surface contact with the carbon film resistor, avoiding the problem in the prior art that due to the too thin carbon film resistor, the carbon film resistor piece is easily deformed and cracked after riveting the terminal, resulting in unstable signal output, thereby greatly improving the stability of signal transmission.

[0016] 2. When an axial external force is applied to the rotating seat, the support step will form a support between the rotating seat and the substrate, preventing the distance between the rotating seat and the substrate from being compressed, thereby enhancing the bearing capacity of the rotating seat, protecting the brush piece from being deformed by external extrusion, and eliminating quality hazards.

[0017] The additional aspects and advantages of the present utility model will be given in the following description part, and some will become obvious from the following description, or will be understood through the practice of the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0019] Figure 1 is an exploded view of the overall structure of the carbon film potentiometer of the present invention;

[0020] Figure 2 is a schematic structural diagram of the substrate and terminal assembly of the carbon film potentiometer of the present invention;

[0021] Figure 3 is a schematic structural diagram of the terminal assembly of the carbon film potentiometer of the present invention;

[0022] Figure 4 is a schematic structural diagram of the brush piece of the carbon film potentiometer of the present invention;

[0023] Figure 5 is a schematic structural diagram of the rotating seat of the carbon film potentiometer of the present invention.

[0024] The reference numerals and names in the drawings are as follows:

[0025] housing 100, substrate 200, first through hole 110, rotating seat 300, brush piece 400, contact 410, terminal assembly 500, carbon film resistor body 210, first terminal 510, second terminal 520, third terminal 530, through groove 220, welding part 511, connecting part 512, clamping part 513, clamping groove 230, limiting part 514, conductive part 522, annular groove 240, convex block 310, limiting hole 420, second through hole 250, supporting step 320. Detailed Embodiments

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0027] Now, in combination with the drawings, a further description of the preferred embodiments of the present invention will be given, as Figure 1As shown in the figure, the present utility model provides a carbon film potentiometer, which includes a housing 100 and a substrate 200. The housing 100 covers the substrate 200. A first through hole 110 is provided on the housing 100 for passing through a central axis (not shown in the figure). A rotating seat 300 is installed between the housing 100 and the substrate 200. The rotating seat 300 can rotate within the housing 100 under the drive of the central axis. A brush piece 400 is sleeved at the bottom of the rotating seat 300. The brush piece 400 can rotate synchronously with the rotating seat 300. A contact 410 is provided at the bottom of the brush piece 400. A terminal assembly 500 is also installed inside the substrate 200. The terminal assembly 500 is wrapped inside the substrate 200. Here, the so-called wrapping means that the terminal assembly 500 can be wrapped inside the substrate 200 by using a plastic coating process. A carbon film resistor body 210 is printed on the surface of the substrate 200. The contact 410 contacts the carbon film resistor body 210. The carbon film resistor body 210 and the terminal assembly 500 form a surface contact on the top of the substrate 200 to achieve electrical conduction. Compared with the prior art, in this application, the terminal assembly 500 is plastic-coated inside the substrate 200, and then the carbon film resistor body 210 is printed on the top of the substrate 200, so that the terminal assembly 500 and the carbon film resistor body 210 form a surface contact, avoiding the problems in the prior art that due to the carbon film resistor body 210 being too thin, the carbon film resistor body 210 sheet is easily deformed and cracked after terminal riveting, resulting in unstable signal output, thereby greatly improving the stability of signal transmission.

[0028] Furthermore, on the basis of the above-mentioned embodiment, in combination with Figure 1 and Figure 2 As shown in the figure, the terminal assembly 500 includes a first terminal 510, a second terminal 520 and a third terminal 530. A through groove 220 is provided on the side wall of the substrate 200. When the first terminal 510, the second terminal 520 and the third terminal 530 are arranged inside the substrate 200, the first terminal 510, the second terminal 520 and the third terminal 530 extend out of the substrate 200 through the through groove 220, which is convenient for welding between the first terminal 510, the second terminal 520 and the third terminal 530 and an external circuit board.

[0029] Furthermore, on the basis of the above-mentioned embodiment, in combination with Figure 1 and Figure 2As shown, the first terminal 510 and the third terminal 530 include a welding portion 511 and a connecting portion 512. The welding portion 511 extends outside the substrate 200 through the through slot 220 for connection with an external circuit board. The connecting portion 512 is disposed inside the substrate 200 and forms a surface contact with the carbon film resistor body 210 printed on the top of the substrate 200. In this way, when the brush piece 400 rotates driven by the central axis, the contact 410 is in electrical connection with the first terminal 510 and the third terminal 530 by contacting the carbon film resistor body 210.

[0030] Preferably, in combination with Figure 1 and Figure 2 As shown, a clamping portion 513 is provided at one end of the connecting portion 512, and a clamping groove 230 is provided on the side wall of the substrate 200. When the first terminal 510 and the third terminal 530 are wrapped inside the substrate 200, the clamping portion 513 is clamped in the clamping groove 230, thereby further enhancing the stability of the connection between the first terminal 510 and the third terminal 530 and the substrate 200, so that when riveting, the first terminal 510 and the third terminal 530 are less likely to fall off the substrate 200.

[0031] On the basis of the above embodiment, further preferably, in combination with Figure 1 and Figure 2 As shown, a limiting portion 514 is provided at the other end of the connecting portion 512. The height of the limiting portion 514 is higher than the height of the substrate 200, and a protrusion relative to the surface of the substrate 200 can be formed. In this way, when the brush piece 400 rotates driven by the central axis, it can limit the movement range of the contact 410.

[0032] Furthermore, on the basis of the above embodiment, in combination with Figure 1 and Figure 2 As shown, the second terminal 520 includes a welding portion 511 and a conductive portion 522. The welding portion 511 extends outside the substrate 200 through the through slot 220 for connection with an external circuit board. The conductive portion 522 is disposed inside the substrate 200 and forms an electrical connection by contacting the contact 410 on the top of the substrate 200, so as to form an electrical loop in cooperation with the first terminal 510 and the third terminal 530.

[0033] The shape of the conductive portion 522 is annular. In combination with Figure 1 and Figure 2As shown, a ring groove 240 matching the shape of the conductive part 522 is provided at the top of the substrate 200. When the second terminal 520 wraps around the substrate 200, the conductive part 522 is snap-fitted into the ring groove 240 and forms contact with the contact 410 at the top of the substrate 200, thereby further enhancing the stability of the connection between the second terminal 520 and the substrate 200.

[0034] Furthermore, on the basis of the above-mentioned embodiment, in combination with Figure 4 and Figure 5 As shown, a bump 310 is provided at the bottom of the rotating base 300, and a limiting hole 420 corresponding to the position of the bump 310 is provided on the brush piece 400. When the brush piece 400 is sleeved on the bottom of the rotating base 300, the bump 310 is inserted into the limiting hole 420, so that when the rotating base 300 rotates, the brush piece 400 can be driven to rotate synchronously.

[0035] Furthermore, on the basis of the above-mentioned embodiment, in combination with Figure 4 and Figure 5 As shown, a second through hole 250 is provided on the substrate 200, and the position of the second through hole 250 corresponds to the position of the first through hole 110. The rotating base 300 is inserted into the second through hole 250 and can rotate in the second through hole 250. Preferably, there is a support step 320 at the bottom of the rotating base 300. When the rotating base 300 is inserted into the second through hole 250, the support step 320 is stuck at the edge of the second through hole 250. In this way, when an axial external force is applied to the rotating base 300, the support step 320 will form a support between the rotating base 300 and the substrate 200, preventing the distance between the rotating base 300 and the base from being compressed, thereby enhancing the bearing capacity of the rotating base 300, protecting the brush piece 400 from being deformed by external extrusion, and eliminating quality hazards.

[0036] Details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, in any regard, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

Claims

1. A carbon film potentiometer, comprising a housing (100) and a substrate (200), wherein the housing (100) covers the substrate (200), a first through hole (110) is provided on the housing (100), a rotating seat (300) is installed between the housing (100) and the substrate (200), a brush sheet (400) is sleeved on the bottom of the rotating seat (300), the brush sheet (400) can rotate synchronously with the rotating seat (300), a contact (410) is provided at the bottom of the brush sheet (400), and a terminal assembly (500) is installed in the substrate (200), characterized in that: The terminal assembly (500) is wrapped inside a substrate (200), a carbon film resistor (210) is printed on the surface of the substrate (200), the contact (410) is in contact with the carbon film resistor (210), and the carbon film resistor (210) and the terminal assembly (500) are in surface contact on the top of the substrate (200).

2. The carbon film potentiometer according to claim 1, characterized in that: The terminal assembly (500) comprises a first terminal (510), a second terminal (520) and a third terminal (530); a through slot (220) is provided on a side wall of the substrate (200); when the first terminal (510), the second terminal (520) and the third terminal (530) are arranged inside the substrate (200), the first terminal (510), the second terminal (520) and the third terminal (530) extend out of the substrate (200) through the through slot (220).

3. The carbon film potentiometer according to claim 2, characterized in that: The first terminal (510) and the third terminal (530) comprise a welding portion (511) and a connecting portion (512); the welding portion (511) extends outside the substrate (200) through the through groove (220); and the connecting portion (512) is arranged inside the substrate (200) and forms surface contact with a carbon film resistor (210) printed on the top of the substrate (200).

4. The carbon film potentiometer according to claim 3, characterized in that: A snap-fitting portion (513) is provided at one end of the connecting portion (512), and a snap-fitting groove (230) is provided on the side wall of the substrate (200); when the first terminal (510) and the third terminal (530) are wrapped inside the substrate (200), the snap-fitting portion (513) is snap-fitted into the snap-fitting groove (230).

5. The carbon film potentiometer according to claim 4, characterized in that: A limiting portion (514) is provided at the other end of the connecting portion (512), and the height of the limiting portion (514) is higher than the height of the substrate (200).

6. The carbon film potentiometer according to claim 2, characterized in that: The second terminal (520) comprises a welding portion (511) and a conductive portion (522); the welding portion (511) extends outside the substrate (200) through the through slot (220); and the conductive portion (522) is arranged inside the substrate (200) and contacts the top contact (410) of the substrate (200) to form an electrical connection.

7. The carbon film potentiometer according to claim 6, characterized in that: The conductive part (522) is annular in shape, and an annular groove (240) matching the shape of the conductive part (522) is provided on the top of the substrate (200).

8. The carbon film potentiometer according to claim 1, characterized in that: A protrusion (310) is provided at the bottom of the rotating seat (300), and a limiting hole (420) corresponding to the position of the protrusion (310) is provided on the brush sheet (400).

9. The carbon film potentiometer according to claim 8, characterized in that: A second through hole (250) is provided on the substrate (200), the position of the second through hole (250) corresponding to the position of the first through hole (110), and a supporting step (320) is provided at the bottom of the rotating seat (300), and when the rotating seat (300) is inserted into the second through hole (250), the supporting step (320) is stuck on the edge of the second through hole (250).

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