CN110856091B

CN110856091B - Preamplifier for sound level meter

Info

Publication number: CN110856091B
Application number: CN201911181642.5A
Authority: CN
Inventors: 罗鹏; 谭校明
Original assignee: Hunan Shengyi Measurement And Control Technology Co ltd
Current assignee: Hunan Shengyi Measurement And Control Technology Co ltd
Priority date: 2019-11-27
Filing date: 2019-11-27
Publication date: 2021-02-12
Anticipated expiration: 2039-11-27
Also published as: CN110856091A

Abstract

The invention discloses a preamplifier for a sound level meter, and relates to the field of amplifiers. Including casing, working of plastics, thimble, PCB board, signal line and impedance element the inside cavity that is equipped with of casing, the cavity runs through the casing is equipped with in proper order along length direction in the cavity the working of plastics with the PCB board, thimble one end is stretched out outside the casing, the thimble other end passes behind the working of plastics fixed connection PCB board one end the PCB board other end is equipped with the signal line, the signal line stretches out outside the casing, the impedance element is fixed on the PCB board. The invention has simple structure and convenient assembly and disassembly, reduces the installation procedures of workers and saves the cost.

Description

Preamplifier for sound level meter

Technical Field

The invention relates to the field of amplifiers, in particular to a preamplifier for a sound level meter.

Background

The microphone is a transducer for converting acoustic signals into electric signals, and a test capacitor microphone is generally adopted in a sound level meter, and has the characteristics of stable performance, wide dynamic range, flat frequency response, small volume and the like. Due to the high impedance of the microphone, it cannot be connected directly to the front-end conditioning circuit of the sound level meter, which requires an impedance matching device, the so-called preamplifier, to be present between them. The prior preamplifier has more complex structure and troublesome installation, a PCB needs to be fixed by a fastening spiral ring, and the fastening spiral ring needs to be loosened when the PCB is taken out.

Disclosure of Invention

The invention aims to provide a preamplifier for a sound level meter, which has the advantages of simple structure, convenience in disassembly and assembly, reduction in the installation procedures of workers and cost saving.

In order to solve the technical problems, the technical scheme adopted by the invention is as follows: the utility model provides a preamplifier for sound level meter, includes casing, working of plastics, thimble, PCB board, signal line and impedance element the inside cavity that is equipped with of casing, the cavity runs through the casing is equipped with in proper order along length direction in the cavity the working of plastics with the PCB board, thimble one end is stretched out outside the casing, the thimble other end passes behind the working of plastics fixed connection PCB board one end the PCB board other end is equipped with the signal line, the signal line stretches out outside the casing, impedance element fixes on the PCB board.

Preferably, the diameter of the front section of the cavity in the shell is larger than that of the middle section, and the diameter of the middle section is larger than that of the tail section.

Preferably, the plastic part is a convex cylinder, the diameter of the large end of the convex cylinder is in tight fit with the diameter of the front section of the cavity of the shell, and the diameter of the small end of the convex cylinder is smaller than the diameter of the middle section of the cavity of the shell.

Still further preferably, the plastic part is provided with a through hole in the center, and the diameter of the through hole is larger than that of the thimble.

Further preferably, the width of the PCB board is larger than the diameter of the end section of the cavity of the housing and smaller than the diameter of the middle section of the cavity of the housing.

Preferably, the front end of the shell is provided with an external thread.

Preferably, the end face perpendicular to the housing axis is provided with a plurality of threaded holes.

Adopt the produced beneficial effect of above-mentioned technical scheme to lie in:

1. the plastic part is a convex column body with a large front part and a thin rear part, the large end of the convex column body is tightly matched with the front section of the cavity of the shell, and the plastic part enters the shell and just fills the front cavity of the shell, cannot continuously retreat, is firmly installed and looks beautiful when seen from the direction of the thimble.

2. The ejector pin is welded at the front end of the PCB, the width of the PCB is larger than the diameter of the rear section of the cavity of the shell, and the rear end of the PCB is propped against the rear section of the cavity of the shell, so that the ejector pin cannot move backwards when the microphone is installed, and if the PCB needs to be taken out, a screwdriver needs to be inserted into the through hole in the rear section of the cavity of the shell to forcedly prop against the PCB, so that a fastening spiral ring used in the past is omitted, the installation time of workers is shortened, and meanwhile, the PCB is easy and feasible to take out.

Drawings

FIG. 1 is a schematic cross-sectional view of the present invention;

in the figure: 1. the circuit board comprises a shell 2, a plastic part 3, a thimble 4, a PCB 5, a signal wire 6 and an impedance element.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

As shown in fig. 1, a preamplifier for sound level meter, which comprises a housing 1, the working of plastics 2, thimble 3, PCB board 4 and signal line 5, be equipped with the cavity in 1 inside of casing, the cavity runs through

casing

1, 1 inside cavity anterior segment diameter of casing is greater than the middle section diameter, the middle section diameter is greater than the end section diameter, be equipped with working of plastics 2 and PCB board 4 along length direction in proper order in the cavity, 2 appearances of working of plastics are convex cylinder, convex cylinder main aspects diameter and 1 cavity anterior segment diameter tight fit of casing, convex cylinder tip diameter is less than 1 cavity middle section diameter of casing. The width of the PCB 4 is larger than the diameter of the tail section of the cavity of the shell 1 and smaller than the diameter of the middle section of the cavity of the shell 1. A through hole is formed in the center of the plastic part 2, the diameter of the through hole is larger than that of the ejector pin 3, one end of the ejector pin 3 extends out of the shell 1, the other end of the ejector pin penetrates through the through hole of the plastic part 2 and then is fixedly connected with one end of the PCB 4, and the part, located outside the shell 1, of the ejector pin 3 is connected with the microphone. The other end of the PCB 4 is provided with a signal wire 5, the signal wire 5 extends out of the shell 1 and is welded on a main board of the sound level meter, and the PCB 4 is provided with an impedance element 6. The front end of the shell 1 is provided with an external thread which is connected with the microphone through the external thread. The rear end face of the rear end of the shell 1, which is perpendicular to the axis of the shell 1, is provided with a plurality of threaded holes, and the shell 1 is fixed on a sound level meter mainboard through the threaded holes.

The specific installation procedure of the invention is as follows: firstly, components such as an impedance element 6 on the PCB 4 are welded, then 2 signal wires 5 are welded on the PCB 4, the length of the signal wires 5 cannot be too long or too short, the main board of the sound level meter is convenient to weld, then the thimble 3 penetrates through the through hole of the plastic piece 2 from the large end of the plastic piece 2, and the tail part of the thimble 3 is welded in the groove at the front end of the PCB 4. And then, sending the assembly of the thimble 3, the plastic piece 2 and the PCB 4 into the shell 1 from one end of the shell 1 with the largest cavity diameter, and forcibly pressing the plastic piece 2 to ensure that the convex big end of the plastic piece 2 is completely immersed into the front cavity of the shell 1. During installation, the length of the signal wire 5 extending out of the shell 1 is only required to be about 2cm, a mainboard of the sound level meter is convenient to weld, and the length of the thimble 3 extending out of the shell 1 is only required to be about 3mm, so that a microphone is convenient to connect.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.

Claims

1. A preamplifier for a sound level meter is characterized by comprising a shell (1), a plastic piece (2), an ejector pin (3), a PCB (printed circuit board) (4), a signal wire (5) and an impedance element (6), a cavity is arranged in the shell (1) and penetrates through the shell (1), the diameter of the front section of the inner cavity of the shell (1) is larger than that of the middle section, the diameter of the middle section is larger than that of the tail section, the plastic part (2) and the PCB (4) are sequentially arranged in the cavity along the length direction, one end of the thimble (3) extends out of the shell (1), the other end of the thimble (3) penetrates through the plastic piece (2) and then is fixedly connected with one end of the PCB (4), the signal wire (5) is arranged at the other end of the PCB (4), the signal wire (5) extends out of the shell (1), and the impedance element (6) is fixed on the PCB (4); the appearance of the plastic part (2) is a convex cylinder, the diameter of the large end of the convex cylinder is tightly matched with the diameter of the front section of the cavity of the shell (1), and the diameter of the small end of the convex cylinder is smaller than the diameter of the middle section of the cavity of the shell (1).

2. Preamplifier for sound level meters according to claim 1, characterized in that the plastic part (2) is provided with a through hole in the centre, the diameter of said through hole being larger than the diameter of the spike (3).

3. Preamplifier for sound level meters according to claim 1, characterized in that the PCB board (4) width is larger than the housing (1) cavity end diameter and smaller than the housing (1) cavity middle diameter.

4. Preamplifier for sound level meters according to claim 1, characterized in that the front end of the housing (1) is provided with an external thread.

5. Preamplifier for sound level meters according to claim 1, characterized in that the end face perpendicular to the axis of the housing (1) is provided with threaded holes.